CN114205073B - Password Reverse Firewall and Its Security Defense Method - Google Patents

Abstract

The invention discloses a password reverse firewall and a security defense method thereof, wherein the password reverse firewall includes a first password reverse firewall and a second password reverse firewall, and each password reverse firewall is used to link entities and external information The method includes the following steps: performing random number extraction on the first public key to obtain the first random number; performing public key re-randomization processing on the first public key according to the first random number to obtain the second public key; random number extraction is performed on the first ciphertext to obtain a second random number, and ciphertext re-randomization is performed on the first ciphertext according to the second random number to obtain the second ciphertext; according to the first random number pair The second ciphertext is processed to obtain a third ciphertext. As a result, the number of random numbers generated during the operation of the password reverse firewall is effectively reduced, the degree of dependence on trusted random sources is reduced, and the realizability is improved.

Description

Password Reverse Firewall and Its Security Defense Method

technical field

The invention relates to the field of cryptography, in particular to a security defense method of a password reverse firewall and a password reverse firewall.

Background technique

After a series of security incidents represented by "Prism Gate", the issue of mass surveillance has attracted extensive attention from the field of cryptography theory and information security industry. As one of the important possible means of mass surveillance, subversion attack (Subversion attack) has been discussed in the academic circle because of its high concealment and extensive harm. Monitors can use special powers and means to replace (subvert) the execution of the cryptographic algorithm used by the user at various stages of cryptographic system construction and application, making it different from the standard algorithm description to a certain extent, thereby realizing protection of user privacy. of acquisition. In some special cases, for users who do not have special backdoor information, the subverted algorithm execution and standard algorithm description even have theoretical computational unrecognizable characteristics, which makes it quite difficult to defend against subversion attacks.

Cryptographic reverse firewall (CRF) is one of the effective means against subversive attacks. As a trusted device, it can exist in various forms between the user's computer and the outside world, and process all the information entering and leaving the computer in the cryptographic protocol, so as to prevent the user's privacy from being leaked. However, the existing cryptographic reverse firewalls only consider the form of a CRF defending against an entity in a protocol when designing, and the CRF entity constructed directly according to this design does not have expandable and combinable capabilities in theory. ability. Moreover, if this design is adopted, a large number of CRFs need to be set in practical applications. Considering the background of large-scale surveillance, deploying such a large number of trusted modules is obviously not in line with industrial reality. In addition, in the specific construction of all current CRFs, each time the protocol entity generates a random number, the CRF must regenerate a corresponding random number, that is, the CRF needs to generate a trusted random number equal to the random number generated during the protocol operation , this design needs to consume a large amount of trusted resources, and the actual feasibility is not high.

Contents of the invention

The present invention aims to solve one of the technical problems in the related art at least to a certain extent. For this reason, the first object of the present invention is to propose a security defense method of a password reverse firewall, which can effectively reduce the random number quantity generated by the password reverse firewall during operation, reduce the dependence on trusted random sources, Improve realizability.

The second object of the present invention is to propose a password reverse firewall.

In order to achieve the above purpose, the embodiment of the first aspect of the present invention proposes a security defense method for a password reverse firewall, wherein the password reverse firewall includes a first password reverse firewall and a second password reverse firewall, the The corresponding message sending entity of the first password reverse firewall is set, and the corresponding message receiving entity of the second password reverse firewall is set, and each of the password reverse firewalls includes a first port and a second port, and the first port is connected to the second port. The entity is connected, the second port is connected to an external channel, and each of the password reverse firewalls is used to process messages transmitted between the entity and the external information, and the method includes the following steps: The first port of the second password reverse firewall receives the first public key sent by the message receiving entity, and uses the internal session unit to extract a random number from the first public key to obtain a first random number, and according to the performing public key re-randomization processing on the first public key with the first random number to obtain a second public key, and sending the second public key to the external channel through a corresponding second port; the second public key A second port of a cryptographic reverse firewall receives the second public key from the external channel, uses an internal session unit to transparently transmit the second public key to the message sending entity through the corresponding first port, and Recording the second public key; the first port of the first password reverse firewall receives the first ciphertext sent by the message sending entity, and uses the internal session unit to perform a random number on the first ciphertext Extracting to obtain a second random number, performing ciphertext re-randomization on the first ciphertext according to the second random number to obtain a second ciphertext, and passing the second ciphertext through the corresponding second The port sends to the external channel; the second port of the second password reverse firewall receives the second ciphertext from the external channel, and uses the internal session unit to pair the second cipher text according to the first random number. The ciphertext is processed to obtain a third ciphertext, and the third ciphertext is transparently transmitted to the message receiving entity through the corresponding first port.

According to the security defense method of the cryptographic reverse firewall of the embodiment of the present invention, first, the first port of the second cryptographic reverse firewall receives the first public key sent from the message receiving entity, and uses the internal session unit to randomize the first public key. Number extraction to obtain the first random number, and perform public key re-randomization on the first public key according to the first random number to obtain the second public key, and send the second public key to the external channel through the corresponding second port , then, the second port of the first cryptographic reverse firewall receives the second public key from the external channel, uses the internal session unit to transparently transmit the second public key to the message sending entity through the corresponding first port, and transmits the second public key to the second public key Then, the first port of the first password reverse firewall receives the first ciphertext sent by the message sending entity, uses the internal session unit to extract the random number from the first ciphertext to obtain the second random number, and according to The second random number performs ciphertext randomization processing on the first ciphertext to obtain the second ciphertext, and sends the second ciphertext to the external channel through the corresponding second port. Finally, the second password reverses the first ciphertext of the firewall. The second port receives the second ciphertext from the external channel, uses the internal session unit to process the second ciphertext according to the first random number to obtain the third ciphertext, and sends the third ciphertext to the message through the corresponding first port Entity transparent transmission. As a result, the number of random numbers generated during the operation of the password reverse firewall is effectively reduced, the degree of dependence on trusted random sources is reduced, and the realizability is improved.

In addition, the security defense method of the password reverse firewall according to the foregoing embodiments of the present invention may also have the following additional technical features:

According to an embodiment of the present invention, the extracting the random number from the first public key to obtain the first random number includes: using a first preset injective function to encode the first public key to encode the The first public key is mapped to the input space of the first preset pseudo-random permutation function and the first encoded information is obtained; if the first encoded information already exists, an alarm is issued and all message transmissions are blocked; if the described If the first encoded information does not exist, then record the first encoded information, and use the first preset pseudo-random permutation function and the key of the first preset pseudo-random permutation function to perform the first encoding information permutation to obtain the first random number, wherein the key of the first preset pseudo-random permutation function is externally injected or automatically generated when the second password reverse firewall is started.

According to an embodiment of the present invention, performing public key re-randomization processing on the first public key according to the first random number to obtain a second public key includes: using a preset public key re-randomization function according to The first random number performs public key re-randomization processing on the first public key to obtain the second public key.

According to an embodiment of the present invention, the extracting the random number from the first ciphertext to obtain the second random number includes: using a second preset injective function to encode the first ciphertext to convert the The first ciphertext is mapped to the input space of the second preset pseudo-random permutation function and the second encoded information is obtained; if the second encoded information already exists, an alarm is issued and all message transmissions are blocked; if the described If the second coded information does not exist, then record the second coded information, and use the second preset pseudo-random permutation function and the key of the second preset pseudo-random permutation function to process the second coded information permutation to obtain the second random number, wherein the key of the second preset pseudo-random permutation function is externally injected or automatically generated when the first password reverse firewall is started.

According to an embodiment of the present invention, performing ciphertext re-randomization processing on the first ciphertext according to the second random number to obtain a second ciphertext includes: using a preset ciphertext re-randomization function according to The second random number and the second public key perform ciphertext re-randomization processing on the first ciphertext to obtain the second ciphertext.

According to an embodiment of the present invention, the processing the second ciphertext according to the first random number to obtain the third ciphertext includes: using a preset ciphertext recovery function to The second ciphertext is recovered to obtain the third ciphertext.

According to an embodiment of the present invention, the messages received and sent by the first password reverse firewall and the second password reverse firewall all satisfy the six-tuple format, and if not, an alarm reminder is given, wherein the The six-tuple format includes the protocol type identifier, session identifier, message sending entity identifier, message receiving entity identifier, message content and combined data of the message.

According to an embodiment of the present invention, the security defense method of the password reverse firewall further includes: after the second password reverse firewall receives the first public key, generates the internal session unit, and The internal session unit performs marking, wherein the marking information includes the protocol type identification, the session identification and the message receiving entity identification; after the second password reverse firewall receives the second ciphertext, it also searches Whether the internal conversational unit exists, if not, an alarm is given; if it exists, the internal conversational unit is run.

According to an embodiment of the present invention, the security defense method of the password reverse firewall further includes: after the first password reverse firewall receives the second public key, generates the internal session unit, and The internal session unit performs marking, wherein the marking information includes the protocol type identification, the session identification and the message sending entity identification; after the first password reverse firewall receives the first ciphertext, it also searches Whether the internal conversational unit exists, if not, an alarm is given; if it exists, the internal conversational unit is run.

In order to achieve the above purpose, the password reverse firewall proposed in the embodiment of the second aspect of the present invention includes the security defense method of the password reverse firewall as described above.

According to the password reverse firewall of the embodiment of the present invention, the security defense method of the above password reverse firewall can effectively reduce the number of random numbers generated by the password reverse firewall during operation, reduce the dependence on credible random sources, and improve Realizability.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Description of drawings

FIG. 1 is a schematic diagram of a deployment mode of a password reverse firewall according to an embodiment of the present invention;

Fig. 2 is a schematic diagram of the message transmission protocol principle served by the password reverse firewall according to an embodiment of the present invention;

3 is a schematic diagram of a password reverse firewall communication method according to an embodiment of the present invention

4 is a schematic flow diagram of a security defense method for a password reverse firewall according to an embodiment of the present invention;

FIG. 5 is a schematic flow diagram of a security defense method for a password reverse firewall according to an embodiment of the present invention;

6 is a schematic flow diagram of a security defense method for a password reverse firewall according to an embodiment of the present invention;

7 is a schematic flow diagram of a security defense method for a password reverse firewall according to an embodiment of the present invention;

FIG. 8 is a schematic flowchart of a security defense method for a password reverse firewall according to an embodiment of the present invention.

detailed description

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals designate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

Before introducing the password reverse firewall and the security defense method of the password reverse firewall in the embodiment of the present invention, the deployment method of the password reverse firewall in the embodiment of the present invention is described in conjunction with FIG. The principle of the message transmission protocol served by the firewall is introduced.

Specifically, as shown in Figure 1, the password reverse firewall in the embodiment of the present invention adopts a group service architecture, that is, one password reverse firewall serves multiple computers in the LAN, and has the ability to be combined, that is, when the password reverse When the number of hosts served by the firewall increases arbitrarily, the types of protocols supported by the password reverse firewall expand arbitrarily, and the calling methods and operating environments of the protocols served change arbitrarily, the security protection performance of the password reverse firewall for each protocol session is not good. decline.

Further, as shown in FIG. 2 , the message transmission protocol involved in the cryptographic reverse firewall of the embodiment of the present invention is based on the public key encryption system PE=(KeyGen, Enc, Dec), wherein, KeyGen is a key generation algorithm, and Enc is an encryption Algorithm, Dec is the decryption algorithm.

For example, in the protocol, the sender of the message is Alice, and the receiver is Bob. The initial input of the protocol is to input message m to Alice, and the final output is to output message m' to Bob, and the correctness of the protocol is reflected by m'=m, The specific way of running the protocol is as follows: First, Bob runs the key generation algorithm to generate a public-private key pair (pk, sk)←KeyGen(1 ^λ ), and sends the public key pk to Alice, the sender of the message in the protocol, and then, Alice Run c←Enc(pk, m), and send c to Bob, and finally, Bob decrypts c m′←Dec(sk, c), and outputs m′, where sk is the public key used to encrypt c The corresponding private key of the key.

The password reverse firewall and the security defense method of the password reverse firewall according to the embodiments of the present invention are described below with reference to the accompanying drawings.

Specifically, as shown in Figure 3, the password reverse firewall includes a first password reverse firewall and a second password reverse firewall, the first password reverse firewall corresponds to the message sending entity setting, and the second password reverse firewall corresponds to the message receiving entity Setting, each password reverse firewall includes a first port and a second port, the first port is connected to the entity, and the second port is connected to the external channel, and each password reverse firewall is used for transmitting between the entity and external information The message is processed.

Further, as shown in Figure 4, the security defense method of password reverse firewall comprises the following steps:

S101. The first port of the second cryptographic reverse firewall receives the first public key sent by the message receiving entity, uses the internal session unit to perform random number extraction on the first public key to obtain the first random number, and based on the first random number Perform public key re-randomization processing on the first public key to obtain a second public key, and send the second public key to an external channel through a corresponding second port.

That is to say, the second encrypted reverse firewall receives the first public key pk from the information receiving entity through the first port, and publicizes the first public key pk according to the obtained first random number r ₁ through the internal session unit. The key is re-randomized to obtain the second public key pk', and the second public key pk' is sent to the external channel through the corresponding second port.

S102, the second port of the first password reverse firewall receives the second public key from the external channel, uses the internal session unit to transparently transmit the second public key to the message sending entity through the corresponding first port, and transmits the second public key Make a note.

That is to say, the first password reverse firewall receives the second public key pk' from the external channel through the second port, and records the second public key pk' through the internal session unit, and passes the second public key pk' through the corresponding The first port transparently transmits to the message sending entity.

S103. The first port of the first password reverse firewall receives the first ciphertext sent by the message sending entity, uses the internal session unit to extract the random number from the first ciphertext to obtain the second random number, and based on the second random number Perform ciphertext re-randomization on the first ciphertext to obtain the second ciphertext, and send the second ciphertext to the external channel through the corresponding second port.

That is to say, the first password reverse firewall receives the first ciphertext c sent from the message sending entity through the first port, and encrypts the first ciphertext c according to the obtained second random number _r2 through the internal session unit Randomize again to obtain the second ciphertext c', and send the second ciphertext c' to the external channel through the corresponding second port.

S104, the second port of the second password reverse firewall receives the second ciphertext from the external channel, uses the internal session unit to process the second ciphertext according to the first random number to obtain the third ciphertext, and sends the third ciphertext The text is transparently transmitted to the message receiving entity through the corresponding first port.

That is to say, the second password reverse firewall receives the second ciphertext c' from the external channel through the second port, and processes the second ciphertext c' according to the first random number _r1 through the internal session unit to obtain The third ciphertext c", and transparently transmit the third ciphertext c" to the message receiving entity through the corresponding first port.

Thus, the security defense method of the cryptographic reverse firewall of the present application extracts a random number from the first public key to obtain the first random number, and performs public key re-randomization processing on the first public key according to the first random number to obtain Obtaining the second public key, performing random number extraction on the first ciphertext to obtain a second random number, and re-randomizing the ciphertext on the first ciphertext according to the second random number to obtain a second ciphertext, and then, Process the second ciphertext according to the first random number to obtain the third ciphertext, thereby effectively reducing the number of random numbers generated by the password reverse firewall during operation, reducing the dependence on trusted random sources, and improving the realizable sex.

Specifically, as shown in Figure 5, the random number extraction is performed on the first public key to obtain the first random number, including:

S201. Encode the first public key by using a first preset injective function to map the first public key to an input space of a first preset pseudo-random permutation function and obtain first encoding information.

That is to say, the first public key pk can be encoded by the first preset injective function Map1, so as to map the first public key pk to the input space of the first preset pseudo-random permutation function Per1 and obtain the first encoding information r _pk ←Map1(pk).

其中，

为密文空间。Optionally, the first preset injective function Map1 can be preset as

in,

is the ciphertext space.

S202. If the first coded information already exists, perform an alarm and block all message transmissions.

It can be understood that if the internal session unit of the second password reverse firewall detects that the first encoded information r _pk already exists, the internal session unit will give an alarm reminder and block all message transmissions in the second password reverse firewall .

S203. If the first encoding information does not exist, record the first encoding information, and use the first preset pseudo-random permutation function and the key of the first preset pseudo-random permutation function to permute the first encoding information to obtain the first The random number, wherein the key of the first preset pseudo-random permutation function is externally injected or automatically generated when the second password reverse firewall is started.

It can be understood that if the first encoded information r _pk does not exist, record the first encoded information r _pk in the list, and use the first preset pseudo-random permutation function Per1 and the key of the first preset pseudo-random permutation function s ₁ permutes the first encoded information r _pk to obtain the first random number r ₁ ←Per1(s ₁ , r _pk ), where the key s ₁ of the first preset pseudo-random permutation function is reversed in the second password Injected externally or generated automatically when the firewall starts.

其中，

为密钥空间。Optionally, the first preset pseudo-random permutation function Per1 can be preset as

in,

is the key space.

Further, performing public key re-randomization processing on the first public key according to the first random number to obtain a second public key includes:

Using a preset public key rerandomization function to perform public key rerandomization processing on the first public key according to the first random number to obtain a second public key.

That is to say, the public key re-randomization pk′←Keymaul(pk, r ₁ ) can be performed on the first public key pk according to the first random number r ₁ through the preset public key re-randomization function Keymaul to obtain the second public key Key pk'.

Further, as shown in Figure 6, random number extraction is performed on the first ciphertext to obtain a second random number, including:

S301. Encode the first ciphertext by using a second preset injective function to map the first ciphertext to an input space of a second preset pseudo-random permutation function and obtain second encoding information.

That is to say, the first ciphertext c can be encoded by the second preset injective function Map2 to map the first ciphertext c to the input space of the second preset pseudo-random permutation function Per2 and obtain the second encoding information r _c ← Map2(c).

其中，

为公钥空间。Optionally, the second preset injective function Map2 can be preset as

in,

is the public key space.

S302. If the second coded information already exists, perform an alarm and block all message transmissions.

It can be understood that if the internal session unit of the first password reverse firewall detects that the second coded information _rc already exists, the internal session unit will give an alarm reminder and block all message transmissions in the first password reverse firewall .

S303. If the second encoding information does not exist, record the second encoding information, and use the second preset pseudo-random permutation function and the key of the second preset pseudo-random permutation function to replace the second encoding information to obtain the second The random number, wherein the key of the second preset pseudo-random permutation function is externally injected or automatically generated when the first password reverse firewall is started.

It can be understood that if the second coded information _rc does not exist, record the second coded information _rc in the list, and use the second preset pseudo-random permutation function Per2 and the key of the second preset pseudo-random permutation function s ₂ permutes the second coded information r _c to obtain the first random number r ₂ ←Per2(s ₂ , r _c ), where the key s ₂ of the second preset pseudo-random permutation function is reversed in the first password Injected externally or generated automatically when the firewall starts.

其中，

为密钥空间。Optionally, the first preset pseudo-random permutation function Per2 can be preset as

in,

is the key space.

Therefore, the password reverse firewall in the embodiment of the present invention adopts a pseudo-random permutation strategy, by embedding two pseudo-random permutation functions Per1 and Per2 in the password reverse firewall, and during the startup phase of the password reverse firewall, through external injection or The key s ₁ and s ₂ of the pseudo-random permutation function are generated in a self-generated way, and when the transmitted public key or ciphertext needs to be pseudo-randomized during the operation of the protocol, the public key to be processed is firstly used by the injective function or ciphertext, and then map it to the input space of the pseudo-random permutation function, and then use the pseudo-random permutation function to permute it, and finally, use the random number obtained from the permutation to process the public key or ciphertext to be processed Then randomize to obtain the correspondingly processed public key or ciphertext.

And, adopting the online watchdog strategy, by setting up an online watchdog module with alarm function, real-time monitoring of the data passing through the password reverse firewall, and alarming when the risk of subversion attack is detected, for example, for each pseudo-random The permutation creates a list to record all the data entered into the permutation under the current permutation key, and checks the input before each call of the pseudo-random permutation. Once the input is found to be consistent with a record in the list Repeat (collision), then the password reverse firewall externally reports to the police, simultaneously, cuts off all communication between the computer and the outside world, and the network protocol operation suspends.

It should be noted that when generating the first public key pk, the following conditions are met: the probability that the two randomly generated public keys are equal is less than or equal to the first preset value, and the two randomly generated public keys are used to pair the randomly generated two The probability that two ciphertexts generated by encrypting a legitimate plaintext are equal is less than or equal to the first preset value.

且(a，b)≠(c，d)。It can be understood that when the first public key pk is generated, the probability that the two randomly generated public keys (pk ₀ , sk ₀ ) are equal is less than or equal to the first preset value Pr[pk ₀ =pk ₁ ]≤negl( λ), and using two randomly generated public keys to encrypt two randomly generated legal plaintexts m ₀ and m ₁ , the probability that the generated two ciphertexts are equal is less than or equal to the first preset value Pr[Enc(pk _a , m _b )=Enc(pk _c ,m _d )]≤negl(λ), where,

And (a, b)≠(c, d).

Further, performing ciphertext re-randomization processing on the first ciphertext according to the second random number to obtain the second ciphertext, including:

Using a preset ciphertext rerandomization function to perform ciphertext rerandomization processing on the first ciphertext according to the second random number and the second public key to obtain the second ciphertext.

That is to say, the first ciphertext c can be re-randomized according to the second random number r ₂ and the second public key pk' through the preset ciphertext re-randomization function Rerand c'←Rerand(pk,c , r ₂ ), to obtain the second ciphertext c′.

Further, the second ciphertext is processed according to the first random number to obtain the third ciphertext, including:

Using a preset ciphertext recovery function to recover the second ciphertext according to the first random number to obtain the third ciphertext.

That is to say, the second ciphertext c' can be recovered c"←CKeymaul(c', r ₁ ) according to the first random number r ₁ through the preset ciphertext recovery function CKeymaul to obtain the third ciphertext c".

相应的，密文恢复函数CKeymaul可设计为：

密文再随机化函数Rerand可设计为：

Optionally, taking the El-Gamal public key encryption system as an example in the embodiments of the present invention, the public key re-randomization function Keymaul can be designed as:

Correspondingly, the ciphertext recovery function CKeymaul can be designed as:

The ciphertext re-randomization function Rerand can be designed as:

Further, the messages received and sent by the first password reverse firewall and the second password reverse firewall all meet the six-tuple format, if not, an alarm reminder is given, wherein the six-tuple format includes the protocol type identifier, the session identifier , the identifier of the message sending entity, the identifier of the message receiving entity, the content of the message, and the combined data of the message.

That is to say, if during the operation of the protocol, the messages received and sent by the first password reverse firewall and the second password reverse firewall do not meet the six-tuple format, an alarm will be issued, and at the same time, the first password reverse firewall will be prohibited. Information exchange is performed to the firewall and the second password reverse firewall.

Further, as shown in Figure 7, the security defense method of password reverse firewall also includes:

S401. After receiving the first public key, the second encrypted reverse firewall generates an internal session unit and marks the internal session unit, where the tag information includes a protocol type identifier, a session identifier, and a message receiving entity identifier.

It can be understood that the corresponding internal session unit in the second password reverse firewall can be determined through the tag information including the protocol type identifier, the session identifier and the message receiving entity identifier.

S402. After receiving the second ciphertext, the second password reverse firewall also checks whether the internal session unit exists, and if not, sends an alarm; if it exists, runs the internal session unit.

It should be understood that if the second password reverse firewall finds that the internal session unit does not exist by searching the flag information of the internal session unit, an alarm will be given, and at the same time, all communications in the second password reverse firewall will be blocked. If it is found that the internal unit exists, then run the internal session unit.

Further, as shown in Figure 8, the security defense method of password reverse firewall also includes:

S501. After receiving the second public key, the first cryptographic reverse firewall generates an internal session unit, and marks the internal session unit, where the tag information includes a protocol type identifier, a session identifier, and a message sending entity identifier.

It can be understood that the corresponding internal session unit in the first password reverse firewall can be determined through the protocol type identifier, the session identifier and the message sending entity identifier.

S502. After receiving the first ciphertext, the first password reverse firewall also checks whether the internal session unit exists, and if not, sends an alarm; if it exists, runs the internal session unit.

It should be understood that if the first password reverse firewall finds that the internal session unit does not exist by searching the tag information of the internal session unit, then an alarm will be issued, and at the same time, all communications in the first password reverse firewall will be blocked. If it is found that the internal unit exists, then run the internal session unit.

In summary, according to the security defense method of the password reverse firewall in the embodiment of the present invention, first, the first port of the second password reverse firewall receives the first public key sent from the message receiving entity, and uses the internal session unit to exchange the first public key with the first public key. Extract random numbers from the key to obtain the first random number, perform public key re-randomization on the first public key according to the first random number to obtain the second public key, and send the second public key to the The external channel sends, and then, the second port of the first password reverse firewall receives the second public key from the external channel, uses the internal session unit to transparently transmit the second public key to the message sending entity through the corresponding first port, and The second public key is recorded, and then, the first port of the reverse firewall with the first password receives the first ciphertext sent by the message sending entity, and uses the internal session unit to extract the random number from the first ciphertext to obtain the second random number , and perform ciphertext re-randomization on the first ciphertext according to the second random number to obtain the second ciphertext, and send the second ciphertext to the external channel through the corresponding second port, and finally, the second ciphertext reverses The second port of the firewall receives the second ciphertext from the external channel, uses the internal session unit to process the second ciphertext according to the first random number to obtain the third ciphertext, and passes the third ciphertext through the corresponding first port Transparently transmit to the message receiving entity. As a result, the number of random numbers generated during the operation of the password reverse firewall is effectively reduced, the degree of dependence on trusted random sources is reduced, and the realizability is improved.

Further, based on the security defense method of the password reverse firewall in the above-mentioned embodiment of the present invention, the embodiment of the present invention also proposes a password reverse firewall, which includes the security defense of the password reverse firewall described in the above-mentioned embodiment of the invention method.

It should be noted that the specific implementation manners of the encryption reverse firewall in the embodiment of the present invention correspond to the specific implementation manners of the security defense method of the encryption reverse firewall in the embodiment of the present invention, so details are not repeated here.

To sum up, according to the password reverse firewall of the embodiment of the present invention, the security defense method of the above password reverse firewall can effectively reduce the number of random numbers generated by the password reverse firewall during operation, and reduce the dependence on trusted random sources. degree, to improve realizability.

It should be noted that the logic and/or steps shown in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, apparatus, or device and execute instructions), or in combination with these Instructions are used to execute systems, devices, or equipment. For the purposes of this specification, a "computer-readable medium" may be any device that can contain, store, communicate, propagate or transmit a program for use in or in conjunction with an instruction execution system, device or device. More specific examples (non-exhaustive list) of computer-readable media include the following: electrical connection with one or more wires (electronic device), portable computer disk case (magnetic device), random access memory (RAM), Read Only Memory (ROM), Erasable and Editable Read Only Memory (EPROM or Flash Memory), Fiber Optic Devices, and Portable Compact Disc Read Only Memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program can be printed, since the program can be read, for example, by optically scanning the paper or other medium, followed by editing, interpretation or other suitable processing if necessary. The program is processed electronically and stored in computer memory.

It should be understood that various parts of the present invention can be realized by hardware, software, firmware or their combination. In the embodiments described above, various steps or methods may be implemented by software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented by any one or combination of the following techniques known in the art: Discrete logic circuits, ASICs with suitable combinational logic gates, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), etc.

In the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structure, material or feature is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

In describing the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inner", "Outer", "Clockwise", "Counterclockwise", "Axial", The orientation or positional relationship indicated by "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the referred device or element Must be in a particular orientation, be constructed in a particular orientation, and operate in a particular orientation, and therefore should not be construed as limiting the invention.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

In the present invention, unless otherwise clearly specified and limited, terms such as "installation", "connection", "connection" and "fixation" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection , or integrated; it may be mechanically connected or electrically connected; it may be directly connected or indirectly connected through an intermediary, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise specified limit. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

In the present invention, unless otherwise clearly specified and limited, the first feature may be in direct contact with the first feature or the first and second feature may be in direct contact with the second feature through an intermediary. touch. Moreover, "above", "above" and "above" the first feature on the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. "Below", "beneath" and "beneath" the first feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is less horizontally than the second feature.

Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention, those skilled in the art can make the above-mentioned The embodiments are subject to changes, modifications, substitutions and variations.

Claims (7)

1. A security defense method for a password reverse firewall, characterized in that, the password reverse firewall comprises a first password reverse firewall and a second password reverse firewall, and the first password reverse firewall corresponds to a message sending entity Setting, the second password reverse firewall is set corresponding to the message receiving entity, each of the password reverse firewalls includes a first port and a second port, the first port is connected to the entity, and the second port Connected to an external channel, each of the password reverse firewalls is used to process messages transmitted between the entity and the external information, and the method includes the following steps: The first port of the second cryptographic reverse firewall receives the first public key sent by the message receiving entity, uses the internal session unit to extract a random number from the first public key to obtain a first random number, and according to performing public key re-randomization processing on the first public key with the first random number to obtain a second public key, and sending the second public key to the external channel through a corresponding second port; The second port of the first password reverse firewall receives the second public key from the external channel, and uses the internal session unit to transparently transmit the second public key to the message sending entity through the corresponding first port. pass, and record the second public key; The first port of the first password reverse firewall receives the first ciphertext sent by the message sending entity, uses the internal session unit to perform random number extraction on the first ciphertext to obtain a second random number, and according to performing ciphertext re-randomization processing on the first ciphertext by the second random number to obtain a second ciphertext, and sending the second ciphertext to the external channel through a corresponding second port; The second port of the second password reverse firewall receives the second ciphertext from the external channel, and uses the internal session unit to process the second ciphertext according to the first random number to obtain the third ciphertext. ciphertext, and transparently transmit the third ciphertext to the message receiving entity through the corresponding first port; The extracting the random number from the first public key to obtain the first random number includes: Encoding the first public key by using a first preset injective function to map the first public key to an input space of a first preset pseudo-random permutation function and obtain first encoding information; If the first coded information already exists, perform an alarm reminder and block all message transmissions; If the first encoding information does not exist, record the first encoding information, and use the first preset pseudo-random permutation function and the key of the first preset pseudo-random permutation function to pair the first The coded information is permuted to obtain the first random number, wherein the key of the first preset pseudo-random permutation function is externally injected or automatically generated when the second password reverse firewall is started; The extracting the random number from the first ciphertext to obtain the second random number includes: encoding the first ciphertext by using a second preset injective function to map the first ciphertext to an input space of a second preset pseudo-random permutation function and obtain second encoding information; If the second coded information already exists, give an alarm reminder and block all message transmissions; If the second encoding information does not exist, record the second encoding information, and use the second preset pseudo-random permutation function and the key of the second preset pseudo-random permutation function to pair the second The encoded information is substituted to obtain the second random number, wherein the key of the second preset pseudo-random permutation function is externally injected or automatically generated when the first password reverse firewall is started. 2. the security defense method of password reverse firewall according to claim 1, is characterized in that, described first public key is carried out public key randomization process again to obtain second public key according to described first random number keys, including: performing public key re-randomization processing on the first public key according to the first random number by using a preset public key re-randomization function to obtain the second public key. 3. the security defense method of password reverse firewall according to claim 1, is characterized in that, described first ciphertext is carried out ciphertext randomization process again to obtain second ciphertext according to described second random number. text, including: performing ciphertext rerandomization processing on the first ciphertext according to the second random number and the second public key by using a preset ciphertext rerandomization function to obtain the second ciphertext. 4. the security defense method of password reverse firewall according to claim 1, is characterized in that, described second ciphertext is processed according to described first random number to obtain the 3rd ciphertext, comprising: Restoring the second ciphertext according to the first random number by using a preset ciphertext restoration function to obtain the third ciphertext. 5. according to the security defense method of the password reverse firewall described in any one in claim 1-4, it is characterized in that, the message that described first password reverse firewall and described second password reverse firewall receive and send All meet the six-tuple format, and if not, an alarm reminder is given, wherein the six-tuple format includes the protocol type identifier, session identifier, message sending entity identifier, message receiving entity identifier, message content and combined data of the message. 6. the security defense method of password reverse firewall according to claim 5, is characterized in that, described method also comprises: After receiving the first public key, the second password reverse firewall generates the internal session unit and marks the internal session unit, wherein the tag information includes the protocol type identifier, the session identifier and The message receiving entity identifier; After the second password reverse firewall receives the second ciphertext, it also checks whether the internal conversational unit exists, and if it does not exist, it will give an alarm; if it exists, it will run the internal conversational unit. 7. the security defense method of password reverse firewall according to claim 5, is characterized in that, described method also comprises: After receiving the second public key, the first password reverse firewall generates the internal session unit and marks the internal session unit, wherein the tag information includes the protocol type identifier, the session identifier and The message sending entity identifier; After the first password reverse firewall receives the first ciphertext, it also checks whether the internal conversational unit exists, and if it does not exist, it will give an alarm; if it exists, it will run the internal conversational unit.

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