CN114745715A

CN114745715A - Secret key generating method, device, system, equipment and medium based on communication system

Info

Publication number: CN114745715A
Application number: CN202210522275.6A
Authority: CN
Inventors: 白景鹏; 刘国荣; 陈方杰
Original assignee: China Telecom Corp Ltd
Current assignee: China Telecom Corp Ltd
Priority date: 2022-05-13
Filing date: 2022-05-13
Publication date: 2022-07-12
Anticipated expiration: 2042-05-13
Also published as: CN114745715B

Abstract

The application provides a secret key generation method, a secret key generation device, a secret key generation system, secret key generation equipment and a secret key generation medium based on a communication system, and relates to the technical field of communication. The method comprises the following steps: during the channel detection, in a plurality of antennas, performing antenna switching on a first antenna of the previous channel detection to obtain a first antenna of the channel detection; receiving a first detection signal sent by second equipment through a first antenna of the current channel detection; extracting channel characteristic parameters of the first detection signal; under the condition that a preset detection ending condition is not reached, entering next channel detection, and ending the channel detection until the preset detection ending condition is reached to obtain channel characteristic parameters of a plurality of first detection signals; a first physical layer key is generated based on channel characteristic parameters of the plurality of first probe signals. According to the embodiment of the application, the security of the wireless network can be improved.

Description

Secret key generating method, device, system, equipment and medium based on communication system

Technical Field

The present application relates to the field of communications technologies, and in particular, to a method, an apparatus, a system, a device, and a medium for generating a secret key based on a communication system.

Background

As wireless networks have been developed, security issues of wireless networks have gradually attracted attention of those skilled in the art.

At present, in order to improve the security of the wireless network, it is often necessary for both communication parties to encrypt data transmitted in a channel by using a key. However, conventional key-encrypted information often poses security risks such as eavesdropping, counterfeiting, tampering, etc. of the key.

Therefore, how to improve the security of the wireless network becomes a problem to be solved.

It is to be noted that the information disclosed in the above background section is only for enhancement of understanding of the background of the present application and therefore may include information that does not constitute prior art known to a person of ordinary skill in the art.

Disclosure of Invention

The application provides a secret key generation method, a secret key generation device, a secret key generation system, secret key generation equipment and a secret key generation medium based on a communication system, which at least overcome the problem of insufficient security of a wireless network to a certain extent.

Other features and advantages of the present application will be apparent from the following detailed description, or may be learned by practice of the application.

According to an aspect of the present application, there is provided a key generation method based on a communication system, the communication system including a first device and a second device, the first device including a plurality of antennas, the method being applied to the first device, the method including:

during the channel detection, in a plurality of antennas, performing antenna switching on a first antenna of the previous channel detection to obtain a first antenna of the channel detection;

receiving a first detection signal sent by second equipment through a first antenna of the current channel detection;

extracting channel characteristic parameters of the first detection signal;

under the condition that a preset detection ending condition is not reached, entering next channel detection, ending the channel detection until the preset detection ending condition is reached, and obtaining channel characteristic parameters of a plurality of first detection signals;

a first physical layer key is generated based on channel characteristic parameters of the plurality of first probe signals.

In one embodiment, in a plurality of antennas, before performing antenna switching on a first antenna for previous channel sounding to obtain a first antenna for current channel sounding, the method includes:

determining an operating mode of a first device and an operating mode of a second device;

in the multiple antennas, performing antenna switching on a first antenna of a previous channel detection to obtain the first antenna of the current channel detection, including:

under the condition that at least one of the working mode of the first device and the working mode of the second device is a preset working mode, selecting a first antenna for current channel detection from at least one antenna, the number of which is greater than a preset number threshold, of the antennas of the first antenna for the previous channel detection;

the preset working mode is a working mode which represents that the equipment is in a high-speed moving state or the equipment is in a slow fading environment.

In one embodiment, in the multiple antennas, performing antenna switching on a first antenna of previous channel sounding to obtain a first antenna of this channel sounding, further includes:

and under the condition that the working mode of the first equipment and the working mode of the second equipment are not the preset working mode, selecting the first antenna for the current channel detection from at least one antenna, wherein the interval between the number of the antennas of the first antenna and the number of the antennas of the previous channel detection is less than or equal to a preset number threshold.

In one embodiment, in the multiple antennas, before performing antenna switching on the first antenna of the previous channel sounding to obtain the first antenna of the current channel sounding, the method further includes:

determining an amount of signal attenuation between the first device and the second device;

and under the condition that the signal attenuation is within a preset value range, performing antenna switching on a first antenna of the previous channel detection in the plurality of antennas to obtain the first antenna of the current channel detection.

In one embodiment, after determining the amount of signal attenuation between the first device and the second device, the method further comprises:

under the condition that the signal attenuation is out of a preset value range, receiving a second detection signal sent by second equipment through a preset second antenna during each channel detection, and extracting channel characteristic parameters of the received second detection signal until a preset detection end condition is reached to obtain channel characteristic parameters of a plurality of second detection signals;

and generating a second physical layer key according to the channel characteristic parameters of the plurality of second detection signals.

In one embodiment, before receiving, through the first antenna of the current channel sounding, the first sounding signal sent by the second device, the method further includes:

selecting a channel of the current channel detection from other channels except the channel of the previous channel detection in a plurality of channels of a preset channel set;

receiving a first detection signal sent by a second device through a first antenna of the current channel detection, including:

receiving a first detection signal sent by the second device through the channel detected this time through the first antenna detected this time,

the multiple channels of the preset channel set correspond to different sub-frequency bands of the preset working frequency band.

In one embodiment, the number of each channel in the plurality of channels is the result of sorting the frequency of the sub-band corresponding to each channel in the plurality of channels;

selecting a channel of the current channel detection from other channels except a channel of the previous channel detection in a plurality of channels of a preset channel set, wherein the channel of the current channel detection comprises the following steps:

determining the channel number of the channel detected at the previous time;

increasing the signal number by a preset integer to obtain an increased channel number;

determining the channel corresponding to the increased channel number as the channel of the current channel detection under the condition that the increased channel number is less than or equal to the maximum value of the channel number;

and when the increased channel number is greater than the maximum value, taking the channel corresponding to the initial channel number as the channel of the current channel detection.

In one embodiment, the method further comprises:

and during each channel detection, sending a third detection signal to the second equipment through the first antenna for each channel detection, so that the second equipment extracts the channel characteristic parameters of the third detection signal for each channel detection, and generates a third physical layer key corresponding to the first physical layer key according to the channel characteristic parameters of the third detection signal for multiple channel detections.

In one embodiment, generating the first physical layer key based on channel characteristic parameters of a plurality of first sounding signals includes:

quantizing the channel characteristic parameters of the first detection signals to obtain a first bit sequence;

and performing key agreement by using the first bit sequence and a second bit sequence to obtain a first physical layer key, wherein the second bit sequence is obtained by quantizing channel characteristic parameters of a third detection signal of the second device, which is used for detecting the channel for multiple times.

In one embodiment, before quantizing the channel characteristic parameters of the plurality of first sounding signals to obtain the first bit sequence, the method further includes:

determining, for each first probing signal, a transmission time interval between the first probing signal and an associated third probing signal, wherein the associated third probing signal and each first probing signal belong to the same channel sounding;

judging whether the transmission time interval is larger than the relevant time of a preset channel or not;

determining that the first detection signal is valid when the transmission time interval is less than or equal to the preset channel correlation time;

quantizing the channel characteristic parameters of the plurality of first detection signals to obtain a first bit sequence, including:

and quantizing the channel characteristic parameters of the effective first detection signals in the plurality of first detection signals to obtain a first bit sequence.

According to another aspect of the present application, there is provided a key generation method based on a communication system, the communication system including a first device and a second device, the first device including a plurality of antennas, the method being applied to the second device, the method including:

during the current channel detection, sending a first detection signal to a first antenna of the current channel detection of the first device, so that the first device extracts a channel characteristic parameter of the first detection signal after receiving the first detection signal, wherein the first antenna of the current channel detection is obtained by antenna switching of the first antenna of the previous channel detection in a plurality of antennas;

and under the condition that the preset detection ending condition is not reached, entering next channel detection until the preset detection ending condition is reached, ending the channel detection so that the first equipment obtains the channel characteristic parameters of the plurality of first detection signals after ending the channel detection, and generating the first physical layer key based on the channel characteristic parameters of the plurality of first detection signals.

According to still another aspect of the present application, there is provided a first device, the first device and a second device belonging to a communication system, the first device including a plurality of antennas, the first device including:

the antenna switching module is used for switching the antenna of a first antenna of the previous channel detection in the plurality of antennas during the current channel detection to obtain the first antenna of the current channel detection;

the signal receiving module is used for receiving a first detection signal sent by the second equipment through the first antenna of the current channel detection;

the parameter extraction module is used for extracting channel characteristic parameters of the first detection signal;

the processing module is used for entering next channel detection under the condition that a preset detection end condition is not reached, ending the channel detection until the preset detection end condition is reached, and obtaining channel characteristic parameters of a plurality of first detection signals;

a first key generation module, configured to generate a first physical layer key based on channel characteristic parameters of the first probe signals.

According to still another aspect of the present application, there is provided a second device, the second device and the first device belonging to a communication system, the first device including a plurality of antennas, the second device including:

the signal sending module is used for sending a first detection signal to a first antenna of the current channel detection of the first device during the current channel detection so as to enable the first device to extract a channel characteristic parameter of the first detection signal after receiving the first detection signal, wherein the first antenna of the current channel detection is obtained by antenna switching of the first antenna of the previous channel detection among a plurality of antennas;

the detection processing module is configured to enter next channel detection until a preset detection end condition is reached, end the channel detection so that the first device obtains channel characteristic parameters of the plurality of first detection signals after the channel detection is ended, and generate the first physical layer key based on the channel characteristic parameters of the plurality of first detection signals.

According to still another aspect of the present application, there is provided a communication system including:

the first device described above; and the combination of (a) and (b),

the second device described above.

According to still another aspect of the present application, there is provided an electronic device including: a processor; and a memory for storing executable instructions for the processor; wherein the processor is configured to perform the above-described communication system based key generation method via execution of the executable instructions.

According to yet another aspect of the present application, there is provided a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements the above-described communication system-based key generation method.

The method, the apparatus, the system, the device and the medium for generating a secret key based on a communication system according to the embodiments of the present application may perform antenna switching on a first antenna of a previous channel sounding in each channel sounding process to obtain the first antenna of the current channel sounding, receive a first sounding signal sent by a second device by using the first antenna of the current channel sounding, and extract a channel characteristic parameter of the first sounding signal. And generating a first physical layer key by using the channel characteristic parameters of a plurality of first detection signals acquired in the process of channel detection for a plurality of times under the condition that a preset detection end condition is reached. The first antenna is switched in any two adjacent channel detection processes, so that the space variable characteristic of a wireless channel can be introduced between the acquired channel characteristic parameters of the first detection signals. And when the preset detection ending condition is not met, entering next channel detection, acquiring the first detection signal again by using the first antenna during the next channel detection and extracting the channel characteristic parameter of the first detection signal, so that the channel characteristic parameter of the first detection signal can be acquired again after a certain time interval to introduce the time-varying characteristic of the wireless channel among the acquired channel characteristic parameters of the plurality of first detection signals. Therefore, according to the secret key generation method based on the communication system, the space variable characteristic and the time variable characteristic of the wireless channel are introduced between the channel characteristic parameters of the acquired first detection signals, so that the safety of the secret key is improved, and the safety of the wireless network is further improved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and together with the description, serve to explain the principles of the application. It is obvious that the drawings in the following description are only some embodiments of the application, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

Fig. 1 is a diagram illustrating a system architecture of a communication system according to an embodiment of the present application;

fig. 2 illustrates a system architecture diagram of an exemplary communications system provided by an embodiment of the present application;

fig. 3 illustrates a system architecture diagram of another exemplary communication system provided by an embodiment of the present application;

fig. 4 is a flowchart illustrating a method for generating a secret key based on a communication system in an embodiment of the present application;

fig. 5 is a schematic view illustrating a scenario of a key generation method based on a communication system according to an embodiment of the present application;

fig. 6 shows a schematic switching diagram of a first antenna according to an embodiment of the present application;

fig. 7 is a flowchart illustrating another key generation method based on a communication system according to an embodiment of the present application;

fig. 8 is a schematic diagram illustrating switching of a second antenna according to an embodiment of the present application;

fig. 9 is a schematic diagram illustrating switching of another second antenna provided in an embodiment of the present application;

FIG. 10 is a flowchart illustrating another method for generating a secret key based on a communication system according to an embodiment of the present application

FIG. 11 is a schematic diagram of a first apparatus in an embodiment of the present application;

FIG. 12 is a schematic diagram showing a second apparatus according to an embodiment of the present application;

fig. 13 is a logic diagram illustrating a key generation process based on a communication system according to an embodiment of the present application; and

fig. 14 shows a block diagram of an electronic device in an embodiment of the present application.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

Furthermore, the drawings are merely schematic illustrations of the present application and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and thus their repetitive description will be omitted. Some of the block diagrams shown in the figures are functional entities and do not necessarily correspond to physically or logically separate entities. These functional entities may be implemented in the form of software, or in one or more hardware modules or integrated circuits, or in different networks and/or processor devices and/or microcontroller devices.

It should be understood that the various steps recited in the method embodiments of the present application may be performed in a different order and/or in parallel. Moreover, method embodiments may include additional steps and/or omit performing the illustrated steps. The scope of the present application is not limited in this respect.

It should be noted that the terms "first", "second", and the like in the present application are only used for distinguishing different devices, modules or units, and are not used for limiting the order or interdependence relationship of the functions performed by the devices, modules or units.

It is noted that references to "a", "an", and "the" modifications in this application are intended to be illustrative rather than limiting, and that those skilled in the art will recognize that reference to "one or more" unless the context clearly dictates otherwise.

With the development of channels, wireless communication of communication devices on the channels often affects security due to the risk of eavesdropping. Therefore, in order to improve security of wireless communication, it is often necessary to encrypt wireless communication data.

Conventional encryption methods such as symmetric encryption and asymmetric encryption often require a trusted third party authority to distribute and manage keys of two communication parties, and often have a risk of eavesdropping due to the distribution process of the keys, and wireless communication information encrypted by the keys has security risks of eavesdropping, counterfeiting, tampering and the like.

Therefore, how to further improve the security of the wireless network becomes an urgent problem to be solved.

In a related art, a physical layer key may be used to encrypt communication to improve security of wireless transmission. For the physical layer key, it may be a key whose wireless channel characteristics are the key source. The generation process of the physical layer key can be basically divided into three steps of channel feature extraction, feature data quantization and key consistency negotiation.

In this technique, the communication device often uses the channel characteristic parameter to generate a physical layer key to encrypt data that needs to be transmitted to other devices, so as to improve the security of the wireless network by improving the randomness of the key through the randomness of the change of the channel characteristic parameter.

The physical layer key Generation Technology based on channel characteristics provides secure cryptographic services for both Communication parties by means of short-time reciprocity, time-varying property, fast space-varying property and randomness of channels for one of the key technologies for wireless network security of wireless network technologies such as 4G (4th Generation Mobile Communication Technology, fourth Generation Mobile Communication Technology), 5G (5th Generation Mobile Communication Technology, fifth Generation Mobile Communication Technology), 6G (6th Generation Mobile Communication Technology, sixth Generation Mobile Communication Technology).

The inventor finds that, for the technology of physical layer key generated by using the channel characteristic parameter, the security is often affected by the channel attenuation, for example, when the fading of the wireless communication channel changes slowly with time due to reasons such as in the indoor wireless communication scenario, the generated key sequence may be close to all 0 or all 1, thereby increasing the possibility of secret stealing and further affecting the security of the wireless communication.

Based on this, embodiments of the present application provide a method, an apparatus, a system, a device, and a medium for generating a secret key based on a communication system, which can perform antenna switching on a first device with multiple antennas in a channel feature extraction stage based on a multi-antenna technology, so that the first device can receive a first detection signal sent by a second device by using different first antennas between any two adjacent communications, and because spatial channel attenuation between different first antennas and the second device has independence, sufficient spatial variation can be brought to a channel feature parameter of the first detection signal during multiple channel detection. In addition, a certain time interval is provided between the first detection signals obtained in the two adjacent channel detections, so that sufficient time variation can be brought to the channel characteristic parameters of the first detection signals in the multiple channel detections. Correspondingly, the channel characteristic parameters of the first detection signal during multiple times of channel detection have a spatial change rate and a time change amount, so that the randomness of the physical layer key can be enhanced, and the security of the wireless network is further improved.

Before beginning to introduce a key generation scheme based on a communication system provided in an embodiment of the present application, a description is given of a communication system related to the present application.

Fig. 1 is a system architecture diagram of a communication system according to an embodiment of the present application. As shown in fig. 1, the communication system 100 may include a first device 110 and a second device 120.

The first device 110 may be a device with multiple antennas, which may acquire the channel characteristic parameters of multiple first sounding signals by antenna switching during multiple channel sounding procedures. Illustratively, the second device 120 may transmit a first sounding signal to the first device 110 during each channel sounding procedure. After the first device 110 performs antenna switching among the plurality of antennas, the first device receives the first sounding reference signal by using the switched first antenna, and extracts the channel characteristic parameter of the first sounding reference signal. And the first device 110 may also end channel sounding and obtain channel characteristic parameters of the plurality of first sounding signals after the preset sounding end condition is reached. A first physical layer key is then generated based on the channel characteristic parameters of the plurality of first sounding signals.

In the embodiment of the present application, the first device 110 and the second device 120 may be electronic devices that perform wireless communication with an antenna, such as but not limited to a smart phone, a tablet computer, a laptop portable computer, a desktop computer, a wearable device, an augmented reality device, a virtual reality device, and the like, and are not limited in particular.

In one embodiment, fig. 2 illustrates a system architecture diagram of an exemplary communication system provided by an embodiment of the present application. As shown in fig. 2, the first device 110 may have a plurality of antennas, such as m antennas 111 to 11m, where m is an integer greater than or equal to 2. The second device 120 may have a single antenna, antenna 121.

Accordingly, the second device 120 may transmit a first sounding signal to the first device 110 through the antenna 121 at each channel sounding. The first device 110 may select one antenna to receive the first sounding signal between the antennas 111 to 11m in an antenna switching manner.

In another embodiment, fig. 3 illustrates a system architecture diagram of another exemplary communication system provided by an embodiment of the present application. Fig. 3 differs from fig. 2 in that the second device 120 may also have multiple antennas, such as antennas 121 to 12p, where p is an integer greater than or equal to 2.

In one example, at each channel sounding, the second device 120 may perform antenna switching in 121 to 12p, and transmit a first sounding signal to the first device 110 using the switched antenna. The first device 110 may select one antenna to receive the first sounding signal between the antennas 111 to 11m in an antenna switching manner.

In another example, the second device 120 may transmit a first sounding signal to the first device 110 using the same antenna at each channel sounding. The first device 110 may select one antenna to receive the first sounding signal between the antennas 111 to 11m in an antenna switching manner.

After a communication system is introduced, a key generation method, a device, a system, an apparatus, and a medium based on the communication system according to an embodiment of the present application are described in sequence with reference to the drawings and the embodiments.

In an embodiment of the present application, a key generation method based on a communication system is provided, which may be performed by a first device shown in fig. 1 to 3. Next, the key generation method by the communication system will be described with reference to fig. 4 to 9.

Fig. 4 shows a flowchart of a method for generating a key based on a communication system in an embodiment of the present application, and as shown in fig. 4, the method for generating a key based on a communication system in the embodiment of the present application includes the following steps S410 to S460.

S410, during the current channel detection, in the multiple antennas of the first device, performing antenna switching on a first antenna of the previous channel detection to obtain a first antenna of the current channel detection.

In the embodiment of the present application, the channel characteristic parameters of the plurality of first sounding signals may be obtained through a plurality of channel sounding. Wherein, the current channel detection can be the one channel detection being performed.

For the first antenna, it may be an antenna selected among the plurality of antennas of the first device for communication with the second device. That is, the first device may receive a signal transmitted by the second device through the first antenna and may transmit a signal to the second device through the first antenna.

After the first antenna is introduced, S410 is explained next.

For S410, for other channel sounding except for the first channel sounding, one antenna may be selected from the remaining antennas except for the first antenna of the previous channel sounding as the first antenna of this channel sounding.

It should be noted that, for the 1 st channel sounding, for example, a pre-selected antenna may be used as the first antenna for the 1 st channel sounding. Alternatively, one antenna may be randomly selected as the first antenna among the plurality of antennas. Or, one antenna is selected as the first antenna according to a preset selection rule.

Next, an antenna switching method of the first antenna will be described.

In some embodiments, the antenna switching may be performed by using a preset antenna switching policy of the first antenna. The antenna switching strategy may be set according to an actual scene and specific requirements, for example, a preset number of antennas may be set at intervals each time. For example, the 1 st antenna is selected as the first antenna in the 1 st channel detection, the first antenna may be switched from the 1 st antenna to the 3 rd antenna in the second channel detection, and the first antenna may be switched from the 3 rd antenna to the 5th antenna in the third channel detection.

In other embodiments, the first antenna for the current channel sounding may be selected in a random switching manner among multiple antennas of the first device.

In an example, fig. 5 is a schematic view illustrating a scenario of a key generation method based on a communication system according to an embodiment of the present application. Next, a random switching process of the first antenna will be described by taking fig. 5 as an example.

As shown in fig. 5, in the n channel sounding processes of the first device 110 and the second device 120, the first device includes m antennas, and the first device 110 randomly selects the ith antenna, that is, the antenna i is used as the first antenna to communicate with the second device during the 1 st channel sounding. And, at the time of 2 nd channel sounding, the first device 110 randomly switches the first antenna to the jth antenna, i.e., antenna j, so as to receive the first sounding signal sent by the second device 120 by using antenna j. … …, the first device 110 randomly switches the first antenna to the kth antenna, i.e. antenna k, during the nth channel detection, so as to receive the first detection signal sent by the second device 120 through antenna k. Wherein n is an integer greater than or equal to 2, and i, j and k are integers less than or equal to m and greater than or equal to 1.

S420, receiving the first detection signal sent by the second device through the first antenna of the current channel detection.

For the first sounding signal, it may be a signal for sounding a wireless channel characteristic between the first device and the second device.

In some embodiments, the first probe signal may be periodically and actively transmitted by the second device, for example, the transmission period T of the first probe signal may be a preset value. Correspondingly, the channel sounding may be performed periodically, and the interval between two adjacent channel sounding is the transmission period T. Alternatively, the first device may return a third probe signal to the second device after receiving the first probe signal at each channel sounding.

In other embodiments, the first probe signal may be transmitted by the second device in response to the third probe signal. Illustratively, with continued reference to fig. 5, during each channel sounding procedure, the first device may transmit a third sounding signal to the second device. The second device returns the first probe signal to the first device in response to the third probe signal. For example, the third probing signal may be transmitted periodically, and the transmission period T of the third probing signal may be a preset value.

S430, extracting channel characteristic parameters of the first sounding signal.

For the channel characteristic parameter, it is used for a characteristic parameter reflecting the transmission characteristic of the communication channel between the first device and the second device. In some embodiments, the channel characteristic parameter may be, but is not limited to, signal strength, channel impulse response, channel frequency response, channel state information, angle of arrival, channel amplitude, channel phase, channel envelope, channel propagation delay, etc. Illustratively, the channel characteristic parameter may be a signal strength. It should be noted that the signal strength has the characteristic of being easy to collect, and can reduce the calculation pressure of the key generation process on the first device, so as to improve the key generation efficiency.

In some embodiments, S430 may include: the first device measures and records the signal strength of the received first probe signal after receiving the first probe signal.

In one example, the signal strength of the first probe signal may be stored in a matrix form. For example, if there are q channel detections performed in each channel detection cycle, m channel detections are performed, that is, m is l q, and l and q are integers greater than or equal to 1. The signal strengths of the m first probe signals acquired through the m channel probes may be stored in the matrix memory of l × q. The signal strengths of q first detection signals acquired by q channel detections in the same round of channel detection are stored in the same row of the matrix Ra, and the signal strengths of the first detection signals acquired by different rounds of channel detections are stored in different rows of the matrix Ra. For example, the signal strength of the b1 column located at the a1 th row in the matrix may be the signal strength value of the first probe signal received by the first device at the b1 th channel detection of the a1 th round.

S440, entering the next channel detection if the preset detection end condition is not met.

After entering the next channel sounding, the next channel sounding may be regarded as a new current channel sounding in S440, and the above steps S410 to S430 are executed again.

As for the preset sounding end condition, it may be a condition that needs to be satisfied when the channel sounding can be ended.

In some embodiments, the preset probing end condition may include: the channel detection times are larger than or equal to a preset time threshold value. The preset number threshold may be set according to actual conditions and specific key setting requirements, which is not specifically limited.

In other embodiments, the preset probing end condition may include: the total quantity of the acquired channel characteristic parameters of the first detection signal reaches a preset quantity. The preset number may be the number of channel characteristic parameters required for generating the first physical layer key. The specific value of the preset number may be determined according to an actual situation or a key generation requirement, which is not particularly limited.

In still other embodiments, the preset probing ending condition may include: the total amount of the acquired channel characteristic parameters of the first probe signal that can be used for generating the first physical layer key reaches a preset amount.

It should be noted that, according to the embodiment of the present application, other channel ending conditions that can ensure that the obtained channel characteristic parameter of the first probe signal can meet the requirement of generating the number of the first physical layer keys may also be set according to an actual scene and specific requirements, which is not described herein again.

And S450, ending the channel detection until a preset detection ending condition is reached, and obtaining the channel characteristic parameters of the plurality of first detection signals.

In S450, if n times of channel sounding are performed when the preset sounding condition is met, each time of channel sounding will obtain a channel characteristic parameter of the first sounding signal, and n channel characteristic parameters may be obtained in total through n times of channel sounding. Wherein each channel characteristic parameter corresponds to one channel detection.

S460, generating a first physical layer key based on the channel characteristic parameters of the plurality of first probe signals.

And the first physical layer key is used for encrypting the wireless communication information transmitted from the first device to the second device and decrypting the wireless communication information sent by the second device to the first device.

In some embodiments, S460 may include step a1 and step a2 described below.

Step a1, quantizing the channel characteristic parameters of the first detection signals to obtain a first bit sequence.

For quantization, it may convert the channel characteristic parameter into a bit sequence consisting of 0 and/or 1.

In one embodiment, step A1 may include steps A11-A13, described below.

In step a11, the channel characteristic parameters of the first sounding reference signals may be divided into a plurality of quantization intervals, for example, if 9 channel characteristic parameters are included, the 1 st to 3 rd channel characteristic parameters may be used as one quantization interval, the 4th to 6th channel characteristic parameters may be used as another quantization interval, and the 7 th to 9 th channel characteristic parameters may be used as another quantization interval.

Alternatively, the channel characteristic parameters of the plurality of first sounding signals may be regarded as one quantization interval. The embodiment of the present application does not specifically limit the way in which the quantization interval is defined.

Step a12, determining a quantization reference amount of each quantization interval according to a plurality of channel characteristic parameters in the quantization interval.

For example, the quantization reference amount may be a reference value capable of measuring whether each channel characteristic parameter is quantized to 0 or 1 within the quantization interval. For example, the quantization reference amount may be a median value, an average value, or the like of a plurality of channel characteristic parameters within the quantization interval. Or may be a preset value, which is not limited.

Step a13, quantizes each channel characteristic parameter in each quantization interval to 0 or 1 according to the quantization reference quantity. Illustratively, if a certain channel characteristic parameter is greater than or equal to the quantization reference quantity, it is quantized to 1. Similarly, if a certain channel characteristic parameter is smaller than the quantization reference amount, it is quantized to 0.

In other embodiments, step a1 may include step a14 and step a15 described below.

Step a14, classifying the channel characteristic parameters of the first probing signals, and determining the category to which the channel characteristic parameter of each first probing signal belongs.

Step a15, determining the code corresponding to the category to which the channel characteristic parameter of each first probe signal belongs as the quantized value of the channel characteristic parameter of each first probe signal. Wherein different classifications correspond to different code values.

For example, if 4 classes, i.e., class 1-class 4, are included, the corresponding code values are 00, 01, 11, and 10, respectively. Accordingly, if a certain channel characteristic parameter is classified into class 1, its quantization value is determined to be 00. If a certain channel characteristic parameter is classified into class 2, its quantization value is determined to be 01. If a certain channel characteristic parameter is classified into class 3, its quantized value is determined to be 11. If a certain channel characteristic parameter is classified into class 4, its quantization value is determined to be 10.

It should be noted that the specific number of categories may be set according to actual situations and specific needs, such as 2 categories, 4 categories, 8 categories, and the like, which is not specifically limited.

It should be noted that, according to the embodiment of the present application, other manners capable of quantizing a plurality of channel characteristic parameters into a bit sequence may be selected according to actual situations and specific needs, which is not limited in this respect.

Step a2, performing key agreement by using the first bit sequence and a second bit sequence to obtain a first physical layer key, where the second bit sequence is obtained by quantizing the channel characteristic parameter of a third probe signal of the second device, where the third probe signal is obtained by channel probing for multiple times.

In one embodiment, step a2 may include steps a21 through a23 described below.

Step A21, performing key reconciliation on the first bit sequence and the second bit sequence to obtain an initial key IK of the first device_aAnd an initial key IK of the second device_b。

For key reconciliation, it is used to discard or correct differences in keys generated at both ends. Illustratively, key reconciliation can be performed by a Cascade negotiation algorithm (i.e., a key negotiation algorithm), a BBBSC algorithm (i.e., a key negotiation algorithm), and Winnow (i.e., a key negotiation algorithm).

In one example, to improve key generation efficiency, a Cascade negotiation algorithm may be employed for key reconciliation.

In this example, since the Cascade negotiation algorithm can improve the efficiency of key reconciliation and reduce the complexity of error correction, the efficiency of generating the first physical layer key can be improved.

Step A22, initial Key IK for first device_aAnd an initial key IK of the second device_bAnd carrying out key consistency check to obtain a consistency check result.

Wherein the key consistency check is used to determine an initial key IK of the first device_aAnd the initial key IKb of the second device. Accordingly, the consistency check results are: initial key IK of first device_aThe same as the initial key IKb of the second device, or the initial key IK of the first device_aDifferent from the initial key IKb of the second device.

In one example, step a22 includes steps a221 through a228 described below.

Step A221, the first device uses an initial Key IK_aAnd encrypting the first random number ra to obtain a first encryption operation result, and sending the first encryption operation result to the second equipment.

Step A222, the second device uses the initial key IK_bFor the first encryption operation resultAnd decrypting to obtain a second random number ra'.

In step a223, the second device calculates the second random number ra 'by using a preset calculation rule, so as to obtain a third random number sra'.

For example, the second random number ra 'may be multiplied by a preset multiple, such as by 2, to obtain a third random number sra'.

For another example, the second random number ra 'may be added to the preset data to obtain a third random number sra'

It should be noted that the operation may also be performed by using another operation rule negotiated with the second device in advance, which is not particularly limited.

Step A224, the second device uses the initial key IK_bEncrypting the third random number sra' to obtain a second encryption operation result, and sending the second encryption operation result to the first device.

Step A225, the first device decrypts the second encryption operation result to obtain a fourth random number (sra ')'.

In step a226, the first device operates the first random number ra according to a preset operation rule, so as to obtain a fifth random number sra.

For the preset operation rule, reference may be made to the description of step a223 in the above section of the embodiment of the present application, which is not described herein again. For example, the first random number ra may be multiplied by 2 to obtain the fifth random number sra.

In step a227, the first device compares the fifth random number sra with the fourth random number (sra ')' to obtain a comparison result indicating whether the two are the same. Wherein, the comparison results can be the same or different.

Step A228, the second device performs key consistency check based on the random number rb to obtain a comparison result. The key consistency check process is the same as the above steps a221 to a 227.

Step a229, in case that the comparison result of the first device and the comparison result of the second device are both the same, determining the initial key IK of the first device_aIdentical to the initial key IKb of the second device.

In one embodiment, in the case that the comparison result of the first device and/or the comparison result of the second device are not the same, the initial key IK of a device may be determined_aUnlike the initial key IKb of the second device, i.e., the first device fails to negotiate a key with the second device.

It should be noted that, the embodiment of the present application may also determine the initial key IK of the first device by other manners besides the above steps a221-a228_aAnd an initial key IK of the second device_bThe key consistency of (2) is not particularly limited.

Step A23, the result of the consistency check is the initial key IK of the first device_aThe initial key IKa of the first device is key enhanced to obtain the first physical layer key when the initial key IKb of the second device is the same.

For key enhancement, it is used to enhance the security of the key. In one embodiment, the initial key IKa of the first device may be compressed using a compression function to obtain the first physical layer key. Illustratively, the initial key IKa of the first device may be key enhanced using a hash function.

Through key enhancement, a part of secure keys can be compressed into information which is not easily utilized by an eavesdropper, and the security of the keys is further improved.

Through the steps a21 to a23, the problem that the first physical layer key is inconsistent with the third physical layer key of the second device due to inconsistency of the first bit sequence and the second bit sequence caused by noise and the like can be avoided, and further, the problem that the wireless communication information between the first device and the second device cannot be correctly encrypted and decrypted due to the problem can be avoided, so that the generation efficiency of the first physical layer key is ensured.

It should be noted that, according to specific situations and actual requirements, a manner other than the above-mentioned step a21 to step a23 may be selected to perform negotiation based on the first bit sequence and the second bit sequence to generate the first physical layer key and the third physical layer key with consistency, which is not limited in particular.

It should be further noted that, according to the embodiment of the present application, other ways may also be selected to generate the first physical layer key based on the first bit sequence according to practical situations and specific requirements, which is not particularly limited.

The secret key generation method based on the communication system provided by the embodiment of the application can perform antenna switching on the first antenna of the previous channel detection in each channel detection process to obtain the first antenna of the current channel detection, receive the first detection signal sent by the second device by using the first antenna of the current channel detection, and extract the channel characteristic parameter of the first detection signal. And generating a first physical layer key by using the channel characteristic parameters of a plurality of first detection signals acquired in the process of channel detection for a plurality of times under the condition that a preset detection end condition is reached. Because the first antenna is switched in any two adjacent channel detection processes, the space variable characteristic of a wireless channel can be introduced between the channel characteristic parameters of the obtained multiple first detection signals. And when the preset detection ending condition is not met, entering next channel detection, acquiring the first detection signal again by using the first antenna during the next channel detection and extracting the channel characteristic parameter of the first detection signal, so that the channel characteristic parameter of the first detection signal can be acquired again after a certain time interval to introduce the time-varying characteristic of the wireless channel among the acquired channel characteristic parameters of the plurality of first detection signals. Therefore, according to the secret key generation method based on the communication system, the space variable characteristic and the time variable characteristic of the wireless channel are introduced between the channel characteristic parameters of the acquired first detection signals, so that the safety of the secret key is improved, and the safety of the wireless network is further improved.

Moreover, it should be noted that, since the multi-antenna technology has already been applied in a wireless network, such as a base station antenna in a mobile communication wireless network, there is no need to develop and customize a multi-antenna system, and therefore the key generation based on the communication system provided in the embodiment of the present application also has the characteristic of simple implementation.

In some embodiments, the method for generating a key based on a communication system provided by the embodiment of the present application may further include the following step B1.

Step B1, during each channel detection, sending a third detection signal to the second device through the first antenna for each channel detection, so that the second device extracts the channel characteristic parameters of the third detection signal for each channel detection, and generates a third physical layer key corresponding to the first physical layer key according to the channel characteristic parameters of the third detection signal for multiple channel detections.

For the third physical layer key, the second device may quantize the channel characteristic parameter of the third detection signal obtained through multiple channel detections, to obtain a second bit sequence, and then perform key agreement with the first bit sequence to obtain the third physical layer key. Illustratively, the third physical layer key is the same as the first physical layer key, so that the second device can correctly decrypt the data sent by the first device and encrypted by the first physical layer key after receiving the data. And after the second device encrypts the data by using the third physical layer key and transmits the encrypted data to the first device, the first device can correctly decrypt the encrypted data by using the first physical layer key.

For step B1, the second device may receive the third sounding signal by using the same antenna during multiple channel sounding, or the second device may perform antenna switching during each channel sounding and receive the third sounding signal by using the switched antenna, which is not limited in this respect.

In one example, in order to ensure consistency of physical layer keys of both communication parties, the first probe signal and the third probe signal at each channel detection may use the same channel. Illustratively, with continued reference to fig. 5, as in the first channel sounding, the first device 110 may transmit a third sounding signal to the second device 120 through antenna i on channel a. The second device 120 transmits a first sounding signal on channel a to antenna i of the first device 110. At the second channel sounding, the first device 110 may transmit a third sounding signal on channel b to the second device 120 through antenna j. The second device 120 transmits a first sounding signal on channel b to antenna j of the first device 110. … …, similarly, at the nth channel sounding, the first device 110 may send a third sounding signal to the second device 120 through antenna k on channel c. The second device 120 transmits a first sounding signal on channel c to antenna k of the first device 110.

It should be noted that, in the embodiment of the present application, the execution sequence between step S420 and step B1 is not specifically limited. That is, in each channel sounding, the first device may first send the third sounding signal to the second device through the channel sounding first antenna of this time, and then the second device sends the first sounding signal to the first antenna of the channel sounding of this time of the first device. Alternatively, the second device may send the first probe signal to the first antenna of the first device for channel sounding this time, and then the first device returns the third probe signal to the second device through the first antenna of the channel sounding this time. Alternatively, the first device and the second device may independently transmit a sounding signal to each other at each channel sounding. The embodiment of the present application is not particularly limited to this.

In some embodiments, the key generation method based on the communication system may further include the following steps C1 to C3 before S460.

Step C1, for each first probe signal, determines a transmission time interval of the first probe signal and the associated third probe signal.

Wherein associating the third sounding signal with each of the first sounding signals belongs to the same channel sounding. Illustratively, the third sounding signal at the first channel sounding is an associated third sounding signal of the first sounding signal at the first channel sounding.

In one example, the transmission time interval may be the difference between the transmission time instant of the first probe signal and the transmission time instant of the associated third probe signal. The sending time of the probe signal may be the time when the probe signal sender sends the probe signal.

In another example, the transmission time interval may be the difference between the time of receipt of the first probe signal and the time of receipt of the associated third probe signal. The receiving time of the probe signal may be the time when the probe signal receiving side receives the probe signal.

Step C2, determine whether the transmission time interval is greater than the predetermined channel correlation time.

The preset channel coherence time may represent a period of time in which the variation of the channel characteristics is approximately zero. For example, the preset channel coherence time may be set according to actual conditions and specific requirements, which is not described in detail herein.

Step C3, determining that the first probing signal is valid when the transmission time interval is less than or equal to the predetermined channel correlation time.

In step C3, if the transmission time interval is less than or equal to the preset channel coherence time, the channel characteristic parameter of the first sounding signal and the channel characteristic parameter of the third sounding signal during the second channel sounding are the same or approximately the same.

Accordingly, in the case where the key generation method based on the communication system further includes the above-described steps C1 through C1, the step S460 may include the following step C4.

And step C4, quantizing the channel characteristic parameters of the first detection signals in the plurality of first detection signals to obtain a first bit sequence.

By the embodiment, because the first probe signal and the third probe signal have reciprocity within the preset channel coherence time, the measured values of the channel characteristic parameters of the probe signals of both communication parties are approximately equal, so that the consistency of the first physical layer key and the third physical layer key can be ensured, and the key generation efficiency can be improved.

In one embodiment, to ensure the key generation efficiency, step C2 is followed by step C5.

Step C5, if the transmission time interval is greater than the preset channel coherence time, determining that the first detection signal in the current channel detection is invalid, and discarding the channel characteristic parameter of the first detection signal in the current channel detection. Optionally, in order to ensure the key consistency of both communication parties, the second device may also discard the channel characteristic parameter of the third probing signal measured in the channel probing process of this time.

By the embodiment, invalid channel characteristic parameters can be discarded, so that the key calculation pressure of the equipment is reduced, and the key generation efficiency is improved.

In some embodiments, in order to ensure the randomness of the physical layer key, the key generation method based on the communication system may further include the following step D1 before S410.

Step D1, selecting the channel of the current channel detection from the channels except the channel of the previous channel detection in the plurality of channels of the preset channel set.

The plurality of channels of the preset channel set correspond to different sub-frequency bands of the preset working frequency band. The number of the preset working frequency bands and the number of the channels can be set according to actual conditions and specific requirements, and details are not repeated. For example, if the preset channel set includes 10 channels, the preset operating band may correspond to 10 sub-bands, where channel 1 corresponds to sub-channel 1, channel 2 corresponds to sub-channels 2 and … …, and channel 10 corresponds to sub-band 10.

In one example, each channel in the plurality of channels is numbered as a result of sorting of frequencies of the sub-bands corresponding to each channel in the plurality of channels.

Illustratively, if the predetermined operating band is 100MHz (megahertz) -120MHz, it is divided into 100 channels, for example, a sub-band of 100MHz-100.2MHz corresponds to a channel numbered 000, a sub-band of 100.2MHz-100.4MHz corresponds to a channel numbered 001, and … …, a sub-band of 119.8MHz-120 MHz corresponds to a channel numbered 099. Correspondingly, the 100 channels with the signal numbers 000-.

In one example, the channel of the current channel sounding may be selected at preset intervals, and accordingly, the step D1 may include the following steps D11 to D14.

And D11, determining the channel number of the channel detected in the previous channel detection.

And D12, increasing the signal number by a preset integer to obtain the increased channel number.

In one example, the preset integer, that is, the channel sampling interval Δ C, may be set according to actual conditions and specific requirements, for example, the preset integer is set under the condition that it is ensured that channel interference does not occur between channels.

Alternatively, the preset integer may be set to a first value when one of the first device and the second device is in a high-speed moving state, and may be set to a second value when both the first device and the second device are in a low-speed moving state. Wherein the first value is greater than the second value.

It should be noted that, because the channel interference is often aggravated when the device is in the high-speed moving state, the preset value may be dynamically adjusted according to the moving mode of the device through this embodiment, so that the influence of the channel interference on the physical layer key generation process may be prevented.

For step D12, for example, if the channel in the first channel detection corresponds to the initial channel number C₀Channel number C corresponding to the channel in the second channel sounding₀+ΔC。

And D13, determining the channel corresponding to the increased channel number as the channel of the current channel detection when the increased channel number is less than or equal to the maximum value of the channel number.

For example, if the maximum value of the channel number is 5 and the predetermined integer is 2, if the channel number corresponding to the previous channel sounding is less than or equal to 3 and the increased channel number is 5 (less than or equal to the maximum value of 5), the channel number corresponding to the current channel sounding is 5.

In step D14, when the increased channel number is greater than the maximum value of the channel number, the channel corresponding to the initial channel number is used as the channel for the channel sounding. Note that the initial channel number C is₀The initial value may be an initial value of a channel number, and the initial value may be set according to actual conditions and specific requirements, which is not described in detail herein.

For example, if the last channel number is 5, the increased channel number is 7 (greater than the maximum value 5 of the channel numbers), and the channel of the current channel sounding may be set as the initial channel number, that is, the number 1.

Accordingly, in the case where step D1 is further included before S410, step S410 may include step D2 described below.

And step D2, receiving, by the first antenna of the current channel detection, a first detection signal sent by the second device through the channel of the current channel detection.

For example, if the channel number of the current channel sounding is 1, the first sounding signal transmitted through the channel 1 by the second device may be used.

In one example, before step D2, the first device may send a third sounding signal to the channel by using the current channel sounding, and then the second device sends the first sounding signal to the first device by using the same channel after receiving the third sounding signal of the current channel sounding.

In a specific example, to facilitate understanding of the embodiments of the present application as a whole, a key generation method based on a communication system provided in the embodiments of the present application is described next with reference to fig. 6.

Fig. 6 shows a switching diagram of a first antenna according to an embodiment of the present application. As shown in fig. 6, if the first device includes 3 antennas, i.e., antennas 1 to 3, and the predetermined channel set includes 5 channels, i.e., channels 1 to 5.

During the first channel detection, the antenna 1 may be selected to receive a first detection signal sent by the second device through the channel 1. At the time of second channel detection, the first antenna is randomly switched from the antenna 1 to the antenna 3, and the communication channel is switched from the channel 1 to the channel 3, that is, the antenna 3 is used for receiving a first detection signal sent by the second device through the channel 3.… …, at the time of the nth channel detection, the first antenna is randomly switched from the antenna 3 to the antenna 2, and the communication channel is switched from the channel 3 to the channel 5, that is, the first detection signal sent by the second device through the channel 5 is received by the antenna 2.

For example, taking the antenna switching strategy shown in fig. 6 as an example, if channel detection is performed 3 times in 4 rounds and each round, and channel detection is performed 12 times in total, a matrix generated by the channel characteristic parameters of the 12 channel detection processes may be represented as the following matrix:

wherein any element in the matrix

And the channel characteristic parameter of the first detection signal received by the first device through the antenna z on the channel with the channel number g is shown when the channel is detected for the y time in the x round. Wherein x is any positive integer less than or equal to 4, y is any positive integer less than or equal to 3, g is any value of 1, 3 or 5, and z is a random number from 1 to 3.

In another example, to ensure the randomness of the first physical layer key, the channel of the current channel sounding may be randomly selected. For example, if the channel of the previous channel sounding is the channel 000, the channel of the current channel sounding may be selected from the channels 001-.

In some embodiments, the channel switching may be performed by the second device at each channel sounding, and the first sounding signal may be transmitted to the first device using the switched channel, and then the first device may transmit the third sounding signal to the second device through the same channel.

It should be noted that, for the channel switching manner of the second device, reference may be made to the related description of the above-mentioned part of the embodiment of the present application through step B1 and steps B21-B22, which is not described herein again.

According to the embodiment of the application, different channels correspond to different sub-frequency bands, so that a frequency-varying characteristic can be introduced among channel characteristic parameters of a plurality of acquired first detection signals in a channel switching mode, and therefore sufficient frequency-varying characteristics, time-varying characteristics and space-varying characteristics can be introduced for a first physical layer secret key, the safety of the secret key is further improved, and the safety of a wireless network is further improved.

In some embodiments, in order to improve the security of the key, before S410, the key generation method based on the communication system may further include the following step E1.

Step E1, determining the operation mode of the first device and the operation mode of the second device.

For the operating mode, it may be an operating mode of the wireless communication device, which may include an open loop transmit diversity mode, an open loop spatial multiplexing mode, a closed loop spatial multiplexing mode, a MU-MIMO (Multi User MIMO, Multi User spatial multiplexing) mode, or a closed loop transmit diversity mode with rank 1.

Accordingly, in case that the key generation method based on the communication system further includes the step E1 before S410, S410 may include the following step E21.

Step E21, when at least one of the operation mode of the first device and the operation mode of the second device is the preset operation mode, selecting the first antenna for channel detection this time from at least one antenna whose antenna number interval with the first antenna for channel detection last time is greater than the preset number threshold.

For the preset number threshold, it may be set according to actual conditions and specific antenna switching requirements, which is not described in detail herein.

For the antenna switching manner, if 12 antennas, i.e., antennas 0 to 11, are included, the preset number threshold is 5, and if the first antenna of the previous signal detection is antenna 3, the first antenna may be selected from antennas 9 to 11 in the current channel detection.

For the preset operation mode, it may be an operation mode that characterizes that the device is in a high-speed moving state or that the device is in a slow fading environment. The high-speed moving state may be determined according to a moving speed of the device, for example, when the moving speed of the device is greater than a preset moving speed threshold, it is determined that the device is in a high-speed moving mode. The preset moving speed threshold value may be set according to an actual scene and specific requirements, which is not described in detail herein.

For a slow fading environment, it may be determined based on the amount of signal attenuation in the environment in which the device is located. For example, if the signal attenuation of the device is less than or equal to the preset attenuation threshold, the device may be considered to be in a slow fading environment.

In some embodiments, the preset operating mode may include at least one of the following modes 11-14.

Mode 11, transmit diversity mode.

It should be noted that, because the transmit diversity mode is often suitable for the device in the high-speed mobile environment, when the channel interference is aggravated due to the device in the high-speed mobile environment, the first antenna switching manner of this embodiment can ensure that the interval between the first antennas is large enough, so as to avoid the influence of the channel interference on the randomness of the first physical layer key.

Mode 12, open-loop spatial multiplexing mode.

It should be noted that, because the open-loop spatial multiplexing mode is often suitable for a cell center user or a device in a high-speed mobile environment, and because the signal attenuation of the cell center user is often small, the first antenna switching manner of this embodiment can enable the interval between the first antennas used in the two adjacent channel detection processes to be sufficiently large, so that a sufficiently large spatial variable characteristic of a wireless channel can be introduced in this manner when the signal attenuation is small, and the randomness of the first physical layer key is improved. And when the device is in a high-speed mobile environment, the channel interference is often aggravated, and by the first antenna switching mode of the embodiment, the sufficient interval between the first antennas can be ensured, so that the influence of the channel interference on the randomness of the first physical layer key is avoided.

Mode 13, closed-loop spatial multiplexing mode of 2 codewords.

It should be noted that, because the closed-loop spatial multiplexing mode of the 2 codeword is often suitable for a cell center user, and because the signal attenuation of the cell center user is often small, the first antenna switching manner of this embodiment can make the interval between the first antennas used in the two adjacent channel detection processes large enough, so that when the signal attenuation is small, a sufficiently large spatial variable characteristic of a wireless channel is introduced by this manner, and the randomness of the first physical layer key is improved.

Mode 14, MU-MIMO mode.

It should be noted that, because the device often selects the MU-MIMO mode in the indoor scene and the signal attenuation of the indoor scene is often slow, the first antenna switching manner of this embodiment can make the interval between the first antennas used in the two adjacent channel detection processes large enough, so that the spatial variable characteristic of the wireless channel large enough can be introduced in this manner when the signal attenuation is small, and the randomness of the first physical layer key is improved.

In some embodiments, after step E1, the method for key generation based on a communication system may further include step E22.

Step E22, in a case that the working mode of the first device and the working mode of the second device are not both the preset working mode, selecting the first antenna for channel detection this time from at least one antenna whose number interval with the antenna number of the first antenna for channel detection last time is smaller than or equal to the preset number threshold.

For the antenna switching method, if 12 antennas are included, the preset number threshold is 5, and if the first antenna of the previous signal detection is antenna 3, the first antenna may be selected from antennas 0 to 10 in the current channel detection.

In step E22, when the operation mode of the first device and the second device is one of the following modes 21 to 22, the antenna switching manner shown in step E22 may be adopted.

Mode 21, closed-loop spatial multiplexing mode of 1 codeword.

It should be noted that, because the closed-loop spatial multiplexing mode of the 1 codeword is often applicable to cell edge users and to a low-speed mobile mode, it can be ensured that the signal attenuation is large and the channel interference is light at this time, and at this time, the first antenna switching mode provided by this embodiment is selected, so that the first antenna switching is facilitated while the randomness of the first physical layer key is ensured.

Mode 22, closed loop transmit diversity mode of rank 1.

It should be noted that, since the closed-loop transmit diversity mode with rank 1 is often used in a traffic-dense area, and the traffic-dense area often has a characteristic of fast signal attenuation, it may be convenient to switch the first antenna while ensuring the randomness of the first physical layer key.

By the embodiment, the switching strategy of the first antenna can be flexibly adjusted according to the working modes of the two communication parties, and the randomness of the first physical layer key is further ensured.

Fig. 7 shows a flowchart of another key generation method based on a communication system according to an embodiment of the present application. The embodiments of the present application are optimized based on the embodiments described above, and the embodiments of the present application may be combined with various alternatives in one or more of the embodiments described above.

As shown in fig. 7, the key generation method based on the communication system may include the following steps S710 to S770.

And S710, determining a signal attenuation amount between the first device and the second device.

The signal attenuation amount may be a characteristic amount capable of reflecting the degree or magnitude of signal attenuation, such as a signal intensity change amount, and is not particularly limited.

In some embodiments, the amount of signal attenuation may be determined from the amount of change in signal strength of a probe signal transmitted between two devices. For example, a first signal strength of the detection signal may be acquired when one of the first device and the second device emits the detection signal. And acquiring a second signal strength of the detection signal when the other of the first device and the second device receives the detection signal. And taking a difference between the first signal strength and the second signal strength as a signal attenuation amount between the first device and the second device.

It should be noted that, in the embodiment of the present application, the signal attenuation amount may be determined in other manners, which is not limited to this. For example, the difference between the strength value of the signal received in the current channel sounding and the strength value of the signal received in the last channel sounding may be used.

And S720, under the condition that the signal attenuation is within the preset value range, performing antenna switching on a first antenna of the previous channel detection in the plurality of antennas to obtain the first antenna of the current channel detection.

For the preset value range, the attenuation amount range corresponding to the slow attenuation of the signal may be used, that is, when the signal attenuation amount of the device is within the preset value range, the device may be considered to be in a slow attenuation environment. For example, the preset value range may be a range with 0 as a lower limit value and a first preset attenuation threshold value as an upper limit value. The first preset attenuation threshold is used for measuring the signal attenuation speed, and may be set according to actual conditions and specific requirements, which is not described in detail herein.

It should be noted that other contents of S720 may refer to the related description of S410 in the above-mentioned portion of the embodiment of the present application, and are not described herein again.

S730, receive the first detection signal sent by the second device through the first antenna of the current channel detection.

It should be noted that, S730 is similar to S420, and reference may be made to the related description of S420, which is not described herein again.

S740, extracting channel characteristic parameters of the first sounding signal.

It should be noted that S740 is similar to S430, and reference may be made to the related description of S430, which is not described herein again.

And S750, entering next channel detection under the condition that the preset detection end condition is not met.

It should be noted that S750 is similar to S440, and reference may be made to the related description of S440, which is not repeated herein.

S760, ending the channel sounding until a preset sounding ending condition is reached, and obtaining channel characteristic parameters of the first sounding signals.

It should be noted that S760 is similar to S450, and reference may be made to the related description of S450, which is not repeated herein.

S770, a first physical layer key is generated based on the channel characteristic parameters of the plurality of first probe signals.

It should be noted that S770 is similar to S460, and reference may be made to the related description of S460, which is not repeated herein.

The secret key generation method based on the communication system provided by the embodiment of the application can perform antenna switching on the first antenna of the previous channel detection in each channel detection process to obtain the first antenna of the current channel detection, receive the first detection signal sent by the second device by using the first antenna of the current channel detection, and extract the channel characteristic parameter of the first detection signal. And generating a first physical layer key by using the channel characteristic parameters of a plurality of first detection signals acquired in the process of channel detection for a plurality of times under the condition that a preset detection end condition is reached. The first antenna is switched in any two adjacent channel detection processes, so that the space variable characteristic of a wireless channel can be introduced between the acquired channel characteristic parameters of the first detection signals. And when the preset detection ending condition is not met, entering next channel detection, acquiring the first detection signal again by using the first antenna during the next channel detection and extracting the channel characteristic parameter of the first detection signal, so that the channel characteristic parameter of the first detection signal can be acquired again after a certain time interval to introduce the time-varying characteristic of the wireless channel among the acquired channel characteristic parameters of the plurality of first detection signals. Therefore, according to the secret key generation method based on the communication system, the space variable characteristic and the time variable characteristic of the wireless channel are introduced between the channel characteristic parameters of the acquired first detection signals, so that the safety of the secret key is improved, and the safety of the wireless network is further improved.

And, it should be further noted that, through the above steps S710 to S770, when the signal attenuation between the first device and the second device is within the preset value range, that is, when the first device and the second device are in a slow fading environment, the variable quantity of the channel characteristic parameter of the first detection signal may be increased by introducing the space variable characteristic and the time varying characteristic of the wireless channel in a manner of switching the antenna and performing the next channel detection at a certain time interval during the acquisition process of the channel characteristic parameter in the slow fading environment, so as to avoid the problem that the first physical layer key is all 0 or all 1 due to the small change of the wireless channel characteristic in the slow fading environment, improve the random fading of the physical layer key in the low fading environment, and improve the security of the wireless communication.

In some embodiments, the key generation method based on the communication system may further include step F2 and step F3 after S710.

Step F2, when the signal attenuation is outside the preset value range, in each channel detection, receiving a second detection signal sent by the second device through a preset second antenna, and extracting a channel characteristic parameter of the received second detection signal until reaching a preset detection end condition, thereby obtaining channel characteristic parameters of a plurality of second detection signals.

In step F2, in a plurality of channel sounding procedures, a second sounding signal may be received through the same second antenna. For example, if the preset value range is a range with 0 as a lower limit value and a first preset attenuation threshold value as an upper limit value, the second detection signal sent by the second device may be received through the second antenna of the advanced device when the signal attenuation is greater than the first preset attenuation threshold value.

In one example, a second sounding signal transmitted by a second device may be received on the same channel using a second antenna during multiple channel sounding procedures.

Exemplarily, fig. 8 shows a switching schematic diagram of a second antenna provided in an embodiment of the present application. If the first device comprises antennas 1-3, as shown in fig. 8, antenna 1 may be used as the second antenna.

Correspondingly, the same antenna can be used during the first channel detection and the nth channel detection, that is, the antenna 1 receives the first detection signal sent by the second device through the channel 1.

For example, taking the antenna switching strategy shown in fig. 8 as an example, if channel detection is performed 3 times in 4 rounds and each round for a total of 12 times, a matrix generated by the channel characteristic parameters in the 12 channel detection processes may be represented as the following matrix:

wherein any element in the matrix

And the channel characteristic parameters of the second detection signals received by the first equipment through the second antenna on the channel with the channel number g are shown in the y-th channel detection of the x-th round. Wherein x is any positive integer less than or equal to 4, y is any positive integer less than or equal to 3, and g is 1.

By the example, when the signal attenuation is sufficient, the key randomness can be ensured by introducing the time-varying characteristic among the channel characteristic parameters of the acquired multiple first detection signals, the influence of the processes of antenna switching, channel adjustment and the like on the key consistency of both communication parties is avoided, the efficiency of generating the whole key is improved, and the key randomness, the key consistency and the whole generation efficiency are considered.

In another example, a second sounding signal transmitted by a second device may be received on a different channel using a second antenna during multiple channel sounding procedures.

Exemplarily, fig. 9 shows a switching schematic diagram of another second antenna provided in an embodiment of the present application. If the first device comprises antennas 1-3, as shown in fig. 9, antenna 1 may be used as the second antenna.

Accordingly, fig. 8 and 9 differ in that communication may be on channel 1 for the first channel sounding and on channel 3 for the second channel sounding, … …, and on channel 5 for the nth channel sounding.

For example, taking the antenna switching strategy shown in fig. 9 as an example, if channel detection is performed 3 times in 4 rounds and each round for a total of 12 times, a matrix generated by the channel characteristic parameters in the 12 channel detection processes may be represented as the following matrix:

wherein any element in the matrix

And the channel characteristic parameters of the second detection signals received by the first equipment through the second antenna on the channel with the channel number g are shown in the y-th channel detection of the x-th round. Wherein x is any positive integer less than or equal to 4, y is any positive integer less than or equal to 3, and g is 1, 3, or 5.

By the example, frequency-dependent characteristics can be introduced among the acquired channel characteristic parameters of the plurality of first detection signals, so that the randomness of the key can be ensured, and the randomness of the key can be further improved.

In yet another example, step F2 may include step F21 and step F22.

In step F21, when the signal attenuation is greater than the first preset attenuation threshold and less than or equal to the second preset attenuation threshold, a second detection signal sent by the second device may be received through the second antenna on different channels during multiple channel detections. And the second preset attenuation threshold is larger than the first preset attenuation threshold. It should be noted that the second preset attenuation threshold may be set according to actual conditions and specific requirements, which is not described herein again.

It should be noted that, for a specific process of step F21, reference may be made to the above-mentioned part of the embodiment of the present application in conjunction with the relevant description of fig. 9, and details are not described herein again.

In step F22, when the signal attenuation is greater than the second preset attenuation threshold, the second detection signal sent by the second device may be received through the second antenna on the same channel during multiple times of channel detection.

It should be noted that, for a specific process of step F22, reference may be made to the above-mentioned part of the embodiment of the present application in conjunction with the relevant description of fig. 8, and details are not described herein again.

By the example, in the receiving process of the second detection signal, the signal transmission channel can be flexibly adjusted according to the signal attenuation, so that the consistency of the key and the efficiency of key generation can be considered when the signal attenuation is enough to ensure the randomness of the key.

Step F3, generating a second physical layer key according to the channel characteristic parameters of the plurality of second probe signals.

It should be noted that, for specific content of generating the second physical layer key, reference may be made to the related description of generating the first physical layer key in the above-mentioned part of the embodiment of the present application, and details of the description are not repeated here.

Optionally, to facilitate two-way communication, during each detection, the first device may further send a fourth detection signal to the second device through the second antenna, so that the second device generates a fourth physical layer key corresponding to the second physical layer key based on the channel characteristic parameters of the fourth detection signal during multiple channel detections.

It should be noted that specific contents of the fourth physical layer key may refer to the related description of the third physical layer key in the above-mentioned portion of the embodiment of the present application, and are not described herein again.

It should be noted that, in each channel sounding, the fourth sounding signal may be sent before the second sounding signal, or may be sent after the second sounding signal, or both of them may be sent simultaneously, which is not limited in particular.

Based on the same inventive concept, the embodiment of the present application further provides a key generation method based on a communication system, and the method may be performed by the second device shown in fig. 1 to fig. 3. Next, the key generation method by the communication system will be described with reference to fig. 10.

Fig. 10 shows a flowchart of another method for generating a key based on a communication system in this embodiment of the present application, and as shown in fig. 10, the method for generating a key based on a communication system in this embodiment of the present application includes the following steps S1010 to S1030.

S1010, in the current channel detection, a first detection signal is sent to a first antenna of the first device in the current channel detection, so that the first device extracts a channel characteristic parameter of the first detection signal after receiving the first detection signal. The first antenna of the current channel detection is obtained by switching the antennas of the first antenna of the previous channel detection among the plurality of antennas.

It should be noted that, reference may be made to the relevant description of S410 to S430 in the above-mentioned part of the embodiment of the present application for S1010, which is not described herein again.

In one example, the second device may receive the first sounding signal through the same antenna in multiple channel sounding procedures.

In another example, in a case that the second device is a multi-antenna device, the second device may perform antenna switching on a transmitting/receiving antenna of a previous channel sounding, obtain a transmitting/receiving antenna of the current channel sounding, and receive the first sounding signal of the current channel sounding by using the transmitting/receiving antenna.

And S1020, entering next channel detection under the condition that the preset detection ending condition is not met.

It should be noted that, in S1020, reference may be made to the relevant description of S440 in the foregoing part of the embodiment of the present application, and details are not repeated here.

S1030, ending the channel sounding until a preset sounding ending condition is met, so that the first device obtains channel characteristic parameters of the multiple first sounding signals after ending the channel sounding, and generating a first physical layer key based on the channel characteristic parameters of the multiple first sounding signals.

It should be noted that, reference may be made to the relevant description of S450 and S460 in the above section of the embodiment of the present application for S1030, and details are not described here again.

In the key generation method based on the communication system provided in the embodiment of the present application, the second device may send the first probe signal to the first antenna of the first device in the current communication process, so that the first device may extract the channel characteristic parameter of the first probe signal, and generate the first physical layer key by using the channel characteristic parameters of the plurality of first probe signals acquired in the channel detection processes for a plurality of times when the preset detection end condition is reached. Because the first antenna of the first device is switched in any two adjacent channel detection processes, the space variable characteristic of the wireless channel can be introduced between the channel characteristic parameters of the obtained multiple first detection signals. And when the preset detection ending condition is not met, entering next channel detection, acquiring the first detection signal again by using the first antenna during the next channel detection and extracting the channel characteristic parameter of the first detection signal, so that the channel characteristic parameter of the first detection signal can be acquired again after a certain time interval to introduce the time-varying characteristic of the wireless channel among the acquired channel characteristic parameters of the plurality of first detection signals. Therefore, the space variable characteristic and the time-varying characteristic of the wireless channel are introduced between the channel characteristic parameters of the acquired plurality of first detection signals, so that the security of the secret key is improved, and the security of the wireless network is further improved.

In some embodiments, during the current channel sounding, the second device may further receive a third sounding signal sent by the first device through the first antenna of the current channel sounding, and extract a channel characteristic parameter of the third sounding signal. And after finishing the channel detection, generating a third physical layer key by using the respective channel characteristic parameters of the third detection signals of the plurality of times of channel detection.

For the generation process of the third physical layer key, reference may be made to the relevant description of the above-mentioned part of the embodiment of the present application, which is not described herein again.

In some embodiments, the second device may return the third probe signal to the first device based on the same channel if the first probe signal was sent to the first device after receiving the third probe signal.

In other embodiments, if the first probe signal is sent before the third probe signal, the second device may send the first probe signal after performing signal switching according to the channel switching method provided in the above-mentioned portion of this embodiment, so that the first device may return the third probe signal based on the same channel after receiving the first probe signal.

It should be noted that, when the second device has multiple antennas, the execution steps of the second device in each communication process may be similar to those of the first device, for example, switching antennas, and the like, which is not described again.

Based on the same inventive concept, the embodiment of the present application further provides a first device, such as the following embodiments.

Fig. 11 shows a schematic structural diagram of a first device in an embodiment of the present application, and as shown in fig. 11, the first device 1100 includes: an antenna switching module 1110, a signal receiving module 1120, a parameter extracting module 1130, a processing module 1140, and a first key generating module 1150.

The antenna switching module 1110 is configured to, during this channel detection, perform antenna switching on a first antenna of a previous channel detection among multiple antennas to obtain a first antenna of this channel detection.

The signal receiving module 1120 is configured to receive, through the first antenna for channel sounding, the first sounding signal sent by the second device.

The parameter extraction module 1130 is configured to extract a channel characteristic parameter of the first probe signal.

The processing module 1140 is configured to enter next channel detection until a preset detection end condition is reached, and end the channel detection to obtain channel characteristic parameters of a plurality of first detection signals.

A first key generation module 1150, configured to generate a first physical layer key based on channel characteristic parameters of the plurality of first sounding signals.

In some embodiments, the first device 1100 further comprises an operating mode determination module.

And the working mode determining module is used for determining the working mode of the first equipment and the working mode of the second equipment.

Accordingly, the antenna switching module 1110 includes: a first switching unit.

The first switching unit is configured to select a first antenna for channel detection this time from at least one antenna whose antenna number interval with a first antenna for channel detection last time is greater than a preset number threshold value when at least one of the operating mode of the first device and the operating mode of the second device is a preset operating mode.

In some embodiments, the antenna switching module 1110 further comprises: and a second switching unit.

And the second switching unit is used for selecting the first antenna for the current channel detection from at least one antenna, the distance between the first antenna and the number of antennas of the first antenna for the previous channel detection is less than or equal to a preset number threshold, under the condition that the working mode of the first device and the working mode of the second device are not the preset working mode.

In some embodiments, the first device 1100 further comprises: and an attenuation amount determining module.

And the attenuation amount determining module is used for determining the signal attenuation amount between the first device and the second device.

Accordingly, the antenna switching module 1110 includes: and a third switching unit.

And the third switching unit is used for switching the antennas of the first antenna of the previous channel detection in the plurality of antennas under the condition that the signal attenuation is within the preset value range, so as to obtain the first antenna of the current channel detection.

In some embodiments, the first device 1100 further comprises: the device comprises a signal detection module and a second key generation module.

And the signal detection module is used for receiving a second detection signal sent by second equipment through a preset second antenna and extracting the channel characteristic parameters of the received second detection signal until a preset detection end condition is reached under the condition that the signal attenuation is out of a preset value range and during each channel detection, so as to obtain the channel characteristic parameters of a plurality of second detection signals.

And the second key generation module is used for generating a second physical layer key according to the channel characteristic parameters of the plurality of second detection signals.

In some embodiments, the first device 1100 further comprises: and a channel selection module.

The channel selection module is used for selecting a channel of the current channel detection from other channels except the channel of the previous channel detection in a plurality of channels of a preset channel set;

accordingly, the signal receiving module 1120 is specifically configured to: receiving a first detection signal sent by the second device through the channel detected this time through the first antenna detected this time,

the plurality of channels of the preset channel set correspond to different sub-frequency bands of the preset working frequency band.

In some embodiments, the number of each channel in the plurality of channels is an ordering result of the frequencies of the sub-bands corresponding to each channel in the plurality of channels.

A channel selection module comprising: the device comprises a channel number determining unit, a number adjusting unit, a first channel determining unit and a second channel determining unit.

And the channel number determining unit is used for determining the channel number of the channel detected at the previous time.

And the number adjusting unit is used for increasing the signal number by a preset integer to obtain the increased channel number.

And a first channel determining unit, configured to determine, when the increased channel number is less than or equal to the maximum value of the channel number, a channel corresponding to the increased channel number as a channel of the current channel sounding.

And the second channel determining unit is used for taking the channel corresponding to the initial channel number as the channel detected at the current time when the increased channel number is greater than the maximum value.

In some embodiments, the first device 1100 further comprises: and a signal sending module.

And the signal sending module is used for sending a third detection signal to the second equipment through the first antenna for each channel detection so as to enable the second equipment to extract the channel characteristic parameters of the third detection signal for each channel detection and generate a third physical layer key corresponding to the first physical layer key according to the channel characteristic parameters of the third detection signal for multiple channel detections.

In some embodiments, the first key generation module 1150 includes: a parameter quantization unit and a key negotiation unit.

And the parameter quantization unit is used for quantizing the channel characteristic parameters of the plurality of first detection signals to obtain a first bit sequence.

And the key negotiation unit is used for performing key negotiation by using the first bit sequence and the second bit sequence to obtain a first physical layer key, wherein the second bit sequence is obtained by quantizing the channel characteristic parameters of a third detection signal of the second device, which is detected by multiple channels.

In some embodiments, the first device 1100 further comprises: a time interval determination unit, a correlation judgment unit and a valid signal determination unit.

A time interval determining unit, configured to determine, for each first sounding signal, a transmission time interval between the first sounding signal and an associated third sounding signal, where the associated third sounding signal and each first sounding signal belong to the same channel sounding.

And the correlation judging unit is used for judging whether the transmission time interval is larger than the preset channel correlation time.

And the effective signal determining unit is used for determining that the first detection signal is effective under the condition that the transmission time interval is less than or equal to the preset channel correlation time.

Correspondingly, the parameter quantization unit is specifically configured to: and quantizing the channel characteristic parameters of the effective first detection signals in the plurality of first detection signals to obtain a first bit sequence.

The first device provided in the embodiment of the present application may perform antenna switching on a first antenna of previous channel detection in each channel detection process to obtain the first antenna of this channel detection, receive a first detection signal sent by a second device by using the first antenna of this channel detection, and extract a channel characteristic parameter of the first detection signal. And generating a first physical layer key by using the channel characteristic parameters of a plurality of first detection signals acquired in the process of channel detection for a plurality of times under the condition that a preset detection end condition is reached. The first antenna is switched in any two adjacent channel detection processes, so that the space variable characteristic of a wireless channel can be introduced between the acquired channel characteristic parameters of the first detection signals. And when the preset detection ending condition is not met, entering next channel detection, acquiring the first detection signal again by using the first antenna during the next channel detection and extracting the channel characteristic parameter of the first detection signal, so that the channel characteristic parameter of the first detection signal can be acquired again after a certain time interval to introduce the time-varying characteristic of the wireless channel among the acquired channel characteristic parameters of the plurality of first detection signals. Therefore, according to the secret key generation method based on the communication system, the space variable characteristic and the time variable characteristic of the wireless channel are introduced between the channel characteristic parameters of the acquired first detection signals, so that the safety of the secret key is improved, and the safety of the wireless network is further improved.

It should be noted that the first device 1100 shown in fig. 11 may perform each step in the method embodiment shown in fig. 4 to 9, and implement each process and effect in the method embodiment shown in fig. 4 to 9, which are not described herein again.

Based on the same inventive concept, a second apparatus is also provided in the embodiments of the present application, as in the following embodiments.

Fig. 12 shows a schematic structural diagram of a second apparatus in an embodiment of the present application, and as shown in fig. 12, the second apparatus 1200 includes: an antenna switching module 1110, a signal receiving module 1120, a parameter extracting module 1130, a processing module 1140, and a first key generating module 1150.

A signal sending module 1210, configured to send, during the current channel detection, a first detection signal to a first antenna of the first device for the current channel detection, so that the first device extracts a channel characteristic parameter of the first detection signal after receiving the first detection signal, where the first antenna of the current channel detection is obtained by antenna switching of a first antenna of a previous channel detection among multiple antennas;

the detection processing module 1220 is configured to enter next channel detection until the preset detection end condition is reached, end the channel detection, so that the first device obtains channel characteristic parameters of the plurality of first detection signals after ending the channel detection, and generate the first physical layer key based on the channel characteristic parameters of the plurality of first detection signals.

The second device provided in this embodiment of the present application may send the first probe signal to the first antenna of the first device in the communication process of this time, so that the first device may extract the channel characteristic parameter of the first probe signal, and generate the first physical layer key by using the channel characteristic parameters of the plurality of first probe signals obtained in the channel probing processes of multiple times when the preset probing end condition is reached. Because the first antenna of the first device is switched in any two adjacent channel detection processes, the space variable characteristic of the wireless channel can be introduced between the channel characteristic parameters of the obtained multiple first detection signals. And when the preset detection ending condition is not met, entering next channel detection, acquiring the first detection signal again by using the first antenna during the next channel detection and extracting the channel characteristic parameter of the first detection signal, so that the channel characteristic parameter of the first detection signal can be acquired again after a certain time interval to introduce the time-varying characteristic of the wireless channel among the acquired channel characteristic parameters of the plurality of first detection signals. Therefore, the space variable characteristic and the time variable characteristic of the wireless channel are introduced between the acquired channel characteristic parameters of the plurality of first detection signals, so that the security of the secret key is improved, and the security of the wireless network is further improved.

In some embodiments, the second device 1200 may further include a signal receiving module and a key generating module.

The signal receiving module is configured to receive a third probe signal sent by the first device, and the key generating module is configured to generate a third physical layer key based on a channel characteristic parameter of the third probe signal obtained through multiple channel probes.

It should be noted that, for specific contents of the signal receiving module and the key generating module, reference may be made to the relevant description of the above-mentioned part of the embodiment of the present application in conjunction with fig. 11, and details are not repeated here.

In some embodiments, the second device 1200 may be a multi-antenna device, and when the second device is a multi-antenna device, the second device may further include an antenna switching module, and specific content of the antenna switching module may refer to relevant description in the embodiment of the present application in combination with fig. 11, which is not described again here.

In some embodiments, the second device 1200 may further include a channel selection module, and specific content thereof may refer to the related description of the above section in conjunction with fig. 11 in this embodiment, which is not described herein again.

In some embodiments, the second device 1200 may further include a time interval determining unit, a correlation determining unit, and a valid signal determining unit to determine whether the third detection signal is valid, for which specific contents may refer to the related description in the foregoing section of this embodiment in conjunction with fig. 11, and are not described herein again.

It should be noted that the second device 1200 shown in fig. 12 may perform each step in the method embodiment shown in fig. 10, and implement each process and effect in the method embodiment shown in fig. 10, which is not described herein again.

Based on the same inventive concept, the embodiment of the application also provides a communication system. With continued reference to fig. 1, a communication system may include: a first device 110, and a second device 120.

It should be noted that, for specific contents of the first device and the second device, reference may be made to the above-mentioned part of the embodiment of the present application in conjunction with the relevant description of fig. 11 and fig. 12, which is not described again.

In one example, fig. 13 is a logic diagram illustrating a key generation process based on a communication system according to an embodiment of the present application.

As shown in fig. 13, in the key generation process, the first device and the second device may periodically perform channel sounding for multiple times, and in the case of ensuring that the first sounding signal sent by the second device 130 to the first device 110 and the third sounding signal sent by the first device 110 to the second device 130 are within a relevant time (within a preset channel relevant time) in each channel sounding process, the first antenna of the first device and the channel between the first device 110 and the second device 120 may be switched in each channel sounding process, so that the first device 110 may acquire the channel characteristic parameters of the multiple first sounding signals in a periodic, multi-channel, multi-antenna manner, and the second device 120 may acquire the channel characteristic parameters of the multiple third sounding signals in a periodic, multi-channel, multi-antenna manner.

The first device 110 quantizes the obtained channel characteristic parameters to obtain a first bit sequence. And, the second device 120 quantizes the obtained channel characteristic parameters to obtain a second bit sequence.

The first device 110 and the second device 120 perform key agreement on the first bit sequence and the second bit sequence. Illustratively, after the first device 110 and the second device 120 perform the consistency check and key enhancement on the first bit sequence and the second bit sequence, the first device 110 generates a first physical layer key, and the second device 120 correspondingly generates a third physical layer key.

After obtaining the first physical layer key and the third physical layer key, first device 110 and second device 120 may perform encrypted communication based on the first physical layer key and the third physical layer key.

It should be noted that, for the channel characteristic parameters of the plurality of first probe signals and the channel characteristic parameters of the plurality of third probe signals, since the characteristic parameters may be obtained in a periodic, multi-channel, and multi-antenna manner, sufficient time-varying characteristics, frequency-varying characteristics, and space-varying characteristics may be introduced between the channel characteristic parameters, thereby ensuring randomness of the physical layer keys generated at both ends of the first device 110 and the second device 120, and further increasing security of wireless communication.

As will be appreciated by one skilled in the art, aspects of the present application may be embodied as a system, method or program product. Accordingly, various aspects of the present application may be embodied in the form of: an entirely hardware embodiment, an entirely software embodiment (including firmware, microcode, etc.), or an embodiment combining hardware and software aspects that may all generally be referred to herein as a "circuit," module "or" system.

An electronic device 1400 according to this embodiment of the present application is described below with reference to fig. 14. The electronic device 1400 shown in fig. 14 is only an example, and should not bring any limitation to the functions and the scope of use of the embodiments of the present application.

As shown in fig. 14, electronic device 1400 is in the form of a general purpose computing device. The components of the electronic device 1400 may include, but are not limited to: the at least one processing unit 1410, the at least one memory unit 1420, and the bus 1430 that couples the various system components including the memory unit 1420 and the processing unit 1410.

Where the storage unit stores program code, the program code may be executed by processing unit 1410 such that processing unit 1410 performs steps according to various exemplary embodiments of the present application described in the "exemplary methods" section above in this specification.

The storage unit 1420 may include readable media in the form of volatile memory units, such as a random access memory unit (RAM)14201 and/or a cache memory unit 14202, and may further include a read only memory unit (ROM) 14203.

Storage unit 1420 may also include a program/utility 14204 having a set (at least one) of program modules 14205, such program modules 14205 including but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which, or some combination thereof, may comprise an implementation of a network environment.

Bus 1430 may be any type of bus structure including a memory cell bus or memory cell controller, a peripheral bus, an accelerated graphics port, a processing unit, or a local bus using any of a variety of bus architectures.

The electronic device 1400 may also communicate with one or more external devices 1440 (e.g., keyboard, pointing device, bluetooth device, etc.), with one or more devices that enable a user to interact with the electronic device 1400, and/or with any devices (e.g., router, modem, etc.) that enable the electronic device 1400 to communicate with one or more other computing devices. Such communication can occur over an input/output (I/O) interface 1450.

Also, the electronic device 1400 may communicate with one or more networks (e.g., a Local Area Network (LAN), a Wide Area Network (WAN), and/or a public network, such as the internet) via the network adapter 1460.

As shown in FIG. 14, the network adapter 1460 communicates with the other modules of the electronic device 1400 via the bus 1430.

It should be appreciated that although not shown in the figures, other hardware and/or software modules may be used in conjunction with the electronic device 1400, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems, among others.

Through the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein may be implemented by software, or by software in combination with necessary hardware. Therefore, the technical solution according to the embodiments of the present application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a usb disk, a removable hard disk, etc.) or on a network, and includes several instructions to make a computing device (which can be a personal computer, a server, a terminal device, or a network device, etc.) execute the method according to the embodiments of the present application.

In an exemplary embodiment of the present application, there is also provided a computer-readable storage medium, which may be a readable signal medium or a readable storage medium. On which a program product capable of implementing the method of the present application is stored.

In some possible embodiments, various aspects of the present application may also be implemented in the form of a program product comprising program code for causing a terminal device to perform the steps according to various exemplary embodiments of the present application described in the above-mentioned "exemplary methods" section of this specification, when the program product is run on the terminal device.

More specific examples of the computer-readable storage medium in the present application may include, but are not limited to: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

In the present application, a computer readable storage medium may include a propagated data signal with readable program code embodied therein, either in baseband or as part of a carrier wave.

Such a propagated data signal may take many forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof.

A readable signal medium may also be any readable medium that is not a readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

In some examples, program code embodied on a computer readable storage medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

In particular implementations, program code for carrying out operations of the present application may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, C + +, or the like, as well as conventional procedural programming languages, such as the "C" programming language or similar programming languages.

The program code may execute entirely on the user's computing device, partly on the user's device, as a stand-alone software package, partly on the user's computing device and partly on a remote computing device, or entirely on the remote computing device or server.

In the case of a remote computing device, the remote computing device may be connected to the user computing device through any kind of network, including a Local Area Network (LAN) or a Wide Area Network (WAN), or may be connected to an external computing device (e.g., through the internet using an internet service provider).

It should be noted that although in the above detailed description several modules or units of the device for action execution are mentioned, such a division is not mandatory.

Indeed, the features and functionality of two or more modules or units described above may be embodied in one module or unit, according to embodiments of the application. Conversely, the features and functions of one module or unit described above may be further divided into embodiments by a plurality of modules or units.

Moreover, although the steps of the methods in this application are depicted in the drawings in a particular order, this does not require or imply that these steps must be performed in this particular order, or that all of the depicted steps must be performed, to achieve desirable results. Additionally or alternatively, certain steps may be omitted, multiple steps combined into one step execution, and/or one step broken down into multiple step executions, etc.

Through the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein may be implemented by software, or by software in combination with necessary hardware.

Therefore, the technical solution according to the embodiments of the present application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a usb disk, a removable hard disk, etc.) or on a network, and includes several instructions to enable a computing device (which can be a personal computer, a server, a mobile terminal, or a network device, etc.) to execute the method according to the embodiments of the present application.

Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein.

This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.

Claims

1. A key generation method based on a communication system, wherein the communication system includes a first device and a second device, the first device includes a plurality of antennas, and the method is applied to the first device, and the method includes:

during the channel detection, in the multiple antennas, performing antenna switching on a first antenna of the previous channel detection to obtain a first antenna of the channel detection;

receiving a first detection signal sent by the second device through a first antenna of the channel detection;

extracting channel characteristic parameters of the first detection signal;

under the condition that a preset detection ending condition is not reached, entering next channel detection, and ending the channel detection until the preset detection ending condition is reached to obtain channel characteristic parameters of a plurality of first detection signals;

generating a first physical layer key based on channel characteristic parameters of the plurality of first sounding signals.

2. The method according to claim 1, wherein before performing antenna switching on a first antenna of a previous channel sounding among the plurality of antennas to obtain a first antenna of a current channel sounding, the method comprises:

determining an operating mode of the first device and an operating mode of the second device;

the antenna switching is performed on a first antenna of a previous channel detection among the plurality of antennas to obtain the first antenna of the current channel detection, including:

under the condition that at least one of the working mode of the first device and the working mode of the second device is a preset working mode, selecting a first antenna for the current channel detection from at least one antenna, the number of which is more than a preset number threshold, away from the antenna number of the first antenna for the previous channel detection;

3. The method according to claim 2, wherein the performing antenna switching on a first antenna of a previous channel sounding among the plurality of antennas to obtain a first antenna of the current channel sounding further includes:

and under the condition that the working mode of the first device and the working mode of the second device are not the preset working mode, selecting the first antenna for the current channel detection from at least one antenna, wherein the interval between the number of the antennas of the first antenna for the previous channel detection and the number of the antennas of the first antenna for the previous channel detection is less than or equal to a preset number threshold.

4. The method according to claim 1, wherein before performing antenna switching on a first antenna of a previous channel sounding among the plurality of antennas to obtain a first antenna of a current channel sounding, the method further comprises:

5. The method of claim 4, wherein after determining the amount of signal attenuation between the first device and the second device, the method further comprises:

under the condition that the signal attenuation is out of the preset value range, receiving a second detection signal sent by the second equipment through a preset second antenna during each channel detection, and extracting channel characteristic parameters of the received second detection signal until the preset detection end condition is reached to obtain channel characteristic parameters of a plurality of second detection signals;

6. The method according to claim 1, wherein before receiving the first sounding signal transmitted by the second device through the first antenna of the present channel sounding, the method further comprises:

the receiving, by the first antenna for channel sounding of this time, the first sounding signal sent by the second device includes:

wherein the plurality of channels of the preset channel set correspond to different sub-bands of a preset working band.

7. The method according to claim 6, wherein the number of each of the plurality of channels is an ordering result of the frequencies of the sub-bands corresponding to each of the plurality of channels in the plurality of channels;

the selecting, from the plurality of channels in the preset channel set, a channel for channel sounding this time from other channels except for a channel for channel sounding last time includes:

determining the channel number of the channel detected by the previous channel;

and taking the channel corresponding to the initial channel number as the channel of the current channel detection under the condition that the increased channel number is greater than the maximum value.

8. The method of claim 1, further comprising:

and during each channel detection, sending a third detection signal to the second device through the first antenna of each channel detection, so that the second device extracts the channel characteristic parameters of the third detection signal of each channel detection, and generates a third physical layer key corresponding to the first physical layer key according to the channel characteristic parameters of the third detection signal of multiple channel detections.

9. The method of claim 8, wherein the generating a first physical layer key based on the channel characteristic parameters of the first sounding signals comprises:

and performing key agreement by using the first bit sequence and a second bit sequence to obtain a first physical layer key, wherein the second bit sequence is obtained by quantizing channel characteristic parameters of a third detection signal of the second device, which is detected by the multiple channels.

10. The method of claim 8, wherein before quantizing the channel characteristic parameters of the first sounding reference signals to obtain the first bit sequence, the method further comprises:

determining, for each first sounding signal, a transmission time interval of the first sounding signal and an associated third sounding signal, wherein the associated third sounding signal and the each first sounding signal belong to the same channel sounding;

judging whether the transmission time interval is greater than the relevant time of a preset channel;

determining that the first sounding signal is valid if the transmission time interval is less than or equal to the preset channel correlation time;

the quantizing the channel characteristic parameters of the plurality of first detection signals to obtain a first bit sequence includes:

and quantizing the channel characteristic parameters of the effective first detection signals in the plurality of first detection signals to obtain the first bit sequence.

11. A key generation method based on a communication system, wherein the communication system includes a first device and a second device, the first device includes a plurality of antennas, and the method is applied to the second device, and the method includes:

during the current channel detection, sending a first detection signal to a first antenna of the current channel detection of the first device, so that the first device extracts a channel characteristic parameter of the first detection signal after receiving the first detection signal, wherein the first antenna of the current channel detection is obtained by antenna switching of the first antenna of the previous channel detection among the multiple antennas;

and under the condition that a preset detection ending condition is not reached, entering next channel detection until the preset detection ending condition is reached, ending the channel detection so that the first equipment obtains channel characteristic parameters of a plurality of first detection signals after ending the channel detection, and generating a first physical layer key based on the channel characteristic parameters of the plurality of first detection signals.

12. A first device, wherein the first device and the second device belong to a communication system, wherein the first device comprises a plurality of antennas, and wherein the first device comprises:

a signal receiving module, configured to receive, through the first antenna of the channel detection, a first detection signal sent by the second device;

a parameter extraction module, configured to extract a channel characteristic parameter of the first probe signal;

the processing module is used for entering next channel detection under the condition that a preset detection ending condition is not reached, ending the channel detection until the preset detection ending condition is reached, and obtaining channel characteristic parameters of a plurality of first detection signals;

a first key generation module, configured to generate a first physical layer key based on the channel characteristic parameters of the first sounding signals.

13. A second device, wherein the second device and a first device belong to a communication system, wherein the first device comprises a plurality of antennas, and wherein the second device comprises:

a signal sending module, configured to send, during current channel detection, a first detection signal to a first antenna of the first device for the current channel detection, so that the first device extracts a channel characteristic parameter of the first detection signal after receiving the first detection signal, where the first antenna of the current channel detection is obtained after antenna switching is performed on the first antenna of previous channel detection among the multiple antennas;

the detection processing module is used for entering next channel detection under the condition that a preset detection end condition is not reached, ending the channel detection until the preset detection end condition is reached, so that the first equipment obtains channel characteristic parameters of a plurality of first detection signals after the channel detection is ended, and generating a first physical layer key based on the channel characteristic parameters of the plurality of first detection signals.

14. A communication system, comprising:

the first device of claim 12; and the combination of (a) and (b),

the second device of claim 13.

15. An electronic device, comprising:

a processor; and

a memory for storing executable instructions of the processor;

wherein the processor is configured to perform the communication system based key generation method of any of claims 1-11 via execution of the executable instructions.

16. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out a method for key generation based on a communication system according to any one of claims 1 to 11.