JPH0687234B2 - Mutual authentication method - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mutual authentication method for mutual confirmation of both parties in information communication between personal computers or information processing terminals.

2. Related Art FIG. 2 and FIG. 3 show an example of a conventional mutual authentication method relating to a typical mutual authentication method.

FIG. 2 is a diagram showing a mutual authentication system found in, for example, US Pat. No. 4,471,216. The method shown in FIG. 2 shows only one-way authentication, and therefore mutual authentication requires that both parties communicating with each other execute the method shown in FIG.

In FIG. 2, 200 and 210 are information processing devices such as personal computers, 201 is a random number generating means for generating a random number R, and 202 and 212 are first and second storing means for storing the master key km.

A method in which the information processing device 200 authenticates the information processing device 210 will be described. The information processing apparatus 200 first generates a random number R by the random number generation means 201 and transmits it to the information processing apparatus 210 that is a communication partner. In the information processing device 210, the random number R received earlier is encrypted by the second encryption means 211 using the master key km stored in the second storage means 212 (in the figure, E km [R] ′ Description), and data E km [R] 'is transmitted to the information processing device 200. On the other hand, the information processing device 20
In the same way for 0, the encryption means 203 causes the storage means 202
The random number R is encrypted by using the master key km stored in, that is, the data E km [R] is calculated, and the comparison means 20
The data E km [R] on the communication authentication side and the data E km [R] 'from the information processing device 210 are compared by 4. When they match, the information processing apparatus 200 has recognized the information processing apparatus 210. Then, this authentication enables communication between these information processing devices for the first time.

In addition to this processing, the mutual authentication method of US Pat. No. 4,471,216 consists of the information processing device 210 authenticating the information processing device 200.

Further, FIG. 3 is a diagram showing a mutual authentication method disclosed in Japanese Patent Laid-Open No. 62-120564. Even in the method shown in FIG. 3, only one-way authentication is shown. Therefore, in order to perform mutual authentication, it is necessary for both parties performing communication to execute the method shown in FIG.

In FIG. 3, 300 and 310 are information processing devices such as personal computers, 301 is a random number generation means for generating a random number R, and 303 and 312 are storage means for storing the master key km.

A method in which the information processing device 300 authenticates the information processing device 310 will be described. The information processing device 300 first generates the random number R by the random number generation means 301, and encrypts the random number R by the encryption means 302 using the master key km stored in the storage means 303, and the information processing device on the other side. Data in 310 E k
Send m [R]. In the information processing device 310, the decryption means
Master key km stored in storage means 312 by 311
The received data E km [R] is decrypted by using the random number R ′ to obtain a random number R ′, the master key km is encrypted by the encryption means 313 using this random number R ′ as a key, and the data ER ′ [ km] is transmitted.

On the other hand, the information processing apparatus 300 decrypts the data ER ′ [km] obtained from the information processing apparatus 310 by using the random number R generated by the random number generation means 301 by the decryption means 305 as a key, and the decrypted data km ′. And km stored in the storage means 303 are compared by the comparison means 304. If they match, the information processing device 300 has recognized the information processing device 310.

In addition, the mutual authentication method of Japanese Patent Laid-Open No. 62-120564 consists of the information processing device 310 authenticating the information processing device 300 in addition to this processing.

However, in the mutual authentication method shown in FIG. 2, the plaintext and the plaintext pair can be obtained from the communication line, and the plaintext selected by the decryption person is encrypted by the legitimate sender. Then, a method of deciphering the cipher by obtaining the ciphertext corresponding to the plaintext (hereinafter referred to as a selective plaintext attack) or a cipherbreaker knows some pairs of ciphertext and plaintext, and uses that knowledge. It is easy to be threatened by a method of determining a secret key by utilizing it and determining a plaintext corresponding to an arbitrary ciphertext (hereinafter referred to as a known plaintext attack). Further, in the mutual authentication method shown in FIG. 3, both parties performing communication perform encryption and decryption processing twice, respectively, resulting in a large number of processing procedures and waste of time.

Further, these two mutual authentication methods require that the data communication parties have the same key.

In view of the above point, the present invention aims to provide a mutual authentication method that prevents the above-mentioned attacks and reduces the protocol procedure.

Means for Solving the Problems The present invention for achieving the above object is a mutual authentication method when performing communication between an information processing device and an information carrier, wherein the information carrier is the information processing device side. Managed in, pre-equipped with a unique data ID and master key Km, the information carrier transmits the unique data ID pre-equipped in the information carrier to the information processing device, the information processing device Receives the unique data ID transmitted from the information carrier, and receives the unique data
Master key pre-equipped on the information carrier based on the ID
Generate the same master key as Km in the information processing device,
With this generated master key, the random session key Ks generated in the information processing device is encrypted and transmitted to the information carrier, the information carrier is transmitted by the information processing device, the master key The encrypted data of the session key Ks according to the above is decrypted by the master key Km pre-installed on the information carrier, and the decrypted data is used as a key to generate the unique data ID pre-installed on the information carrier and the information carrier. The combined data obtained by combining the random numbers is encrypted and transmitted to the information processing device, and in the information processing device, the encrypted data of the received combined data is the session key generated by the information processing device.
Decrypt using Ks, separate this decrypted data into a random number part and a data ID part, and separate this separated data ID part,
Compared with the unique data ID received as a unique data ID from the information carrier, if the comparison does not match, refuse communication from the information carrier, if matched, the separated random number part information The information carrier carries out a comparison between the separated random number portion received from the information processing device and the random number generated in the information carrier, and when the comparison is the same as the information processing device. It is characterized in that it is adapted to permit the communication of.

In the configuration of the above authentication method, the information carrier is
It is also possible to easily use the above information processing apparatus as an authentication method between two information processing apparatuses.

Action The mutual authentication method allowed by this method reduces the steps in the mutual authentication method due to the combining means and the separating means, and the pair of plaintext and codetext does not appear on the line, so that it can be used against various attacks. It is safe and enables high-security mutual authentication.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing the configuration of an embodiment of the mutual authentication system of the present invention. In this figure, 100 is an information carrier such as an IC card device, and 110 is an information processing device for center management.

The information carrier 100 transmits the unique data ID stored in the first storage means 101 to the information processing device 1 through the first transmission means 108.
Send to 10. The unique data ID is data unique to each information carrier managed by the information processing apparatus and is stored in the information carrier 100 in advance.

In the information processing device 110, the received unique data ID and the center key stored in the third storage means 111 allow the data processing means 112 to perform the master key km unique to each information carrier.
To generate. Here, it is assumed that the data processing unit 112 can generate one master key km for a certain ID by using the center key (for example, hash function).
This master key km is stored in advance in the second storage means of the information carrier 100 by the center. Key generation means 116
Generates the session key ks at random, and the second encryption means 113 encrypts the session key ks with the master key km obtained from the data processing means 112. The data encrypted by this master key ks (described as E km [ks] in the figure) is the second
Is transmitted to the information carrier 100 through the transmission means 118.

In the information carrier 100, the encrypted data E km [ks] received by the first decryption means 103 is decrypted by the master key km stored in the second storage means 102.

The first encryption means 105 encrypts the combined data from the combining means 104 using this decrypted data, that is, the session key ks as a key. The data encrypted by this ks (described as E ks [R | ID] in the figure) is transmitted to the information processing 110 through the first transmission means 108. Where the combined data E ks
[R | ID] is a unique data ID stored in the first storage means 101 and a random number R generated by the random number generation means 106, which are sequentially connected (connected).

In the information processing device 110, the second decoding means 115
The combined data E ks [R | ID] received previously is used as a key generation means.
Decrypt using the session key ks generated by 116. The separating means 114 separates the decrypted data R | ID into a random number R'and a unique data ID '. Second comparison means 117
This unique data ID 'is compared with the first received unique data ID to authenticate the information carrier 100. If the data match, the random number R ′ is transmitted to the information carrier 100 through the second transmission means 118.

If the data do not match, the information carrier 100 is rejected because there is something wrong.

In the information carrier 100, R ′ received by the first comparing means 107 and the random number R generated by the random number generating means are compared,
The information processing device 110 is authenticated. If the data do not match, the information processing apparatus 110 is rejected because there is some dishonesty.

Only when both the information carrier 100 and the information processing device 110 recognize the other party, other communication becomes possible. In data communication, the session key ks obtained by this mutual authentication method can be used.

In the mutual authentication method of the present invention, a pair of plaintext and a plaintext does not appear on the line, and selective plaintext attack and known plaintext attack cannot be performed.

Also, regarding the processing amount in the mutual authentication scheme protocol, both parties performing communication only perform encryption and decryption once, respectively.

Further, the information processing device does not need to have the master keys of all the information carriers, and the burden is reduced, and the information carriers can have their own unique master keys, which improves security.

Furthermore, since the key generated by the information processing device can be used as a session key and changes every time mutual authentication is performed, encrypted communication can be performed with high security.

Although the present embodiment has described the mutual authentication method between the information carrier such as an IC card device and the information processing apparatus managed by the center, the mutual authentication method of the present invention is, for example, information of a personal computer or the like. It can be similarly used for mutual authentication between processing devices.

EFFECTS OF THE INVENTION As described above, according to the present invention, the load on the information processing device is reduced by using the ID, and each information carrier can have a unique master key. In addition, mutual authentication can be performed by a protocol with a small processing amount that cannot perform selective plaintext attacks and known plaintext attacks. Furthermore, high security encrypted communication can be performed by using the session key.

[Brief description of drawings]

FIG. 1 is a block diagram showing a mutual authentication method of the present invention, and FIGS. 2 and 3 are block diagrams showing a conventional mutual authentication method. 100 ... Information carrier, 104 ... Combining means, 106 ... Random number generating means, 107 ... First comparing means, 110 ... Information processing device,
114 ... Separation means, 116 ... Key generation means, 117 ... Second comparison means.

Claims (4)

[Claims] 1. A mutual authentication method for communication between an information processing device and an information carrier, wherein the information carrier is a unique data ID and master key Km managed by the information processing device side. In advance, the information carrier transmits to the information processing device the unique data ID previously provided in the information carrier, the information processing device, the unique data transmitted from the information carrier Received ID and received this unique data
Master key pre-equipped on the information carrier based on the ID
Generate the same master key as Km in the information processing device,
With this generated master key, the random session key Ks generated in the information processing device is encrypted and transmitted to the information carrier, the information carrier is transmitted by the information processing device, the master key The encrypted data of the session key Ks according to the above is decrypted by the master key Km pre-installed on the information carrier, and the decrypted data is used as a key to generate the unique data ID pre-installed on the information carrier and the information carrier. The combined data obtained by combining the random numbers is encrypted and transmitted to the information processing device, and in the information processing device, the encrypted data of the received combined data is the session key generated by the information processing device.
Decrypt using Ks, separate this decrypted data into a random number part and a data ID part, and separate this separated data ID part,
Compared with the unique data ID received as a unique data ID from the information carrier, if the comparison does not match, refuse communication from the information carrier, if matched, the separated random number part information The information carrier carries out a comparison between the separated random number portion received from the information processing device and the random number generated in the information carrier, and when the comparison is the same as the information processing device. Mutual authentication method characterized by allowing communication of 2. A mutual authentication method for communication between a first information processing device and a second information processing device, wherein the second information processing device is the first information processing device. Unique data ID and master key Km managed on the server side
The second information processing apparatus transmits the unique data ID previously provided in the second information processing apparatus to the first information processing apparatus, and the first information processing apparatus The device receives the unique data ID transmitted from the second information processing device, and based on the received unique data ID, a master key Km provided in advance in the second information processing device. The same master key is generated in the first information processing apparatus, the random session key Ks generated in the first information processing apparatus is encrypted by the generated master key, and the second information processing is performed. The second information processing device, the second information processing device preliminarily provided in the second information processing device the encrypted data of the session key Ks by the master key, which was transmitted by the first information processing device. Master key K Decrypted by m, and using the decrypted data as a key, the combined data obtained by combining the unique data ID previously provided in the second information processing device and the random number generated in the second information processing device is encrypted, Transmitted to the first information processing device, and the first information processing device decrypts the received encrypted data of the combined data using the session key Ks generated in the first information processing device. Then, the decrypted data is separated into a random number part and a data ID part, and the separated data ID part is compared with the unique data ID received as the unique data ID from the second information processing device. When the comparisons do not match, the communication from the second information processing device is rejected, and when the comparisons match, the separated random number portion is transmitted to the second information processing device, and the second information processing device , The first information The separated random number portion received from the processing device is compared with the random number generated in the second information processing device, and if the comparison is matched, communication with the first information processing device is permitted. Mutual authentication method characterized in that 3. In the information processing device, the same master key as the master key included in the information carrier is generated by reading from the storage means of the information processing device that stores the same master key as the master key held by the information carrier. The mutual authentication method according to claim 1, wherein the mutual authentication method is performed by 4. In the first information processing apparatus, the same master key as the master key of the second information processing apparatus is generated by generating the same master key as the master key held by the second information processing apparatus. The mutual authentication method according to claim 2, wherein the mutual authentication method is performed by reading from a storage unit of an information processing device that stores the.