JP2004247810A - Encrypting apparatus, communication apparatus, decoder, encrypting method, decoding method, encryption program, and decoding program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an encrypting apparatus, a decrypting apparatus and a method therefor which improve the throughput of a VPN apparatus. <P>SOLUTION: In a VPN apparatus 30 for processing IPSEC authentication by an HMAC process, an encrypting apparatus 20 involved in the VPN apparatus 30 comprises a key processor 12 for first executing only a hash process of authentication key data, the hashed result (intermediate keys a, b) is stored in a database B(SAD) 8 instead of an authentication key. As a substitute for the hash process of the authentication key data repeatedly made by the HMAC process, data of the hash results (intermediate keys a, b) stored in the database B(SAD) 8 are read and used to decrease the hash process of the authentication key data to once which needed to be executed every packet to be processed for the IPSEC authentication. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an encryption device and a decryption device that authenticate a packet.
[0002]
[Prior art]
The IPSEC (IP SECURITY) processing method of the packet is “IP authentication header (AH)” in RFC (REQUEST FOR COMMENTS) 2402 according to IETF (INTERNET ENGINEERING TASK FORCE), and “IP encryption payload (ESP)” in RFC 2406. It has been described.
[0003]
An authentication processing method that must be supported when the IPSEC is implemented in the communication device is HMAC (KEYED-HASHING FOR MESSAGE AUTHENTICATION), and the authentication algorithm used for the hash function during the HMAC processing is MD5 or SHA1.
[0004]
The flow of the conventional HMAC process will be described.
First, the authentication key K is padded with 0, and is adjusted to the block size of the hash function to be used, and an exclusive OR of this and ipad is performed to generate IK1 (step 1).
Next, HMAC processing target data P is added after IK1, padding data PAD DATA and data length L are further added, and hash processing target data IP1 which is a multiple of the block size of the hash function is generated (step 2).
Next, IP1 hash processing is performed by the hash function H to generate a digest D1 (step 3).
Next, as in step 1, the authentication key K is padded with 0, the block size of the hash function to be used is used, and the pad is subjected to an exclusive OR operation with opad to generate IK2 (step 4).
Next, the digest D1 obtained as a result of step 3 is added after IK2, padding data PAD DATA and data length L are added, and hash processing target data IP2 having a size of 2 blocks of the hash function is generated ( Step 5).
Next, IP2 hash processing is performed by the hash function H to generate a digest D2. Finally, the upper 96 bits of D2 are added as an authentication digest of the IPSEC packet (step 6).
[0005]
Next, the details of the hash processing in step 3 will be described.
The hash processing is performed one block at a time using the hash initial value and the hash processing target data.
First, the hash initial value H0 defined by the hash function MD5 and the hash function SHA1 is used as the hash initial value, and a hash process of one block size is performed using the hashed data as IK1 to generate MK1 (the hash process of the key block). 1).
Next, using MK1 as a hash initial value and performing hash processing of one block size as IP1 (1) for one block behind IK1 in IP1 to generate MP1 (1) (Hash of plaintext block) Processing 1).
Next, it is determined whether or not the processing for the hash processing target data has been completed, and if there is unprocessed hash processing target data, the above-described “plain text block hash processing 1” is repeated. Here, the hash initial value in “plaintext block hash processing 1” is the result MP1 (N−1) of the previous “plaintext block hash processing 1”.
If it is determined that the processing for the data to be subjected to hash processing has been completed, MP1 (N) finally obtained is set as D1, and the processing ends.
[0006]
Next, the details of the hash processing in step 6 will be described.
Similarly to the hash processing in step 3, the hash initial value H0 defined by the hash functions MD5 and SHA1 is used as the hash initial value, and the hashed data of one block size is generated using the hashed data as IK2 to generate MK2 (key Block hash processing 2).
Next, MK2 is used as a hash initial value, hash processing of one block size is performed with the hashed data as IP2 (1), and the result is set to D2 (plaintext block hash processing 2).
[0007]
Steps 3 and 6 take time in the above hash processing, and the processing time increases in proportion to the block size of the data to be hashed.
[0008]
Next, the data length of the hash processing will be described. One block = 512 bits for both SHA1 and MD5. When hash processing is performed on certain data, padding data (1 to 512 bits) and a data length (64 bits) are added after the data to be hashed.
The padding data is for adjusting the data size obtained by combining the hash processing target data, the padding data, and the data length to a multiple of 512 bits, and the data length indicates the length of the hash processing target data before padding bits are added.
[0009]
Next, the hash processing time will be described. The time required for the hash processing is one block when the padding data and the data length of the hash processing target before adding the data length are 1 bit to 447 bits, two blocks when the data length is 448 bits to 959 (447 + 512) bits, and one block for every 512 bits thereafter. It will increase gradually.
As a result, the processing time of steps 3 and 6 of the hash processing by the authentication algorithm during the HMAC processing increases in proportion to the block size of the data length of the hash processing target.
[0010]
The HMAC processing time will be described using a short packet as an example.
When performing IPSEC authentication processing on short packets, the applicable range of HMAC processing is 448 bits for ESP and 624 bits for AH.
When HMAC processing is performed on this, two blocks are used for hash processing (Hash processing 1 for plaintext blocks) in the HMAC processing application range of the packet, and hash processing for authentication keys (Hash processing 1 for key blocks, Hash processing 2 for key blocks) ) Requires a total of 5 blocks for 2 blocks, and 1 block for hash processing for finally obtaining an authentication digest (hash processing 2 for plaintext blocks).
[0011]
The configuration on the encryption side of a generally considered VPN (VIRTUAL PRIVATE NETWORK) device will be described.
The VPN device on the encryption side realizes a user interface and a function as a local station terminal, receives a packet addressed to the local station terminal from the distribution unit, passes a packet from the local station terminal to the transmission control unit, and receives a packet from the user interface. The own station control unit that passes the set VPN setting information to the SP / SA generation unit, and the VPN setting information and the information received through mutual communication with another VPN device are received from the own station control unit. (SECURITY POLICY) data, SA (SECURITY ASSOCIATION) data, and an SP / SA generation unit that passes SP data to the reconciliation unit and SA data to the distribution unit 7; a reception unit that receives a packet; Is registered in SPD 6 (SECURITY POLICY DATABASE), and a scrutiny unit for scrutinizing the packet and SP The SPD, which is a database for storing data, and the SA data are registered in SAD (SECURITY ASSOCIATION DATABASE), packets addressed to the own station are sent to the own station control unit, packets not subject to IPSEC are sent to the transmission control unit, and packets subject to IPSEC processing are sent to A distributing unit that reads out SA data from the SAD to the encryption / authentication processing unit and passes it to the encryption / authentication processing unit, a SAD that is a database that stores the SA data, and an encryption / authentication process that performs IPSEC processing of packets A transmission control unit that controls the destination of the transmission packet received from the local station control unit, the encryption / authentication processing unit, the distribution unit, and a transmission unit that transmits the packet.
[0012]
Next, the flow of processing on the encryption side in this general VPN device will be described.
As preparation for packet processing, first, SP data and SA data are generated and registered in SPD and SAD, respectively, and then IPSEC processing of the packet is performed.
[0013]
First, in order to generate SP data and SA data, the VPN administrator sets the VPN device via the user interface of the VPN device own station terminal, and the own station control unit generates the SP / SA information received from the user interface. After the SP / SA generation unit generates the SP data, the SP / SA generation unit passes the SP data to the inspection unit, and the inspection unit registers the SP data in the SPD.
[0014]
Next, in order to construct a VPN between the devices, the devices communicate with each other to generate SA data. The SP / SA generation unit passes the data addressed to the other VPN device for determining the SA data to the own station control unit, and the own station control unit packetizes this and sends it to the transmission control unit. And the transmitting unit transmits this to the outside of the device. The receiving unit passes a received packet having information for determining SA data from another VPN device to the reconciliation unit, which passes the received packet to the distribution unit, and the distribution unit determines that the packet is addressed to the own station. The self-station control unit passes this to the SP / SA generation unit.
When the SA data is determined by the above communication, the SP / SA generation unit passes the SA data to the distribution unit, and the distribution unit registers this in the SAD.
[0015]
Next, the receiving unit receives the IPSEC processing target packet and passes it to the scrutinizing unit. The inspection unit determines that the packet is to be subjected to the IPSEC process based on the source address, the destination address, the protocol, and the port number of the packet header, and reads out the SPI (SECURITY PARAMETER INDEX) corresponding to the packet from the SPD, This and the packet are passed to the distribution unit. The distribution unit refers to the SAD based on the SPI and passes SA data such as an encryption algorithm, an authentication algorithm, an encryption key, and an authentication key to the encryption / authentication processing unit.
The encryption / authentication processing unit performs IPSEC processing of the packet based on the processing information included in the SA data, and passes the processed packet to the transmission control unit. Here, when the process indicated by the SA data includes an authentication process, the encryption / authentication processing unit performs the HMAC process on the packet. The transmission control unit determines that the packet received from the encryption / authentication processing unit is addressed to another VPN device, and passes the packet to the transmission unit. The transmitting unit transmits the packet out of the device (for example, see Patent Document 1).
[0016]
[Patent Document 1]
JP-A-11-8620
[0017]
[Problems to be solved by the invention]
In the case of the VPN device configuration as described above, all the HMAC processing is performed by the encryption / authentication processing unit. In the HMAC processing, there is a hash processing part that does not require packet data but requires authentication key data (key block hash processing 1 and key block hash processing 2). This is HMAC key processing.
When there are a plurality of packets using the same authentication key, the HMAC key processing is executed for each packet, so that there is a problem that it takes time and is inefficient.
[0018]
An object of the present invention is to provide an encryption device, a decryption device, and a method for improving the throughput of a VPN device.
[0019]
[Means for Solving the Problems]
The encryption device according to the present invention comprises:
A key processing unit that generates an intermediate key from predetermined data related to the key,
A database for storing an intermediate key generated by the key processing unit,
An encryption / authentication processing unit that encrypts a message included in the packet and authenticates the encrypted message using the intermediate key stored in the database as an authentication key.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1 FIG.
Embodiment 1 will be described.
FIG. 1 is a system configuration diagram of a VPN device 30 showing the invention of the first embodiment. The VPN device 30 is an example of a communication device in which a communication function and an interface function are added to the encryption device 20 of the present invention.
In FIG. 1, a local station control unit 2 realizes a function as a local station terminal, receives a packet addressed to the local station terminal from a distribution unit 7, passes a packet from the local station terminal to a transmission control unit 10, and This is a unit that passes the VPN setting information set from the interface 1 to the SP / SA generating unit 3.
The SP / SA generation unit 3 receives from the own station control unit 2 the VPN setting information and the information received through mutual communication with other VPN devices, generates SP data and SA data from these information, and converts the SP data. A unit that passes the authentication key of the SA data to the key processing unit 12 and passes the data after the HMAC key processing received from the key processing unit 12 to the reconciliation unit 5 as a part of the SA data. is there. Hereinafter, the data after the HMAC key processing received from the key processing unit 12 is referred to as an intermediate key. The HMAC key processing will be described later.
[0021]
The receiving unit 4 receives the packet, and the scrutinizing unit 5 registers the SP data in the database A (SPD) 6 and scrutinizes the packet received by the receiving unit 4. Therefore, the database A (SPD) 6 stores the SP data.
The distribution unit 7 registers the SA data in the database B (SAD) 8, encrypts and authenticates a packet addressed to the own station to the own station control unit 2, a packet not subject to IPSEC to the transmission control unit 10, and a packet subject to IPSEC processing. The SA unit reads the SA data from the database B (SAD) 8 and passes it to the encryption / authentication processing unit 9 at this time. Therefore, the database B (SAD) 8 is a database that stores SA data, and is an example of a database that stores an intermediate key generated by a key processing unit described below.
The encryption / authentication processing unit 9 performs IPSEC processing on the packet, encrypts the message included in the packet, and authenticates the encrypted message using the intermediate key stored in the database as an authentication key.
The transmission control unit 10 controls the destination of the transmission packet received from the own station control unit 2, the encryption / authentication processing unit 9, and the distribution unit 7, and the transmission unit 11 is a unit that transmits the packet.
The key processing unit 12 is a unit that performs HMAC key processing of the authentication key received from the SP / SA generation unit 3, generates an intermediate key, and transfers this to the SP / SA generation unit. That is, the key processing unit 12 generates an intermediate key from predetermined data related to the key (the authentication key received from the SP / SA generation unit 3).
The encryption device 20 includes the key processing unit 12 and the encryption / authentication processing unit 9, and may store the database B (SAD) 8 internally or externally.
[0022]
Next, a processing flow of the VPN device 30 of the present invention in the present embodiment will be described with reference to FIG. As preparation for packet processing, first, SP data and SA data are registered, and then IPSEC processing of the packet is performed.
[0023]
First, in order to generate SP data and SA data, the VPN administrator sets the VPN device 30 through the user interface 1 of the VPN device own station terminal, and the own station control unit 2 transmits the information received from the user interface 1 Is passed to the SP / SA generating unit 3, which generates SP data which is setting data of the VPN device 30 (T 1), and then passes it to the scrutinizing unit 5, which parses the SP data into a database. A (SPD) 6 is registered (T2).
[0024]
Next, in order to construct a VPN between the VPN devices, the VPN devices mutually communicate with other VPN devices to generate SA data. The SP / SA generation unit 3 passes data addressed to another VPN device for determining SA data to the own station control unit 2, and the own station control unit 2 packetizes the data and passes it to the transmission control unit 10, and performs transmission control. The unit 10 passes it to the transmission unit 11, which transmits this to the outside of the device.
The receiving unit 4 passes a received packet having information for determining SA data from another VPN device to the scrutinizing unit 5, and the scrutinizing unit 5 passes the packet to the allocating unit 7. This packet is passed to the SP / SA generation unit 3. When the SA data is generated and determined (T3) by the above communication, the SP / SA generating unit 3 passes the authentication key of the SA data to the key processing unit 12, and the key processing unit 12 performs the HMAC key processing (the key (Y1 in FIG. 2) ) Hash processing 1: T4, hash processing of the key (Z1) 2: indicated by T5), and the obtained intermediate key is passed to the SP / SA generation unit 3.
The SP / SA generation unit 3 passes the SA data to the distribution unit 7, and the distribution unit 7 registers this in the database B (SAD) 8 (T6).
[0025]
The receiving unit 4 receives the packet to be subjected to the IPSEC processing (T7) and passes the packet to the scrutinizing unit 5.
The scrutinizing unit 5 determines that this packet is to be subjected to IPSEC processing, reads out the SPI corresponding to this packet from the database A (SPD) 6, and passes this and the packet to the distribution unit 7. The distribution unit 7 reads out SA data from the database B (SAD) 8 based on the SPI (SECURITY PARAMETERS INDEX), and passes this and the packet to the encryption / authentication processing unit 9.
The encryption / authentication processing unit 9 performs IPSEC processing of the packet based on the processing information included in the SA data, and passes the processed packet to the transmission control unit 10.
Here, if the process indicated by the SA data includes an authentication process, the encryption / authentication processing unit 9 performs the HMAC process on the message included in the packet ((in FIG. 2, hash process 1: T8 of message (Y2), Message (Z2) hash processing 2: indicated by T9).
The transmission control unit 10 determines that the packet received from the encryption / authentication processing unit 9 is addressed to another VPN device, and passes the packet to the transmission unit 11. The transmitting unit 11 transmits the packet to outside the device.
[0026]
Next, hash processing 1 (HMAC key processing) of the key (Y1) indicated by T4 in FIG. 2 will be described with reference to FIG.
First, the key processing unit 12 pads the authentication key K with 0, matches the block size of the hash function to be used, and performs an exclusive OR of this and ipad to generate IK1 (Y0).
Next, the key processing unit 12 generates MK1 that is the intermediate key a. The hash initial value H0 defined by the hash function MD5 and the hash function SHA1 is used as the hash initial value, and the data to be hashed is subjected to the hash processing of one block size using the IK1 generated at the above Y0, MK1 (intermediate key a) is generated (Y1).
[0027]
Next, hash processing 2 (HMAC key processing) of the key (Z1) indicated by T5 will be described with reference to FIG.
In Z0, the key processing unit 12 performs padding of the authentication key K with 0 in the same manner as in Y0, performs an exclusive OR operation of the padding with the block size of the hash function to be used and opad, and generates IK2.
Next, the key processing unit 12 generates the MK2 that is the intermediate key b, as in the hash processing 1 of the key (Y1). The hash initial value H0 defined by the hash functions MD5 and SHA1 is used as the hash initial value, and hash processing of one block size is performed using the hashed data as IK2 to generate MK2 (intermediate key b).
[0028]
FIG. 5 shows the structure of the database A (SPD) 6 and the database B (SAD) 8 on the encryption side of the VPN device 30 according to the present embodiment.
In the HMAC key processing, the key processing unit 12 uses the data (MK1) after the processing of Y1 as the intermediate key a and the data (MK2) after the hash processing 2 of the key (Z1) as the intermediate key b, and uses the intermediate keys a, The intermediate key b is registered in the database B (SAD) 8 as an authentication key by the distribution unit 7. The intermediate key a and the intermediate key b are keys registered instead of the conventional authentication key.
[0029]
Next, the process of T8 shown in FIG. 2 will be described.
FIG. 6 shows the processing performed in the hash processing 1 (T8) of the message (Y2). First, the encryption / authentication processing unit 9 adds HMAC processing target data P after IK1 at Y20, further adds padding data PAD DATA and data length L, and performs hash processing that is a multiple of the block size of the hash function. The target data IP1 is generated.
Next, the encryption / authentication processing unit 9 performs hash processing of one block size by using MK1 (intermediate key a) as a hash initial value and using the data to be hashed as IP1 (1) for one block behind IK1 in IP1. Generate MP1 (1). Next, it is determined whether or not the processing for the hash processing target data has been completed (Y24). If there is unprocessed hash processing target data, the above-described processing of Y22 is repeated. Here, the hash initial value in Y22 is the result MP1 (N-1) of the previous Y22.
If it is determined that the processing for the hash processing target data has been completed (Y24), the process ends with the finally obtained MP1 (N) as D1.
[0030]
Next, the process of T9 shown in FIG. 2 will be described.
FIG. 7 shows a process performed in the hash process 2 (T9) of the message (Z2). First, the encryption / authentication processing unit 9 adds the digest D1 obtained as a result of T8 after IK2 in Z20, further adds padding data PAD DATA and data length L, and the size becomes two blocks of the hash function. Generate the hash processing target data IP2.
Next, in Z22, the encryption / authentication processing unit 9 performs hash processing of one block size using MK2 (intermediate key b) as a hash initial value and IP2 (1) as hashed data, and digests the result. D2.
Finally, the upper 96 bits of the digest D2 are added as an authentication digest of the IPSEC packet.
[0031]
As described above, in the VPN device 30 that performs the IPSEC authentication process by the HMAC process by the encryption device 20, the key processing unit 12 that first executes only the hash process for the authentication key data is provided, and the hashed result (intermediate key a, intermediate key b ) Is stored in the database B (SAD) 8 instead of the authentication key, and the hash result data (intermediate data) stored in the database B (SAD) 8 is used instead of repeatedly performing the hash processing of the authentication key data in the HMAC processing. By reading and using the key a and the intermediate key b), the HMAC process can be performed at a high speed by performing the hash process of the authentication key data, which had to be executed for each packet to be subjected to the IPSEC authentication process, only once. A VPN device characterized in that IPSEC authentication processing can be performed at high speed by being able to perform And it describes.
[0032]
As described above, the encryption device 20 included in the VPN device 30 includes a key processing unit 12 that generates an intermediate key from predetermined data related to a key, and a database (database B (database B) that stores the intermediate key generated by the key processing unit 12. SAD) 8), encrypts the message contained in the packet, and uses the intermediate key stored in the database (database B (SAD) 8) as an authentication key, and substitutes the intermediate key into a hash function to encrypt the message. And an encryption / authentication processing unit 9 for authenticating the encrypted message.
[0033]
Then, the encryption device 20 performs packet communication by VPN (VIRTUAL PRIVATE NETWORK) by performing communication of a packet including the message authenticated by the encryption / authentication processing unit 9 in accordance with the IPSEC protocol (IP SECURITY PROTOCOL). .
[0034]
The communication device (VPN device 30) of the present embodiment generates an intermediate key by the key processing unit 12 of the encryption device 20 and a database (database B (SAD) that stores the intermediate key generated by the key processing unit 12). 8) and an encryption / authentication processing unit 9 for encrypting the message included in the packet and authenticating the encrypted message using the intermediate key stored in the database (database B (SAD) 8) as an authentication key. And a transmission unit 11 for transmitting a packet including a message authenticated by the encryption / authentication processing unit 9.
[0035]
In the VPN device configured as described above, the HMAC key processing is performed by the key processing unit 12 at the time of SA data registration, and therefore does not need to be performed by the encryption / authentication processing unit 9.
The above-described HMAC key processing corresponds to the hash processing 1 (T4) of the key (Y1) and the hash processing 2 (T5) of the key (Z1) in FIG. 2, and requires a total of two blocks. The intermediate key (intermediate key a, intermediate key b) generated by the HMAC key processing unit instead of the conventional authentication key is used as a part of the SA data, and the SP / SA generation unit 3 passes the SA data to the distribution unit 7. , The distribution unit 7 registers this in the database B (SAD) 8. By using the intermediate key, the encryption / authentication processing unit 9 can reduce the number of blocks by two for each packet authentication process.
[0036]
Embodiment 2 FIG.
Although the key processing unit 12 is provided in the first embodiment, access to the database B (SAD) 8 is transferred from the distribution unit 7 to the encryption / authentication processing unit 9 as shown in FIG. The unit 7 passes the SA data to the encryption / authentication processing unit 9, and the encryption / authentication processing unit 9 performs HMAC key processing. After that, the encryption / authentication processing unit sends the SA data including the intermediate key to the database B (SAD) 8. By registering, it is also possible to realize the present invention without providing the key processing unit 12.
[0037]
As described above, in the present embodiment, by configuring the system as shown in FIG. 8, only the hash processing for the authentication key data is performed first at the time of registration in the database B (SAD) 8, and the hashed result (intermediate The key a and the intermediate key b) are stored in the database B (SAD) 8 instead of the authentication key, and are stored in the database B (SAD) 8 instead of repeatedly performing the hash processing of the authentication key data in the HMAC processing. By reading and using the data of the hash result (intermediate key a and intermediate key b), the hash processing of the authentication key data, which had to be executed for each packet to be subjected to the IPSEC authentication processing, can be performed only once. As a result, the HMAC process can be performed at a high speed, so that a VPN device that can perform the IPSEC authentication process at a high speed can be constructed.
[0038]
As described above, the encryption device 20 included in the VPN device 30 according to the present embodiment generates an intermediate key from a database (database B (SAD) 8) that stores information about keys and predetermined data about keys. The generated intermediate key is stored in the database (database B (SAD) 8), a message included in the packet is encrypted, and the intermediate key stored in the database (database B (SAD) 8) is repeatedly used as an authentication key. And an encryption / authentication processing unit 9 for authenticating the message.
[0039]
Embodiment 3 FIG.
As another embodiment, it is conceivable to provide an area for storing an intermediate key in the encryption / authentication processing unit 9.
FIG. 9 shows this embodiment. The encryption / authentication processing unit 9 has an intermediate key memory 15 therein, stores the intermediate key in the intermediate key memory 15 at the time of the first packet authentication processing for a certain authentication key, and thereafter stores the intermediate key in the packet authentication processing using the same key. By reading the key from the intermediate key memory 15 and using it, the same effect as in the first and second embodiments can be obtained.
[0040]
As described above, in the present embodiment, by configuring the system as shown in FIG. 9, the area (intermediate key memory 15) for storing the hash processing result (intermediate key a and intermediate key b) for the authentication key data is provided. The intermediate key (the intermediate key a and the intermediate key b) stored in the intermediate key memory 15 during the first packet authentication with a certain authentication key and read and used during the subsequent packet authentication processing. The HMAC process can be performed at a high speed by performing the hash process of the authentication key data, which has to be performed for each packet to be subjected to the IPSEC authentication process, only once. A high-speed VPN device can be constructed.
[0041]
As described above, the encryption device 20 included in the VPN device 30 of the present embodiment generates an intermediate key from predetermined data related to the key, encrypts the message included in the first packet of the plurality of packets, and generates the intermediate key. Authenticates the message encrypted using the intermediate key and stores the generated intermediate key in the intermediate key memory 15, encrypts the message included in the packets other than the first packet of the plurality of packets, An encryption / authentication processing unit 9 for performing authentication by repeatedly using the intermediate key stored in the key memory 15 is provided.
[0042]
Effects obtained in all the above-described embodiments will be described.
FIG. 10 shows a comparison of the HMAC processing time between the general VPN device and the VPN device of the invention according to all the above-described embodiments when performing the IPSEC authentication process on the short packet.
As shown in FIG. 10, the time required for completing the first packet processing based on certain SA data is almost the same as that of the conventional method. However, for the second and subsequent packets, the processing time is reduced by two blocks for each packet, and when N packets are processed, the time is reduced by 2 (N-1) blocks. FIG. 10 shows a case of a short packet as an example, but the effect is the same when a packet of other length is processed.
[0043]
The encryption-side VPN devices in all of the above embodiments can be applied to the decryption-side VPN device. In the decryption-side VPN device, of the IPSEC process, the authentication processing procedure is the same as that of the encryption-side, so that the same effect can be realized.
[0044]
That is, in the flow of the IPSEC process, an authentication processing unit is provided after the encryption processing unit in the encryption apparatus, and the authentication processing unit performs authentication processing on the data after the encryption processing. On the other hand, in the decryption device, there is a decryption processing unit after the authentication processing unit, and the decryption processing is performed after the authentication processing unit performs the authentication processing. Here, since the authentication processing units on the encryption side and the decryption side are the same, the authentication processing procedure according to the inventions of all the above embodiments can be used on the decryption side. Are the same, the same effect as the encryption device can be realized in the decryption device.
[0045]
In addition, the inventions of all the above embodiments can be applied to both SHA1 and MD5 without depending on the authentication algorithm used in the HMAC, and can also be applied to authentication algorithms of other block sizes. .
[0046]
Further, in the inventions in all of the above embodiments, a VPN device is given as an example of a communication device, but the present invention is also effective when implemented by software.
[0047]
FIG. 11 is a computer basic configuration diagram of the communication device in all of the above embodiments.
In FIG. 11, a CPU 40 that executes a program is connected to a monitor 41, a keyboard 42, a mouse 43, a communication port 44, a magnetic disk device 46, and the like via a bus 38.
The magnetic disk device 46 stores an OS 47, a program group 49, and a file group 50. However, an embodiment in which the program group 49 and the file group 50 are integrated to form the object-oriented program group 49 is also considered as one embodiment.
The operations performed by the key processing unit 12, the encryption / authentication processing unit 9, and the like can be described as a program. When these programs 49 are stored in the magnetic disk device 46 and executed by the CPU 40 using the OS 47, the operations performed by the key processing unit 12, the encryption / authentication processing unit 9, and the like can be implemented by software. Can be.
In each of the above embodiments, the communication device communicates with another communication device using the function of the communication port 44.
[0048]
The terms “register” and “store” described above mean that the information is stored in a recording medium.
[0049]
In all embodiments, each operation of each component is related to each other, and the operation of each component can be replaced as a series of operations while taking into account the relation of the operations described above. Then, by substituting in this way, an embodiment of the method invention can be obtained.
Further, by replacing the operation of each of the above components with the processing of each of the components, an embodiment of a program can be realized.
In addition, by storing the program on a computer-readable recording medium on which the program is recorded, an embodiment of a computer-readable recording medium on which the program is recorded can be provided.
[0050]
The embodiment of the program and the embodiment of the computer-readable recording medium recorded in the program can all be configured by a computer-operable program.
Each process in the embodiment of the program and the embodiment of the computer-readable recording medium on which the program is recorded is executed by the program, and the program is recorded in the recording device, and is transmitted from the recording device to the central processing unit ( CPU) and each flowchart is executed by the central processing unit.
Also, the software and programs of each embodiment may be implemented by firmware stored in a ROM (READ ONLY MEMORY). Alternatively, each function of the above-described program may be realized by a combination of software, firmware, and hardware.
[0051]
【The invention's effect】
As described above, according to the present invention, the processing time of the entire apparatus in the IPSEC authentication processing is reduced, and the improvement of the throughput is measured.
[Brief description of the drawings]
FIG. 1 is a block diagram of a VPN device according to a first embodiment of the present invention.
FIG. 2 is an IPSEC authentication processing flow in the VPN device according to the first embodiment of the present invention.
FIG. 3 is a flowchart of MK1 (intermediate key a) generation.
FIG. 4 is a flowchart of MK2 (intermediate key b) generation.
FIG. 5 is a structural diagram of each database.
FIG. 6 is a flowchart showing a flow of an HMAC process.
FIG. 7 is a flowchart showing a flow of an HMAC process.
FIG. 8 is a block diagram of a VPN device according to a second embodiment of the present invention.
FIG. 9 is a block diagram of a VPN device according to a third embodiment of the present invention.
FIG. 10 is a diagram showing a difference between the effects of the HMAC process in a general VPN device and the VPN devices of the invention according to all the embodiments.
FIG. 11 is a basic configuration diagram of a computer of the communication device.
[Explanation of symbols]
1 user interface, 2 own station control unit, 3 SP / SA generation unit, 4 reception unit, 5 scrutiny unit, 6 database A (SPD), 7 distribution unit, 8 database B (SAD), 9 encryption / authentication processing unit , 10 transmission control section, 11 transmission section, 12 key processing section, 15 intermediate key memory, 38 bus, 40 CPU, 41 monitor, 42 keyboard, 43 mouse, 44 communication port, 46 magnetic disk drive, 47 OS, 49 program group , 50 files.

Claims (12)

A key processing unit that generates an intermediate key from predetermined data related to the key,
A database for storing an intermediate key generated by the key processing unit,
An encryption device comprising: an encryption / authentication processing unit that encrypts a message included in a packet and authenticates the encrypted message using an intermediate key stored in the database as an authentication key. A database for storing information about the key;
An intermediate key is generated from predetermined data related to the key, the generated intermediate key is stored in the database, the message included in the packet is encrypted, and the message is repeatedly used by using the intermediate key stored in the database as an authentication key. An encryption device including an encryption / authentication processing unit for performing authentication. 3. The encryption device according to claim 1, wherein the encryption / authentication processing unit authenticates a message included in a plurality of packets by repeatedly using the intermediate key stored in the database. Generating an intermediate key from predetermined data relating to the key; encrypting a message included in the first packet of the plurality of packets; authenticating the encrypted message using the generated intermediate key; An encryption / authentication processing unit for storing in a key memory, encrypting a message included in a packet other than the first packet of the plurality of packets, and performing authentication by repeatedly using the intermediate key stored in the intermediate key memory; Encryption device. The encryption device according to claim 1, wherein the encryption / authentication processing unit authenticates a message by substituting the intermediate key into a hash function. 2. The packet communication device according to claim 1, wherein the encryption device performs packet communication by VPN (VIRTUAL PRIVATE NETWORK) by performing communication of a packet including the message authenticated by the encryption / authentication processing unit in accordance with an IPSEC protocol (IP SECURITY PROTOCOL). Alternatively, the encryption device according to claim 2 or 4. A key processing unit that generates an intermediate key from predetermined data related to the key,
A database for storing an intermediate key generated by the key processing unit,
An encryption / authentication processing unit that encrypts the message included in the packet and authenticates the encrypted message using the intermediate key stored in the database as an authentication key;
A communication device comprising: a transmission unit that transmits a packet including a message authenticated by the encryption / authentication processing unit. A key processing unit that generates an intermediate key from predetermined data related to the key,
A database for storing an intermediate key generated by the key processing unit,
A decryption device comprising: a decryption / authentication processing unit that decrypts a message included in a packet and repeatedly authenticates the decrypted message by repeatedly using the intermediate key stored in the database as an authentication key. Generate an intermediate key from predetermined data on the key,
The generated intermediate key is stored in a database,
An encryption method for encrypting a message included in a packet and authenticating the encrypted message using an intermediate key stored in the database as an authentication key. Generate an intermediate key from predetermined data on the key,
The generated intermediate key is stored in a database,
A decryption method for decrypting a message included in a packet and authenticating the decrypted message by repeatedly using the intermediate key stored in the database as an authentication key. A process of generating an intermediate key from predetermined data related to the key;
Processing for storing the generated intermediate key in a database;
An encryption program for encrypting a message included in the packet and authenticating the encrypted message using the intermediate key stored in the database as an authentication key. Generating an intermediate key from predetermined data related to the key;
Processing for storing the generated intermediate key in a database;
A decryption program for causing a computer to execute a process of decrypting a message included in a packet and repeatedly using the intermediate key stored in the database as an authentication key to authenticate the decrypted message.

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