JP5408372B2 - Encryption implementation control system - Google Patents

Description

The present invention provides a wireless private branch exchange network (wireless LAN: IEEE 802.11) or a cellular network (for example, 3
The present invention relates to an encryption method implemented at an end-to-end of a wireless network (mobile communication network) such as GPP.

Typical wireless network systems include a network system (wireless LAN system) using a wireless LAN (IEEE 802.11) and a cellular network system (3GPP).

For example, as shown in FIG. 1, a wireless LAN system includes a media server, a wireless network gateway (GW) connected to the media server via a link (network), and an IP network (for example, the Internet) connected to the wireless network gateway. And a terminal (PC (Personal Computer), PDA (Personal Digital Assistant), etc.) is connected to the AP via a wireless link (wireless transmission path). A wireless section of the data transmission path is configured between the AP and the terminal.

  Normally, communication data is encrypted in a wireless network in consideration of communication security. In the wireless LAN system as shown in FIG. 1, as shown in FIG. 2, encryption processing based on IEEE802.11 is performed in the wireless section between the terminal and the AP. In the wireless LAN (IEEE802.11), for example, encryption by WPA2 (Wi-Fi Protected Access 2) is performed as an encryption method (the encryption algorithm is TKIP (Temporal Key Integrity Protocol) or AES (Advanced Encryption). Standard)).

Further, for example, encryption processing by IPsec is performed between the terminal and the GW. Further, application level encryption (for example, SRTP (Secure Real-time Transport Protocol: RFC3771)) is performed between the media server (server) and the terminal.

For example, as shown in FIG. 3, a cellular network system (mobile phone network system) includes a server, a gateway (GW: router) connected to the server via a link, and a GW via an IP network such as the Internet. A switch (xGSN) to be connected, a base station controller (Radio Network Controller: RNC) connected to the switch via a link, and a base station (Node B or Node B) connected to the base station controller via a link BTS (Base Transceiver System)). A mobile terminal (User Equipment or Mobile Node) is a wireless link (wireless transmission path) to the base station device.
Connected through. A radio section of the data transmission path is configured between the mobile terminal and the base station apparatus.

  In the case of a cellular network (3GPP) as shown in FIG. 3, as shown in FIG. 4, for example, encryption by KASUMI algorithm F8 mode is performed between the RNC and the mobile terminal (UE). The encryption similar to the scheme shown in FIG. 2 can be performed between the UE and the GW and between the UE and the server.

  Currently, the encryption method applied in the wireless network is uniquely determined when the wireless section is constructed, and is not changed for each communication.

When performing streaming delivery with immediacy (real-time) using a wireless network, RTP (Real-Time Transfer Protocol) is generally used as a communication protocol. When using RTP, RTSP (Real-Time Transfer Streaming Protocol)
ol) is initially negotiated. In addition, RTCP (RTP control protocol) is used to feed back information on the receiving side during communication. Furthermore, for streaming data (multimedia data: RTP packets), SRT
Encryption processing such as P / SRTCP (Secure RTP / Secure Real-time Transport Protocol) is performed.

  Further, when streaming data is distributed to a terminal device in a private branch exchange network such as a corporate LAN via a wireless network, a VPN (Virtual Private Network) is provided to provide a secure connection between the terminal device and the GW. ) Setting is performed to conceal communication by IPsec (Security Architecture for Internet Protocol).

JP 2005-347789 A

  As shown in FIGS. 2 and 4, in the wireless section in the wireless network, in addition to encryption based on IEEE802.11, encryption by SRTP and / or encryption by IPsec is performed. In this way, encryption is performed in duplicate. For this reason, the encryption processing is duplicated. Such overlapping encryption processing imposes a useless load on the device that performs the encryption processing and wastes resources for the encryption processing.

  An object of an aspect of the present invention is to provide a technique for preventing unnecessary encryption processing from being performed when encryption processing becomes redundant.

The aspect of the present invention employs the following means in order to achieve the object described above.
The first aspect is the first encryption means for performing encryption for communication in the first section between the terminal device and the first relay device;
Second encryption means for performing encryption for communication in the second section including the first section from the terminal device to the second relay apparatus via the first relay apparatus;
Control means for controlling the first encryption means so that the encryption of the first section is not performed when the encryption of the second section is performed,
The control means includes
In accordance with the second section encryption performed by the second encryption means, control the encryption performed by the first encryption means for the channel used for transmission of user data,
Controls the execution of encryption by the first encryption means regardless of whether or not the second encryption means is encrypted for the channel used for transmission of the control signal. It is an encryption implementation control system.

  According to a first aspect, when the control unit monitors traffic in the second section and detects traffic for performing encryption in the second section, encryption in the second section is performed. It can be configured to determine.

  In the first mode, the first encryption unit waits for the start of encryption in the first section in accordance with an instruction notified from the control unit when encryption of the second section is performed. It can be constituted so that.

  In the first aspect, when the control unit detects the stop of encryption performed in the second interval, the control unit notifies the first encryption unit of an instruction to start encryption in the first interval. It can be constituted as follows.

  A 1st aspect can be comprised so that the said control means may be provided in a said 1st relay apparatus.

  A 1st aspect can be comprised so that the said control means may be provided in the said terminal device.

  In the first aspect, for example, KASUMI encryption can be applied as the encryption method for the first section. IPsec or SRTP can be applied as the encryption method for the second interval.

In the first aspect, the first encryption means performs encryption for the user data communication path and the control data communication path in the first section,
The second encryption means encrypts user data transferred in the second section,
The first encryption unit waits for the start of encryption for the user data communication path according to an instruction from the control unit when the second section encryption is performed, while the control data The communication channel can be configured to perform encryption.

A second aspect is a relay device that relays data,
An encryption processing unit for encrypting communication in the first section between the own device and the terminal device;
It is determined whether or not encryption of communication in the second interval including the first interval from the terminal device to another relay device via its own device is performed, and encryption in the second interval is performed. When implemented, the relay device includes a control unit that puts the encryption unit into a state in which the encryption of the first section is not performed.

A third aspect is a terminal device that communicates with another device via two or more relay devices,
A first encryption processing unit that encrypts communication with the first relay device for a first section between the own device and the first relay device;
A second encryption processing unit for performing encryption with the second relay device for a second section including the first section from the own device via the first relay device to the second relay device;
And a control unit that puts the first encryption processing unit into a state in which the encryption of the first interval is not performed when the encryption of the second interval is performed.

  The configuration that can be adopted in the first aspect can also be applied to the second and third aspects. Further, the present invention can be realized as a method invention having the same features as the first to third aspects.

  According to the aspect of the present invention, it is possible to prevent unnecessary encryption processing from being performed when encryption processing becomes redundant.

The structural example of a wireless LAN (IEEE802.11) system is shown. An example of encryption processing in a wireless LAN system is shown. The structural example of a cellular network (3GPP) system is shown. An example of encryption processing in a cellular network system is shown. The wireless LAN system shows a state where encryption processing in a wireless section is avoided. In the cellular network system, a state where encryption processing in a wireless section is avoided is shown. 2 shows a configuration example of a network system (encryption processing control system) in the present embodiment. An outline of IPsec is shown. The data structure of an ESP block is shown. A network system configuration according to a specific example is shown, and an explanation of encryption processing control of the first encryption section based on a determination on the network side is shown. It is a flowchart which shows the process example by the encryption process part of RNC. It is a flowchart which shows the process example by the judgment part of RNC. An explanation will be given of encryption processing control in the first encryption section when the terminal device determines whether or not the encryption processing is performed in the second encryption section. An outline of the encryption process in the case where DTCH as a user channel and DCCH as a control channel are provided between the RNC and the UE that are the first encryption sections will be shown.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The configuration of the embodiment is an exemplification, and the present invention is not limited to the configuration of the embodiment.

〔Overview〕
As described above, in the current wireless network system, duplicate encryption is performed. In view of such a situation, as an embodiment of the present invention, for example, an access point (AP) or a wireless network gateway (G in the wireless LAN system as shown in FIG.
W) includes an apparatus capable of observing SRTP negotiation at an end-to-end (for example, a media server and a mobile terminal) in accordance with RTSP (Real Time Streaming Protocol). At this time, when the encryption process by SRTP is performed for a certain RTP session, the encryption process in the wireless LAN (wireless section) is not performed for the RTP session.

  However, this processing is performed independently from communication related to other sessions and other media occurring simultaneously with the above RTP session. For example, a mobile terminal (terminal device) may perform Web access in parallel with streaming delivery. At this time, when encryption processing in the wireless section is requested for the session related to the Web access, encryption processing in the wireless section is performed.

Further, in the embodiment, it is monitored whether IPsec is performed for communication related to a certain RTP session, and when it is performed, encryption processing in a wireless section is avoided.
FIG. 5 shows a state in which wireless section encryption processing is avoided in the wireless LAN system as shown in FIG. 1, and FIG. 6 shows wireless section encryption in the cellular network system as shown in FIG. It shows the state where the conversion process is avoided.

  FIG. 7 is a diagram illustrating a configuration example of a network system (encryption processing control system) in the present embodiment. The network system shown in FIG. 7 includes a transmission / reception device 10, a communication device 20 as a second relay device, a communication device 30 as a first relay device, and a terminal device 40.

  The terminal device 40 has a data transmission / reception function, and data transmitted / received between the terminal device 40 and the transmission / reception device 10 passes through a predetermined communication path. One end point of this communication path is the terminal device 40, and the other is the transmission / reception device 10. The communication device 20 and the communication device 30 are arranged on a communication path and function as a relay device for data transmitted / received between the transmission / reception device 10 and the terminal device 40.

  Regarding such a communication path, a section between the terminal device 40 and the communication apparatus 30 is defined as a first encryption section (corresponding to the first section) in which data transmitted and received in this section is encrypted. Yes. On the other hand, a section between the terminal device 40 and the communication device 20 is defined as a second encryption section (corresponding to the second section) in which data is encrypted in this section.

  Thus, the first encryption interval is included (overlapped) in the second encryption interval. Therefore, when encrypted communication is performed in parallel in both the first encryption section and the second encryption section, the data flowing through the first encryption section is the second encryption section. The encrypted data encrypted by the applied encryption method is further encrypted by the encryption method applied for the first encryption section. That is, redundant encryption processing is performed in the first encryption section.

  Usually, different types of encryption schemes are applied to each of the first encryption section and the second encryption section. However, the same type of encryption scheme is not prevented from being applied to the first and second encryption sections.

  The terminal device 40 includes a first encryption processing unit 41 for performing encrypted communication in the first encryption section and a second encryption processing unit for performing encrypted communication in the second encryption section. 42.

  The communication device 30 includes an encryption processing unit 31 for performing encrypted communication in the first encryption section. The encryption processing unit 31 negotiates and initializes the encryption method (first encryption method) applied to the first encryption section with the first encryption processing unit 41 of the terminal device 40. Then, the communication device 30 is brought into a state where encrypted communication based on the first encryption method can be performed between the terminal device 40 and the terminal device 40 (first encryption section).

  When encrypted communication in the first encryption section is performed, encrypted data encrypted by the first encryption method is transmitted from one of the communication device 30 and the terminal device 40, On the other hand, the encrypted data is decrypted.

  Thus, the encryption processing unit 31 and the first encryption processing unit 41 function as a first encryption unit that encrypts data flowing in the first encryption section.

  The communication device 20 includes an encryption processing unit 21 for performing encrypted communication in the second encryption section. The encryption processing unit 21 negotiates and initializes the second encryption method with the second encryption processing unit 42 of the terminal device 40, and is applied in the second encryption section. Encrypted communication based on (second encryption method) is put into a state where it can be implemented.

  When encrypted communication in the second encryption section is performed, encrypted data encrypted by the second encryption method is transmitted from one of the communication device 20 and the terminal device 40, On the other hand, the encrypted data is decrypted.

The encryption processing unit 21 and the second encryption processing unit 42 function as a second encryption / decryption unit that performs encryption and decryption processing for the second encryption section.

  The communication device 30 further includes a determination unit 32 for determining whether or not to perform encryption in the second encryption section. The determination unit 32 functions as a control unit that controls the execution of encryption in the first encryption section according to whether or not encryption is performed in the second encryption section.

The determination unit 32 monitors communication (traffic) between the communication device 20 and the terminal device 40 (second encryption section) and determines whether encryption is performed in the second encryption section. Determine (judgment).

  When encryption is not performed in the second encryption section, nothing is done to the encryption processing unit 31. In this case, the encryption processing unit 31 performs negotiation and initial setting related to encryption in the first encryption section, and performs encryption / decryption processing of data transmitted / received in the first encryption section. .

  On the other hand, when encryption by the second encryption method is performed, the determination unit 32 stops (stops) the encryption processing (data encryption / decryption) by the encryption processing unit 31. be able to.

In addition, when the determination unit 32 detects that the encryption of the second encryption interval is stopped in the monitoring of the second encryption interval, the determination unit 32 determines the first encryption interval of the first encryption interval. If the encryption is stopped, the encryption processing unit 31 can start the encryption process.
As described above, the encryption for the first encryption section is performed based on the determination result of whether or not the encryption of the second encryption section is performed. For this reason, the determination unit 32 of the communication device 30 checks whether or not encryption for the second encryption section is performed.

  When encryption for the second encryption interval is performed, encryption for the first encryption interval is not performed, and when encryption for the second encryption interval is not performed, the first encryption is performed. Encrypted sections are encrypted. Further, when it is detected (detected) that the encryption of the second encryption section is not performed after the encryption for the first encryption section is stopped, the encryption for the first encryption section is performed. Encryption starts (resumes).

  Here, regarding the encryption for the first encryption interval, all necessary settings for the encryption of the first encryption interval are performed regardless of whether the encryption for the second encryption interval is performed or not. Thus, the start of encryption for the first encryption interval is suspended.

  Further, when the first encryption section has a communication path independent from the second encryption section, for example, in the 3GPP system, the DCCH (Control Channel independent of DTCH (Dedicated Traffic CHannel) that handles user data is used. When there is a Dedicated Control CHannel), only the DTCH is subject to control whether or not encryption is performed, and the DCCH is not included in the control subject (encrypted regardless of the second encryption interval). Can be made).

7 shows an example in which the communication device 30 includes the encryption processing unit 31 and the determination unit 32. However, the determination unit 32 may be located at a position physically separated from the encryption processing unit 31 (for example, a device different from the communication device 30). That is, an encryption processing start / stop instruction based on the determination result in the determination unit 32 is transmitted to the encryption processing unit 31, and the encryption processing unit 31 responds to the data related to communication to be controlled according to the start / stop instruction. What is necessary is just to be comprised so that an encryption process may be implemented.

〔Concrete example〕
<Overview of IPsec>
FIG. 8 shows an outline of IPsec. In IPsec, negotiation regarding an encryption method is performed by the procedure of IKE (Internet Key Exchange: RFC2409) before the start of communication.
In phase 1, the encryption method used in phase 2 is determined between hosts (devices) that perform communication, and an encryption key for encryption is generated. The encryption key generated in phase 1 is shared between devices.

In Phase 2, the encryption method and encryption key used in IPsec using the shared key (
SA: security association) is determined. This procedure is performed using a specific packet. For example, a packet of ISAKMP (Internet Security Association and Key Management Protocol: RFC2408) is used in this phase 2.

  Therefore, in the network system shown in FIG. 7, for example, the confirmation of the IKE sequence using the ISAKMP packet performed between the communication device 20 and the terminal device 40 means that the communication device 30 located in the middle of them. (Determining part 32) is possible.

  In ISAKMP, a port number “500” of TCP / UDP (Transfer Control Protocol / User Datagram Protocol) is assigned by IANA (Internet Assigned Number Authority).

  FIG. 9 shows the data structure of the ESP block. When the negotiation by IKE is completed, in IPsec, a data block to be transferred (TCP / UDP packet in the example of FIG. 9) is encapsulated in a block called ESP (Encapsulating Security Payload). That is, the encapsulated data block is mapped to the payload data storage area in the ESP.

The ESP block is transferred with the IP header added (the ESP with the IP header added).
The block is referred to as an “ESP packet”). ESP packet payload, ie ES
The P block is encrypted based on IPsec. For this reason, the ESP packet is transferred in a secure environment. Note that the number “50” assigned for ESP is stored in the “Next Header field” of the IP header assigned to the ESP block.

  IPsec has a transport mode and a tunnel mode. In the transport mode, the transmission host encrypts the original data to be transmitted with the encryption key, adds the IP header, and transmits. This IP packet is received by the receiving host. The receiving host removes the header from the IP packet and performs the decoding process on the remaining data portion to obtain the original data.

  Thus, in the transport mode, an IP packet having encrypted data (ESP block) is transmitted and received between the transmission host and the reception host.

In tunnel mode, IP packets are transferred from the sending host to the sending gateway. The transmission side gateway (IPsec processing gateway) encrypts the IP packet from the transmission host, encapsulates it in the IP packet, and transfers it to the reception side gateway (IPsec processing gateway). At the receiving gateway, the IP header is removed from the IP packet, and the remaining data portion is decoded to obtain the original IP packet. The receiving gateway transfers this IP packet to the receiving host without encryption. Thus, in the tunnel mode, only communication between gateways is encrypted.

In the present embodiment, it is assumed that an IPsec transport mode is used.
FIG. 10 shows the configuration of a network system according to a specific example and the explanation of the encryption processing control of the first encryption section based on the determination on the network side.

  As shown in FIG. 10, a cellular network system (3GPP) is shown as a system according to a specific example. The cellular network system includes a server 50 that distributes data such as streaming data in response to a data request, a gateway (GW) 60 connected to the server via a link, and an IP network (eg, the Internet) connected to the GW 60. Exchange (xGSN) 70, a base station controller (RNC) 80 connected to xGSN 70 via a link, and a base station device (Node B) 90 connected to RNC 80 via a link. The terminal apparatus (UE) 100 is connected to the base station apparatus 90 via a radio link (radio transmission path).

  In FIG. 10, the server 50 and the UE 100 serve as two end points of the communication path. On this communication path, the section between the UE 100 and the RNC 80 corresponds to the first encryption section described with reference to FIG. 7, and the section between the UE 100 and the GW 80 is the first encryption section. This corresponds to the second encryption section including

  UE100 is corresponded to the terminal device 40 provided with the 1st encryption process part 41 and the 2nd encryption process part 42 as shown in FIG. The RNC 80 corresponds to the communication device 30 including the encryption processing unit 31 and the determination unit 32. The GW 60 corresponds to the communication device 20 including the encryption processing unit 21. The server 50 corresponds to the transmission device 10 in FIG.

  In the first encryption section, encrypted communication can be performed between the RNC 80 and the UE 100 using, for example, the KASUMI algorithm F8 mode (KASUMI encryption: first encryption method). For this reason, in the first encryption section, a communication connection (including a radio link) establishment process is performed between the RNC 80 and the UE 100. Furthermore, in order to perform encryption in the first encryption section, negotiation (message exchange) performed between the encryption processing unit 31 of the RNC 80 and the first encryption processing unit 41 of the UE 100 is performed. Initial setting of encryption according to the result of the negotiation is performed in each of the encryption processing unit 31 of the RNC 80 and the first encryption processing unit 41 of the UE 100. As a result, encrypted communication is possible in the first encryption section (FIG. 10 (1)).

In the second encryption section, encrypted communication using IPsec (transport mode: second encryption method) can be performed between the GW 60 and the UE 100. The initial setting executed in advance to start the encrypted communication by the second encryption method is a negotiation performed between the encryption processing unit 21 of the GW 60 and the second encryption processing unit 42 of the UE 100 ( Message exchange: IKE).

  The determination unit 32 in the RNC 80 can observe the traffic for which the negotiation related to the encryption in the second encryption section is being performed. Based on this observation result, it can be determined whether or not encryption is performed for the second encryption interval.

  For example, the determination unit 32 can detect traffic related to the encryption negotiation between the GW 60 and the UE 100 from the IP address and port number of the IP packet passing through the RNC 80. Regarding information for identifying traffic (IP address or the like), the IP address of the GW 80 is set in the determination unit 32 of the RNC 80 in advance. Further, the RNC 80 can acquire the IP address from the UE 100, for example, in the connection establishment procedure with the UE 100.

As described above, the TCP / UDP port number “500” is assigned to ISAKMP by IANA. Therefore, the determination unit 32 can determine whether or not IPsec negotiation is performed by checking whether or not there is traffic (packet) between the GW 60 having the port number “500” and the UE 100. .

Also, “50” is assigned to the “Next Header Field” of the IP header for a packet encrypted by IPsec. For this reason, the determination unit 32 includes the GW 60 and the UE 100.
It is possible to confirm whether or not the packet being communicated between the two is encrypted by determining whether or not the IP packet transferred between the two has “No. 50”.

  When the determination unit 32 confirms the IPsec negotiation (FIG. 10 (2)) performed between the encryption processing unit 21 of the GW 60 and the second encryption processing unit 42 of the UE 100 through the traffic observation, It is determined that encryption in the first encryption section is unnecessary (FIG. 10 (3)). The determination unit 32 performs the following process according to the state of the first encryption interval at the time of such determination.

That is, when it is determined that encryption for the first encryption section is unnecessary, the initial setting of the encryption process has been completed, but the encryption process has not started (under the encryption start standby state). Then, the determination unit 32 gives an instruction for maintaining the standby state to the encryption processing unit 31. The encryption processing unit 31 maintains the standby state according to the instruction.

  On the other hand, when the encryption processing unit 31 has already started encryption, the determination unit 32 gives an instruction to stop encryption to the encryption processing unit 31. The encryption processing unit 31 stops (stops) the encryption / decryption processing according to the stop instruction.

When the initial setting of encryption in the encryption processing unit 31 is not completed, the determination unit 32 instructs the encryption processing unit 31 to stop the start of encryption after the initial setting is completed. give. In this case, the encryption processing unit 31 follows the instruction to stop the encryption start (
(Waiting for start instruction).

  In any case described above, the determination unit 32 gives an instruction (referred to as a standby instruction) for the encryption processing unit 31 to enter the encryption start standby state. As a result, the encryption related to the first encryption section is stopped (FIG. 10 (4)). When the encryption processing unit 31 cancels the encryption, the UE 100 is notified of the cancellation, and the first encryption processing unit 41 of the UE 100 also stops the encryption / decryption processing.

  On the other hand, in the second encryption section, after the initial setting regarding this section is completed, encrypted communication by IPsec is performed between the encryption processing unit 21 of the GW 60 and the second encryption processing unit 42 of the UE 100. The For example, the encryption processing by IPsec is performed on the streaming data (FIG. 10 (5)) downloaded from the server 50 by the UE 100 (FIG. 10 (6)). The encryption performed by the encryption processing unit 21 is decrypted by the second encryption processing unit 42 of the UE 100. For this reason, security by IPsec is ensured even in the first encryption section including the wireless link. In this way, redundant encryption can be prevented from being performed in the first encryption interval.

  Thereafter, the determination unit 32 monitors the encryption in the second encryption interval, and when determining that the encryption is stopped (FIG. 10 (7)), gives an instruction to start encryption to the encryption processing unit 31, It is possible to start encryption (including resumption) in the first encryption section. At this time, the start of encryption is notified to the first encryption processing unit 41 of the UE 100. Thereby, security in the first encryption section including the wireless link is ensured.

The encryption stop in the second encryption interval is performed, for example, with the termination of the virtual closed network (VPN) connection between the UE 100 and the network (GW 60). The determination unit 32 can monitor the negotiation between the GW 60 and the UE 100 based on the traffic between the GW 60 and the UE 100 and can recognize the cancellation of the virtual private network (VPN). Alternatively, even when the destination is changed with respect to the fixed VPN connection, the recognition can be performed.

  FIG. 11 is a flowchart illustrating an example of processing performed by the encryption processing unit 31 of the RNC 80, and FIG. 12 is a flowchart illustrating an example of processing performed by the determination unit 32 of the RNC 80.

  The process illustrated in FIG. 11 is started when a connection is established via the base station 90 between the RNC 80 and the UE 100. The encryption processing unit 31 performs negotiation and initial setting regarding encryption for the first encryption interval with the first encryption processing unit 41 of the UE 100 (OP01).

  During this negotiation and initial setting, the encryption processing unit 31 determines whether or not a standby instruction has been received from the determination unit 32 (OP02). When the standby instruction is received, the encryption processing unit 31 enters a state of waiting for the start of encryption after the completion of the initial setting based on the negotiation and the negotiation result (OP03).

  On the other hand, when there is no standby instruction, the encryption processing unit 31 determines whether the negotiation and the initial setting are completed (OP04), and when the negotiation and the initial setting are not completed, Is returned to OP01. If the negotiation and the initial setting have been completed, the encryption processing unit 31 determines whether or not a standby instruction has been received from the determination unit 32 before starting encryption (OP05).

  At this time, if a standby instruction is received from the determination unit 32, the encryption processing unit 31 enters a standby state for starting encryption (OP06). If there is no standby instruction until the start of encryption, the encryption processing unit 31 starts encryption (OP07).

  If encryption processing (encryption / decryption) is performed after the start of encryption and a standby instruction is given from the determination unit 32 (OP08; YES), the encryption processing unit 31 The encryption process is stopped and the start of encryption is waited (OP09).

  If there is no standby instruction (OP08; NO), the encryption processing unit 31 determines whether or not the communication is terminated (OP10). If the communication is terminated, a predetermined termination process is performed, and the process of FIG. finish. On the other hand, if the communication is not terminated, the process returns to OP08.

  Through the processes of OP03, OP06, and OP09 described above, the encryption processing unit 31 enters a state of waiting for the start of encryption (suspended state of encryption execution) according to the standby instruction. In this case, the encryption processing unit 31 waits for an instruction to start (including restart) encryption from the determination unit 32 (OP12).

  When a start instruction is given from the determination unit 32, the process proceeds to OP07, the suspended state is released, and the encryption process is started. If there is no start instruction, it is determined whether or not the communication is terminated (OP12). At this time, if the communication is not terminated, the process returns to OP11. If the communication is terminated, a predetermined termination process is performed, and the process of FIG. 11 is terminated.

  The process illustrated in FIG. 12 is started when a connection is established between the RNC 80 and the UE 100 via the base station 90, for example. The determination unit 32 monitors traffic between the GW 60 and the UE 100 (OP21), and determines whether or not the encryption process related to the second encryption interval is performed (OP22).

  When the encryption process related to the second encryption section is performed, the determination unit 32 transmits a standby instruction to the encryption processing unit 31 (OP23). Accordingly, the encryption processing unit 31 enters a standby state for starting encryption in the first encryption section.

  Thereafter, the determination unit 32 continues to monitor traffic (OP24), and determines whether or not the encryption in the second encryption section is stopped (OP25). When the encryption is stopped, the determination unit 32 transmits an encryption start (including resumption) instruction for the first encryption interval to the encryption processing unit 31 (OP26). Thereby, the encryption process in the first encryption section is started. Such cancellation of encryption is also notified to the first encryption processing unit 41 of the UE 100.

  Thereafter, it is determined whether or not the communication is finished (OP27). If the communication is not finished, the process returns to OP21. If the communication is terminated, the determination unit 32 performs a termination process as necessary, and terminates the process of FIG.

  In the example illustrated in FIGS. 10 to 12, the RCE 80 includes the determination unit 32. On the other hand, the determination part 32 can also be comprised so that a terminal device (UE) may be equipped. That is, when communication with the network by IPsec is performed on the terminal device side, encryption in the second encryption section is performed on the network side, so encryption in the first encryption section is unnecessary. It can also be realized by notifying that it is. For example, in the case of a cellular network system (3GPP), the terminal device has a control link (control channel: DCCH) with the network side. Using this control channel, it is possible to notify that the encryption (for example, KASUMI encryption) in the first encryption section is to be stopped. Separate means (mechanism) for notifying the network side device (communication device 30 in FIG. 7) that controls the first encryption processing that the encryption processing in the first encryption section is to be stopped (stopped) It may be provided.

  FIG. 13 illustrates the encryption process control in the first encryption section when the UE 100 as the terminal device determines whether or not the encryption process is performed in the second encryption section.

  The cellular network system in FIG. 13 has substantially the same configuration as the system shown in FIG. However, in this example, the UE 100 includes a determination unit 32 that determines whether or not the encryption related to the second encryption interval is performed.

  In FIG. 13, the UE 100 establishes a connection including a radio link with the RNC 80, which is a network side device that performs encryption processing related to the first encryption interval, and encryption processing for the first encryption interval. Is initialized (FIG. 13 (1)).

After that, the encryption process for the second encryption interval (IP
(sec) negotiation and initialization are performed (FIG. 13 (2)).

  Such initial setting is performed between the encryption processing unit 21 of the GW 60 and the second encryption processing unit 42 of the UE 100. For this reason, for example, the determination unit 32 receives the notification of the implementation of the encryption initial setting for the second encryption interval from the second encryption processing unit 42, and thus the encryption of the second encryption interval is performed. Can be recognized (determined) (FIG. 13 (3)).

  Then, the UE 100 notifies the RNC 80 of an instruction to start encryption for the first encryption interval (that encryption processing is unnecessary). At this time, for example, a control channel (DCCH) for connecting the two can be used. As a result, the start of encryption in the first encryption section is stopped (FIG. 13 (4)).

Thereafter, for example, when the UE 100 downloads data such as streaming data from the server 50, the encryption processing unit 21 of the GW 60 performs IPsec on the data transferred from the server 50 to the UE 100 (FIG. 13 (5)). Encryption processing based on the above is performed and transferred to the UE 100. In the UE 100, the second encryption processing unit 42 decrypts the data. Such processing is the same as the example of FIG.

  Thereafter, when the UE 100 performs VPN cancellation with the GW 60, for example, the determination unit 32 of the UE 100 can recognize (determine) that the encryption for the second encryption interval is stopped (see FIG. 13 (7)).

  In this case, the UE 100 can notify the encryption processing unit 31 of the RNC 80 of an instruction to start (resume) encryption for the first encryption interval via, for example, the control channel. As a result, the encryption process in the first encryption section is started (FIG. 13 (8)).

As described above, when it is determined whether or not the terminal apparatus performs the encryption in the second encryption section, the terminal apparatus (UE 100 in this case) performs the encryption process in the first encryption section. It functions as a device provided with notification means for notifying a device (here, RNC 80) a standby instruction (stop instruction) for starting the encryption process and a start (resume) instruction for the encryption process.

  The processing of the encryption processing unit 31 of the RNC 80 in the example shown in FIG. 13 is the same as the processing shown in FIG. However, the standby instruction and the start (resume) instruction are received from the UE 100 notified to the RNC 80.

  On the other hand, the process of the determination part 32 in UE100 is the same as the process shown in FIG. That is, the determination unit 32 in the UE 100 monitors the negotiation (traffic) related to the encryption of the second encryption section by the second encryption processing unit 42 in OP21 and OP24, and encrypts the second encryption section. Implementation and suspension can be determined.

  If the determination unit 32 determines (detects) the execution of encryption in the second encryption interval, the determination unit 32 transmits (notifies) the RNC 80 a standby instruction to start encryption in the first encryption interval (OP23). . If it is determined (detected) that the second encryption section is stopped, an encryption start (resume) instruction for the first encryption section is transmitted (notified) to the RNC 80 (OP25). These instructions can be notified using a control link connecting the UE 100 and the RNC 80.

  In the above description, the data transfer direction (downward direction) from the server 50 to the UE 100 has been described. However, similar processing is performed in the data transfer direction (upward direction) from the UE 100 to the server 50.

By the way, as a communication path in the first encryption section, a user data communication path (DT
User channel such as CH) and communication path for control data (control channel such as DCCH)
Are independent of each other, the suspension (waiting for start) of encryption for the first encryption section is targeted only for the communication path (DCCH) for user data.

  Encryption in the first encryption section (for example, KASUMI encryption) is performed for both DTCH and DCCH. On the other hand, the IPsec encryption performed for the second encryption section targets only user data. Therefore, security for DCCH traffic can be ensured by preventing encryption for DCCH from being stopped.

FIG. 14 shows an outline of the encryption process when the DTCH as the user channel and the DCCH as the control channel are provided between the RNC 80 and the UE 100 as the first encryption section.

  As shown in FIG. 14, when the encryption process for the first encryption section is performed, the encryption process for both DTCH and DCCH traffic is performed. On the other hand, when the encryption process for the first encryption interval is stopped (stopped) by the standby instruction, only the DTCH is subject to stop, and the encryption process for the DCCH is not stopped. Therefore, the operations of FIGS. 10 (4) and 13 (4), and the processing of OP shown in FIG. 11 and OP03, OP06, and OP09 of FIG. 11 are performed only for the DTCH that is the user channel.

  In the above-described specific example, the case where the encryption method performed in the second encryption section is IPsec has been described, but another encryption method (for example, SRTP) may be used. Also, the encryption method implemented in the first encryption section is not limited to KASUMI encryption.

  Further, in the case where the wireless network control device and the device that performs encryption processing for the first encryption section are physically separated, it is determined whether or not the second encryption processing is performed. It is also possible to adopt a mode of observing. For example, this is a case where the RNC 80 includes the determination unit 32 and the base station device 90 includes the encryption processing unit 31.

  In this case, when the RNC 80 determines that the encryption of the first encryption section is not performed by monitoring the traffic of the second encryption section, the RNC 80 informs the base station device 90 that the encryption is not performed. Notice. In this case, since the base station apparatus 90 does not perform encryption in the first encryption section, the base station apparatus 90 controls the terminal apparatus (UE 100) that is opposed to not perform encryption in the first encryption section. . In addition, the encryption processing unit 31 included in the base station device 90 does not perform its own encryption processing.

<Effect of the embodiment>
According to the embodiment of the present invention, it is possible to stop encryption in the first encryption interval that overlaps with the second encryption interval in accordance with the encryption of the second encryption interval. In addition, encryption in the first encryption interval can be started (restarted) in response to the stop of encryption in the second encryption interval.

  Therefore, unnecessary encryption processing is not performed on the first encryption section. For this reason, the influence on the processing capacity of the network can be suppressed, which leads to an improvement in system capacity. For example, in the case of a cellular network (3GPP) system, not performing encryption processing can double the number of connections that can be processed. Also, the encryption process may be out of synchronization on the encryption process related to the wireless section in the first encryption section, and encryption or decryption may fail, or communication failure based on this failure may be avoided. It becomes possible. Further, by not performing the encryption process, it is possible to reduce power consumption in the apparatus that performs the encryption process.

10: Transmitting device 20: Communication device (second relay device)
21 ... Encryption / decryption processing unit 30 in the second encryption section ... Communication apparatus (first relay apparatus)
31... Encryption / decryption processing unit 32 in the first encryption section 32... Judgment unit 40 on whether to perform encryption / decryption processing in the first encryption section 40. First encryption processing unit 42 ... second encryption processing unit 50 ... server 60 ... gateway (GW)
70 ・ ・ ・ Exchange (xGSN)
80: Base station controller (RNC)
90 ... Base station device (Node B)
100 ... Terminal equipment (UE)

Claims (6)

First encryption means for performing encryption for communication in the first section between the terminal device and the first relay device;
Second encryption means for performing encryption for communication in the second section including the first section from the terminal device to the second relay apparatus via the first relay apparatus;
Control means for controlling the first encryption means so that the encryption of the first section is not performed when the encryption of the second section is performed,
The control means includes
In accordance with the second section encryption performed by the second encryption means, control the encryption performed by the first encryption means for the channel used for transmission of user data,
Controls the execution of encryption by the first encryption means regardless of whether or not the second encryption means is encrypted for the channel used for transmission of the control signal. ,
Encryption implementation control system. The said 1st encryption means will be in the state which waits for the start of the encryption of the said 1st area according to the instruction | indication notified from the said control means, when the encryption of the said 2nd area is implemented. Encryption implementation control system. 2. The control unit according to claim 1, wherein the control unit notifies the first encryption unit of an instruction to start encryption in the first section when detecting the stop of encryption performed in the second section. Encryption implementation control system. The encryption execution control system according to claim 1, wherein the control unit is provided in the first relay device or in the terminal device. The encryption execution control system according to claim 1, wherein the second encryption unit performs encryption processing using IPsec or SRTP. The first encryption means performs encryption for the user data communication path and the control data communication path in the first section,
The second encryption means encrypts user data transferred in the second section,
The first encryption unit waits for the start of encryption for the user data communication path according to an instruction from the control unit when the second section encryption is performed, while the control data The encryption execution control system according to claim 1, wherein encryption is performed for a communication channel.

Images