JPH07170256A - Communicating party authenticating method and cipher communication equipment using the same method - Google Patents

Abstract

PURPOSE:To provide a communicating party authenticating method capable of surely authenticating a communicating party even when a communication path is not safe and a cipher equipment using the method. CONSTITUTION:An entity A prepares information M from the IDs of the entity A and the entity B and random numbers, prepares the information KAB (M) by converting the information M by prescribed algorithm by an arithmetic part using a cryptographic key with the entity B among the pairs of the cryptographic keys held in the memory part of its own, requests communication to the entity B and simultaneously transmits the information kAM (M). The entity B prepares inversely converted information kAB<-1>{kAB(M)} by inversely converting the information kAN (M) received from the entity A using the cryptographic key with the entity A among the pairs of the cryptographic keys held in the memory part of its own and discriminates whether or not the IDs of the entity A and the entity B are obtained from the inversely converted information kAB<-1>{kAB(M)}.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication partner authentication method and a cryptographic communication device using the method, and in particular, when a communication using a cipher is started, a caller or a callee confirms the communication partner. The present invention relates to a communication partner authentication method that can be performed, and a cryptographic communication device using the method.

[0002]

2. Description of the Related Art Conventionally, as a caller authentication method, there is a method of displaying identification information (hereinafter referred to as ID) of a caller communication device or a caller on a callee communication device.
For example, it comprises at least one center and a plurality of entities, and the center distributes to each entity a pair of encryption keys corresponding to its identification information, and each entity keeps the distributed pair of encryption keys secret. Conventionally, a communication partner authentication method in a network, which includes a memory means for doing so and a calculation means for executing a predetermined algorithm, has been used.

With regard to the callee authentication, in the encrypted communication, the contents of the encrypted communication can be known only to the designated party. Therefore, little research has been done on the method of authenticating the called party.

[0004]

However, in the above-mentioned conventional caller authentication method, when the communication line is not safe, the ID of another person can be easily given, and the caller authentication cannot be surely performed. There is. Also in the caller authentication, even if the callee is simply specified using the encryption key, the same problem as in the caller authentication described above occurs when the communication line is not secure.

The present invention has been made in order to solve the above problems, and provides a communication partner authentication method capable of reliably authenticating a communication partner even when the communication path is not secure, and an encryption device using the method. With the goal.

[0006]

In order to achieve the above object, the first invention of the present invention comprises at least one center and a plurality of entities, and the center responds to each entity with its identification information. A method for authenticating a communication partner in a network, which distributes a set of encryption keys, and each entity includes a memory unit for holding the distributed set of encryption keys secretly and an operation unit for executing a predetermined algorithm. In the above, when performing communication between the first entity and the second entity among the plurality of entities, one of the first and second entities stores information created from the identification information of both entities and a random number. Using the encryption key with the other entity of the encryption key set held in the memory means of the operator, the operator By the predetermined algorithm and sends the conversion information to the other entity, and the other entity encrypts with the one entity of the pair of encryption keys held in its own memory means. The conversion information is inversely converted by the arithmetic means using a key, it is determined whether or not the identification information of each of the first and second entities is obtained from the inverse conversion information, and the communication partner is identified based on the determination result. It is characterized by being authenticated.

A second aspect of the present invention comprises at least one center and a plurality of entities, wherein the center distributes to each entity a set of encryption keys corresponding to its identification information, and each entity distributes said entity. A method of authenticating a communication partner in a network, comprising: a memory means for holding a set of encryption keys secretly; and a computing means for executing a predetermined algorithm. When communicating between two entities, one of the first and second entities sets the encryption key set held in its own memory means with information created from identification information of both entities and a random number. By using the encryption key with the other entity of the The conversion information is sent to the other entity, and the other entity uses the conversion information and the encryption key of the one entity of the pair of encryption keys held in the memory means of the other entity to perform the conversion. It is characterized in that information is compared with information converted by the predetermined algorithm by the arithmetic means, and a communication partner is authenticated based on the comparison result.

A third aspect of the present invention is an encryption communication device using the communication partner authentication method according to any one of the first and second aspects of the invention, wherein a random number included in the creation information is used as the encryption key. It is characterized by using.

A fourth aspect of the present invention is an encrypted communication device using the communication partner authentication method according to any one of the first and second aspects of the invention, wherein the random number included in the creation information and the encryption key are included. It is characterized in that a combination of the above is used as an encryption key.

[0010]

According to the communication partner authentication method of the first invention, the other entity reversely transforms the conversion information received from the one entity by using the encryption key of the one entity, and the inverse conversion information. If the communication signal is not safe, since it is determined whether the identification signals of both the entities are obtained from the above, and whether the conversion information is genuinely created by one of the entities based on the determination result. However, it is possible to realize accurate caller / callee authentication.

According to the communication partner authentication method of the second invention, the other entity compares the conversion information received from the one entity with the conversion information newly created by the same procedure as the conversion information. Then, since it is determined whether or not one of the entities has created the conversion information based on the comparison result, it is possible to realize accurate caller / callee authentication even when the communication path is not secure. .

Further, according to the encrypted communication device of the third or fourth invention, in the communication partner authentication method according to the first or second invention, a random number created by a random number generator, or By using a combination of a random number and an encryption key by a predetermined algorithm as the encryption key, it is possible to change the encryption key for each communication even between the same sender and receiver.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] FIG. 1 is a block diagram of a communication network for carrying out a communication partner authentication method according to a first embodiment of the present invention, and particularly shows a state of distribution of an encryption key.
In the figure, A, B, C, ..., N are IDs of the respective entities, and GA, GB, ..., GN are sets of encryption keys distributed from the center to the respective entities A, B ,.
Also, kAB, ..., kAN, kAB, ..., kBN, kA
N, ..., kN-1N are encryption keys, for example,
kAB is an encryption key between entity A and entity B,
kAN represents an encryption key of the entity A and the entity N.

The center distributes to each entity a set of encryption keys corresponding to the ID of the entity in advance. The distribution of the encryption key shown in FIG. 1 is the same in the following embodiments.

FIG. 2 is a block diagram showing the configuration of each entity in this embodiment. In the figure, reference numeral 1 denotes a memory unit, which keeps a set of encryption keys distributed to the entity secretly, and cannot access data from the outside. Reference numeral 2 denotes an arithmetic unit, which performs arithmetic using an algorithm uniquely determined by the communication network to which the entity belongs, and converts information created from each ID of the entity concerned and the entity of the communication partner and a random number from a random number generator (not shown). To do. Reference numeral 3 denotes a circuit for requesting communication, which is for requesting communication when the entity concerned wants to communicate with another entity. The entity secretly holds the set of unique encryption keys distributed from the center to the memory unit 1.

FIG. 3 shows the present embodiment for sender authentication in which a receiver of communication (hereinafter referred to as entity B) authenticates a sender (sender: hereinafter referred to as entity A) when performing communication. It is a figure which shows the communication procedure which concerns.

(Procedure 1) As shown in FIG. 3, when the entity A wants to communicate with the entity B, the entity A generates its own ID, the ID of the entity B as a communication partner, and a random number generator. The message information M is created from the generated random number.

(Procedure 2) Next, the entity A inputs the ID of the entity B into the memory unit 1 of FIG. 2, and encrypts the entity B with the encryption key set stored in the memory unit 1. Call the key kAB. Entity A
Using the encryption key kAB, the arithmetic unit 2 of FIG.
Information kAB (M) is obtained by converting information M by the above algorithm.
And makes a request for communication to the entity B via the circuit 3, and at the same time transmits the information kAB (M).

(Procedure 3) The entity B, which has received the communication request and the information kAB (M) from the entity named A, inputs the ID of the entity A into the memory unit 1 and is secretly distributed from the center. The encryption key kAB with the entity A from the encryption key set stored in
Call. Next, using the encryption key kAB, the calculation unit 2
The information kAB (M) is inversely converted by means of, and it is determined whether or not the IDs of the entity A and the entity B can be obtained from the obtained inverse conversion information kAB ^-1 (kAB (M)). The I
Once D is obtained, the originator of the communication request is entity A
To authenticate. By this method, even if the communication path is not secure, the caller can be authenticated accurately.

[Second Embodiment] Next, a second embodiment of the present invention will be described with reference to FIGS. 4 and 5.

FIG. 4 is a diagram showing a communication procedure according to the present embodiment for originator authentication in which the called party authenticates the sender when performing communication in the same environment as the first embodiment.

FIG. 5 is a block diagram showing the configuration of each entity according to this embodiment. In the figure, reference numeral 4 denotes a comparator, which determines whether two pieces of information are the same. 1,
Reference numerals 2 and 3 respectively denote a memory unit, an arithmetic unit, and a communication requesting circuit, which are similar to those in FIG.

(Procedure 1) As shown in FIG. 4, when the entity A wants to communicate with the entity B, the entity A makes a communication request to the entity B by the communication request circuit 3 shown in FIG. .

(Procedure 2) The entity B which has received the communication request from the entity named A has its own ID and
The message information M is created from the ID of the entity A and the random number generated by the random number generator.
Send to.

(Procedure 3) The entity A inputs the ID of the entity B into the memory unit 1 of FIG. 5, and selects the encryption key kAB with the entity B from the set of the encryption keys held in the memory unit 1. Call. Next, the encryption key kAB
5 is converted into the information kAB by the calculation unit 2 in FIG. 5 by the algorithm defined in the network.
Create (M) and send again to entity B.

(Procedure 4) The entity B having received the information kAB (M) stores the ID of the entity A in the memory unit 1.
, And calls the encryption key kAB with the entity A from the set of the encryption keys held in the memory unit 1. Next, the information kAB (M) is inversely converted by the calculation unit 2 by the above algorithm using the encryption key kAB, and the obtained inverse conversion information kAB ^-1 (kAB (M)) and the entity B in step 2 are used. The information M newly created by the same method as described above is compared by the comparator 4 of FIG. 5, and if the two are the same, the sender of the communication request is authenticated as the entity A.

With this method, even if the communication path is not secure, the caller can be authenticated accurately.

[Third Embodiment] Next, a third embodiment of the present invention will be described with reference to FIG.

FIG. 6 shows the same environment as in the first embodiment.
It is a figure which shows the communication procedure which concerns on a present Example for caller authentication in which a callee authenticates a sender at the time of performing communication. The procedure of the communication method according to the present embodiment is different from that of the second embodiment only in procedure 4, and will be described below as procedure 4 '. Since the configuration of each entity in this embodiment is the same as that in the second embodiment, FIG. 5 can be applied as it is.

(Procedure 4 ') As shown in FIG. 6, information kA
The entity B that has received B (M) is
Of the encryption key k stored in the memory unit 1 and the encryption key k with the entity A.
Call AB. Next, step 3 is performed using the encryption key kAB.
And the information kAB (M) sent back from the entity A, with the information M converted in the same way as in
Are compared by the comparator 4 of FIG. 5, and if they are the same, the sender of the communication request is authenticated as the entity A.

By this method, even if the communication path is not secure, the caller can be authenticated accurately.

[Fourth Embodiment] Next, a fourth embodiment of the present invention will be described with reference to FIG.

FIG. 7 is a block diagram showing the configuration of each entity in the present embodiment. In FIG. 7, reference numeral 5 denotes a circuit for controlling communication, so that the communication device receives only communication from a specific entity. Is a circuit for setting. Other components 1 to 4 in FIG. 7 are similar to the components with the same reference numerals in FIG.

In the communication partner authentication method according to this embodiment, in each of the first, second and third embodiments, the ID of a certain specific entity is registered in advance, and communication from other entities is not received. The communication device is set in advance. Communication from unnecessary communication partners can be eliminated, and incoming control can be efficiently performed.

[Fifth Embodiment] Next, a fifth embodiment of the present invention will be described with reference to FIG.

FIG. 8 is a diagram showing a communication procedure according to the present embodiment for the callee authentication in which the sender authenticates the receiver and transmits the same when performing communication in the same environment as the first embodiment. . The configuration of each entity in this embodiment is shown in FIG.
Is the same as

(Procedure 1) As shown in FIG. 8, when entity A wants to communicate with entity B, entity A sends a request for communication to entity B.

(Procedure 2) When the entity B receives a communication request from the entity A, it creates message information M from its own ID, the ID of the entity A, and the random number generated by the random number generator.

(Procedure 3) Next, the entity B inputs the ID of the entity A into the memory unit 1 and selects the entity A from the set of the encryption keys secretly stored in the memory unit 1 and distributed from the center. Call the encryption key kAB. Next, the entity B uses the encryption key kAB to convert the information M by the calculation unit 2 according to the algorithm determined by the network to create the information kAB (M), and sends it back to the entity A.

(Procedure 4) Information kAB from entity B
Upon receiving (M), the entity A inputs the ID of the entity B into the memory unit 1, and selects the encryption key with the entity B from the encryption key set distributed from the center and secretly held in the memory unit 1. Call kAB. The encryption key k
The inverse transformation information k obtained by inversely transforming the information kAB (M) by the predetermined algorithm by the calculation unit 2 using AB
It is determined whether or not the IDs of the entity A and the entity B are obtained from AB ^-1 (kAB (M)), and when the IDs are obtained, the recipient of the communication request is authenticated as B.

By this method, even if the communication path is not secure, the callee can be authenticated accurately.

[Sixth Embodiment] Next, a sixth embodiment of the present invention will be described with reference to FIG. FIG. 9 is a diagram showing a communication procedure according to the present embodiment for the recipient authentication in which the sender authenticates and sends the recipient when performing communication in the same environment as in the first embodiment. The configuration of each entity in this embodiment is the same as that in FIG.

(Procedure 1) As shown in FIG. 9, when the entity A wants to communicate with the entity B, the entity A requests the entity B for communication, and at the same time, the entity A and the entity B The message information M created from the ID and the random number generated by the random number generator is transmitted to the entity B.

(Procedure 2) The entity B receiving the information M inputs the ID of the entity A into the memory unit 1,
The encryption key kAB for the entity A is called from the encryption key set distributed from the center and secretly held in the memory unit 1. Next, the entity B uses the encryption key k.
Using AB, the calculation unit 2 converts the information M according to the algorithm determined by the network to obtain the information kAB.
(M) is created and the information M is returned to the entity A.

(Procedure 3) The entity A, which has received the information kAB (M) returned from the entity B, inputs the ID of the entity B into the memory unit 1, and the memory unit 1 outputs the ID in the encryption key set. Call the encryption key kAB with the entity B from. Next, the entity A uses the encryption key k
The information kAB (M) is inversely converted by the operation unit 2 using AB, and the obtained inverse conversion information kAB ^-1 (kAB (M))
And the information M newly created by itself are compared by the comparator 4, and if the two are the same, the recipient of the communication request is authenticated as the entity B.

By this method, even if the communication path is not secure, the callee can be authenticated accurately.

[Seventh Embodiment] Next, a seventh embodiment of the present invention will be described with reference to FIG. FIG. 10 is a diagram showing a communication procedure according to the present embodiment for the recipient authentication in which the sender authenticates the recipient and transmits the recipient when performing communication in the same environment as the first embodiment.

The communication partner authentication method according to the present embodiment is different from the sixth embodiment only in the procedure 3, so that
The procedure 3'will be described.

(Procedure 3 ') The entity A which has received the information kAB (M) returned from the entity B inputs the ID of the entity B into the memory unit 1, and the memory unit 1
Then, the encryption key kAB for the entity B is called from the encryption key set. Next, the entity A uses the encryption key kAB to convert the information M converted by the calculation unit 2 according to the same algorithm as in step 2, and the information kAB (M) returned from the entity B to the comparator 4 If both are the same, the recipient of the communication request is authenticated as B.

By this method, even if the communication path is not secure, the callee can be authenticated accurately.

[Eighth Embodiment] In the encrypted communication device for carrying out the above-mentioned first, second, third, fifth, sixth and seventh embodiments, the random numbers constituting the message information M are information M has a role to make it different for each communication, but when the communication content is sent by encryption, the random number, or a combination of the random number and the encryption key distributed from the center by a predetermined algorithm is used. It may be used as a key. This makes it possible to change the encryption key for each communication.

[Ninth Embodiment] In the case of a network in which an incoming caller is called instead of calling an individual like the current telephone communication, the caller displays the ID of the individual recipient who wants to communicate with the incoming caller, By performing the callee authentication according to each of the fifth, sixth, and seventh embodiments described above, the callee-specified communication can be performed if the setting is made so that the specified person can communicate only when he / she arrives at the receiver.

[Tenth Embodiment] By combining the above-described fourth and ninth embodiments, incoming call control / destination designation communication is realized. This eliminates the need for both callers and callees to communicate with anyone other than the desired one, and
Even when one communication device is shared by several people like a telephone, communication between specified individuals becomes possible.

[Eleventh Embodiment] In the above-described fourth embodiment, if the communication contents are encrypted and sent, the contents can be known only to a designated entity, so that sender authentication / recipient designation communication is realized. It

[Twelfth Embodiment] In order to prevent an attack from a center, a plurality of centers are installed, and each of them independently distributes a unique encryption key set corresponding to the ID of that entity to each entity in advance. An entity keeps a set of multiple encryption keys secretly in a memory that can be accessed only by itself, and when an encryption key with a communication partner is needed, the encryption key distributed from each center It is also possible to select an encryption key for the ID of the communication partner for each set, synthesize them according to a predetermined algorithm to create a new encryption key, and apply the encryption key to each of the above embodiments.

[Thirteenth Embodiment] Next, FIG. 11 and FIG.
A thirteenth embodiment of the present invention will be described with reference to FIG. Figure 11
FIG. 3 is a diagram showing a configuration of a communication network in the present embodiment and a block diagram showing a configuration of each entity in the present embodiment.

When the number of entities in the communication network is large and the number of encryption key sets distributed by the center is too large to exceed the capacity of the memory section of each entity, the sender is set as follows.・ Recipient authentication is realized.

(Procedure a) The center is the ID of each entity
One-way function f that randomly converts one to one to a certain number
Publish.

(Procedure b) The center converts the ID of each entity using the one-way function f, and the converted number (f
(J); a key corresponding to each number (fi (j); i = 1, ..., m, j = A, B, ... N) obtained by dividing m of j = A, B, ..., N) The set of is distributed to each entity for the number of divisions m.

In FIG. 11, Si is a set of key sets distributed by the center for the i-th number of divisions (GA, GB,
..., corresponding to a collection of GNs).

The encryption key between the entities A and B in this case is obtained as follows.

(Procedure i) The entity A (B) performs conversion corresponding to the one-way function f on the ID of the entity B (A) as the communication partner, and divides the converted number into m.

(Procedure ii) Each of the numbers obtained by division is input to each memory unit 1 and secretly distributed from the center.
Call the corresponding encryption key from the set of encryption keys stored in.

(Procedure iii) These cryptographic instructions are calculated by the arithmetic unit 7
By combining according to the algorithm determined by, the encryption key between AB is obtained.

If the encryption key obtained by this method is applied to each of the above-mentioned embodiments, the capacity of the memory unit can be small even if the number of entities is large. Further, even if the number of entities is large, accurate caller / callee authentication is realized without communication for cipher meeting.

[Fourteenth Embodiment] In order to prevent an attack from the center, when the above-mentioned thirteenth embodiment is constituted by a plurality of centers, the procedure b of the thirteenth embodiment is changed to the procedure b'described below. change.

(Procedure b ') Each center converts the ID of each entity using the one-way function f, and the converted number (f (j); j = A, B, ..., N) is m. Number obtained by division (fi (j); i = 1, ..., M, j = A, B, ...,
A set of encryption keys corresponding to each N) is distributed to each entity for the number of divisions m.

If the encryption key obtained by this method is applied to each of the above-mentioned embodiments, the capacity of the memory unit can be small even if the number of entities is large. Even if the number of entities is large, accurate caller / callee authentication is realized without communication for cipher meeting.

[Fifteenth Embodiment] In order to prevent an attack from a center, when the above-mentioned thirteenth embodiment is constituted by a plurality of centers, another center is independently provided with the encryption key for each Si in FIG. May be distributed to each entity.

[Sixteenth Embodiment] The first to fifteenth embodiments described above.
In the embodiment of the present invention, a center is formed by defining an encryption key by the entity itself separately from the encryption key distributed from the center by being composed of a plurality of centers and having an entity in a part of the plurality of centers. The communication partner authentication method or the encrypted communication device shown in the first to fifteenth embodiments can be applied to a communication network that prevents attacks from the above.

[0072]

As described above in detail, according to the communication partner authentication method of claims 1 and 2 of the present invention, accurate caller / receiver authentication can be realized even when the communication path is not secure. it can. According to the encrypted communication device of claims 9 and 10 of the present invention, since the random number sent at the time of authentication or a combination of the random number and the encryption key by a predetermined algorithm is used as the encryption key, the same transmission / reception Even between persons, the encryption key can be changed for each communication.

[Brief description of drawings]

FIG. 1 is a diagram showing how ciphers are distributed in a communication system according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of an entity.

FIG. 3 is a diagram showing a communication procedure for performing caller authentication.

FIG. 4 is a diagram showing a communication procedure for performing caller authentication.

FIG. 5 is a block diagram showing a configuration of an entity.

FIG. 6 is a diagram showing a communication procedure for performing caller authentication.

FIG. 7 is a block diagram showing a configuration of an entity.

FIG. 8 is a diagram showing a communication procedure for performing callee authentication.

FIG. 9 is a diagram showing a communication procedure for performing callee authentication.

FIG. 10 is a diagram showing a communication procedure for performing recipient authentication.

FIG. 11 is a diagram showing a configuration of a communication network according to a thirteenth embodiment of the present invention.

FIG. 12 is a block diagram showing a configuration of an entity.

[Explanation of symbols]

GA, GB, ..., GN Encryption key set distributed to each entity from the center kAB, ..., kN-1N Encryption key 1 Memory unit 2, 6, 7 Operation unit 3 Circuit for requesting communication 4 Comparator 5 Communication Control circuit

Claims (10)

[Claims] 1. A center comprising at least one center and a plurality of entities, wherein the center distributes to each entity a pair of encryption keys corresponding to its identification information, and each entity distributes the pair of distributed encryption keys. In a communication partner authentication method in a network, which comprises a memory means for keeping secret and a computing means for executing a predetermined algorithm, communication between a first entity and a second entity among the plurality of entities One of the first and second entities is
The information generated from the identification information of both entities and a random number is used by the arithmetic means to generate the predetermined algorithm by using the encryption key of the other entity of the pair of the encryption keys held in the memory means of its own. Then, the conversion information is transmitted to the other entity, and the other entity uses the encryption key with the one entity of the encryption key set held in the memory means of the other entity. The conversion information is inversely converted by the calculation means, it is determined whether or not the identification information of each of the first and second entities is obtained from the inverse conversion information, and the communication partner is authenticated based on the determination result. Authentication method of communication partner. 2. An at least one center and a plurality of entities, wherein the center distributes to each entity a set of encryption keys corresponding to its identification information, and each entity distributes the distributed set of encryption keys. In a communication partner authentication method in a network, which comprises a memory means for keeping secret and a computing means for executing a predetermined algorithm, communication between a first entity and a second entity among the plurality of entities One of the first and second entities is
The information generated from the identification information of both entities and a random number is used by the arithmetic means to generate the predetermined algorithm by using the encryption key of the other entity of the pair of the encryption keys held in the memory means of its own. And sends the conversion information to the other entity, and the other entity encrypts the conversion information and the one entity of the pair of the encryption keys held in the memory means of its own. A communication partner authentication method, characterized in that the conversion information is converted by the arithmetic means using the key to compare the conversion information with a key, and the communication partner is authenticated based on the comparison result. 3. A center comprising at least one center and a plurality of entities, wherein the center distributes to each entity a set of encryption keys corresponding to its identification information, and each entity distributes the distributed set of encryption keys. In a communication partner authentication method in a network, which comprises a memory means for keeping secret and a computing means for executing a predetermined algorithm, communication between a first entity and a second entity among the plurality of entities One of the first and second entities is
Information is created from each identification information of both entities and a random number, and the created information is calculated by using the encryption key of the other entity of the encryption key set held in the memory means of its own. By the predetermined algorithm, the conversion information is transmitted to the other entity at the same time as the communication request is made, and the other entity transmits the encryption key of the encryption key held in its own memory means. The conversion information received from the one entity using the encryption key with the one entity of the set is inversely transformed by the arithmetic unit by the predetermined algorithm, and the first and second inverse transform information is used. The method for authenticating a communication partner is characterized by determining whether or not each piece of identification information of the entity is obtained, and authenticating the sender based on the determination result. 4. An at least one center and a plurality of entities, wherein said center distributes to each entity a set of encryption keys corresponding to its identification information, and each entity distributes said distributed set of encryption keys. In a communication partner authentication method in a network, which comprises a memory means for keeping secret and a computing means for executing a predetermined algorithm, communication between a first entity and a second entity among the plurality of entities One of the first and second entities is
Making a communication request to the other entity, the other entity creates information from the identification information and random numbers of both entities, and sends the created information to the one entity, The entity uses the cryptographic key with the other entity of the cryptographic key pair held in the memory means of the entity to receive the creation information received from the other entity, and the predetermined algorithm is calculated by the computing means. And returns the conversion information to the other entity, and the other entity uses the encryption key with the one entity of the pair of encryption keys held in the memory means of its own. The conversion information returned from the one entity is inversely converted by the arithmetic means by the predetermined algorithm, and the inverse conversion is performed. Communication partner authentication method characterized by determines whether the identification information of the first and second entities are obtained from a broadcast, to authenticate the caller by 該判 by results. 5. An at least one center and a plurality of entities, wherein the center distributes to each entity a set of encryption keys corresponding to its identification information, and each entity distributes the distributed set of encryption keys. In a communication partner authentication method in a network, which comprises a memory means for keeping secret and a computing means for executing a predetermined algorithm, communication between a first entity and a second entity among the plurality of entities One of the first and second entities is
Making a communication request to the other entity, the other entity creates information from the identification information and random number of both entities, and sends the created information to the one entity, and the one entity Is the predetermined algorithm by the arithmetic means using the encryption key of the creation information received from the other entity with the other entity of the pair of the encryption keys held in the memory means of its own. After conversion, the conversion information is returned to the other entity, and the other entity of the combination of the conversion information returned from the one entity and the encryption key held in its own memory means. The creation information is converted by the arithmetic unit using the encryption algorithm with the one of the entities. Comparing the objects, communication partner authentication method characterized by authenticating the caller by the comparison result. 6. An at least one center and a plurality of entities, wherein the center distributes to each entity a pair of encryption keys corresponding to its identification information, and each entity distributes the pair of distributed encryption keys. In a communication partner authentication method in a network, which comprises a memory means for keeping secret and a computing means for executing a predetermined algorithm, communication between a first entity and a second entity among the plurality of entities One of the first and second entities is
The communication request is made to the other entity, the other entity creates information from the identification information and random numbers of both entities, and the created information is stored in the memory means of the encryption key. Of the set of one of the entities and an encryption key is converted by the arithmetic means by the predetermined algorithm, and the conversion information is transmitted to the one of the entities, the one of the one of its own The conversion information received from the other entity using the encryption key with the other entity of the pair of encryption keys stored in the memory means is inversely transformed by the predetermined algorithm by the arithmetic unit, It is determined whether or not the identification information of each of the first and second entities can be obtained from the reverse conversion information, and the recipient is authenticated based on the determination result. Communication partner authentication method according to claim. 7. An at least one center and a plurality of entities, wherein the center distributes to each entity a set of encryption keys corresponding to its identification information, and each entity distributes the distributed set of encryption keys. In a communication partner authentication method in a network, which comprises a memory means for keeping secret and a computing means for executing a predetermined algorithm, communication between a first entity and a second entity among the plurality of entities One of the first and second entities is
Information is created from each identification information of both entities and a random number, and the created information is transmitted at the same time when a request for communication is made to the other entity, and the other entity is held in its own memory means. In addition, by using the encryption key with the one entity of the pair of encryption keys, the operation unit converts the creation information by the predetermined algorithm, and returns the conversion information to the one entity, One of the entities uses the arithmetic means to convert the conversion information returned from the other entity by using an encryption key with the other entity of the encryption key pair held in the memory means of the one entity. Inverse conversion is performed by a predetermined algorithm, and it is determined whether or not each piece of identification information of the first and second entities is obtained from the inverse conversion information. Communication partner authentication method characterized by authenticating the caller as a result. 8. An at least one center and a plurality of entities, wherein the center distributes to each entity a set of encryption keys corresponding to its identification information, and each entity distributes the distributed set of encryption keys. In a communication partner authentication method in a network, which comprises a memory means for keeping secretly and an arithmetic means for executing a predetermined algorithm, communication between a first entity and a second entity among the plurality of entities One of the first and second entities is
Information is created from each identification information of both entities and a random number, and the created information is sent to the other entity at the same time when a communication request is made, and the other entity sends the encryption code stored in its own memory means By converting the creation information received from the one entity with the predetermined algorithm by the computing means by using an encryption key with the one entity of the key set, the conversion information is converted into the one entity. The one entity uses the conversion information returned from the other entity and the encryption key of the other entity of the pair of encryption keys held in the memory means of its own. The created information is compared with that newly converted by the predetermined algorithm by the arithmetic means, and the called party is recognized based on the comparison result. Communication partner authentication method characterized by. 9. A cryptographic communication device using the communication partner authentication method according to claim 1, wherein a random number included in the creation information is used as the cryptographic key. apparatus. 10. A cryptographic communication device using the communication partner authentication method according to claim 1, wherein the random number included in the creation information and the cryptographic key are combined by a predetermined algorithm. A cryptographic communication device characterized by using a key as an encryption key.