JPH01101042A - Authentication device - Google Patents

Abstract

PURPOSE:To prevent a dishonest resending by a third party by preparing integers dependent of a time and an authenticator and providing a deciding means to decide whether the identification information of a sending side is made or not. CONSTITUTION:To each user, a card, onto which integers (n), alpha, e1 and Si of the degree of 512 bits are written, is distributed from a card publisher or a center. Only the Si is the secret integer different for each user, and the others are common to each user. In forming an authenticator, a random number (r) is generated, and x=alpha<er>(mod n) is calculated from (e), alpha and (n) read out of the card of the user. Next, the hash function value of data Data to be transmit ted, a time Time and an above-mentioned integer (x), C=hash(Time, x, Data) is calculated. Next, whether a sent authenticator (x, y) and Y<e>/x<c1>(mod n) such as the (e), (n) and (x) from the card of the receiving side user are equal to an ID information ID1 of the transmitting side user or not is decided.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to the authentication of communicating users or messages as well as the abbreviation of communications in networks.

(Prior art) Nee Shamir (A, Shamir) uses Crypto84 as an authentication method.
(The method proposed in Crypto'[+4> is highly evaluated as a practical method that uses ID information such as each user's name.

(Problem to be solved by the invention) Shamir's method has two drawbacks:

One is that if a third party records a message sent from a legitimate user to another legitimate user and later plays and transmits it, the receiver cannot detect the fraud. Furthermore, if you try to combine it with encrypted communication, you will need a new information band to send the key.

(Means for solving the problem) According to the present invention, in an authentication device that creates an authentication code,
Random number generation means for generating a random integer r, storage means for storing four predetermined integers n, α, e, and s, and an integer C that depends on at least time and the random number.
and hashing means for generating the integers n, α, e,
Two integers a'' (sod n) and S from s, c, r
An authentication device is obtained, comprising: an authentication code generating means for generating an authentication code consisting of a ” (sod n).

Further, according to the present invention, two integers a are created from four predetermined integers n, α, e, and s, a randomly selected integer r, and an integer C that depends on at least time.
(sod n) and S a '' (sod n) from the sender, and an authentication device that performs authentication generates an integer C1 that depends on at least the time and the authenticator. means and said integers n and e
a storage means for storing the integers n, e, x, y, c1;
According to the present invention, there is obtained an authentication device which is characterized in that it comprises a determination means for determining whether or not ye/x” (sod n) is the identification information of the sender.

Further, according to the present invention, in an authentication device that creates an authentication code to be sent to a communication partner and generates a key, a random number generation means that generates a random integer r, and a predetermined
storage means for storing integers n, α, e, s; hashing means for generating an integer C depending on at least time and the random number; , two integers a ”(sod n) and S・a′″″(ma
d n) authenticator generation means for generating an authenticator consisting of;
If the authentication code sent from the communication partner is correct, an authentication device is obtained which is characterized by comprising a key means for generating a key using the authentication code and the integer r.

(Operation) FIG. 1 is a very rough flowchart showing the operation and principle of the present invention. Hereinafter, the side that creates the authenticator will be referred to as the proving side, and the side that verifies the authenticator will be referred to as the authenticating side. The proving side creates an authenticator that can be verified by the authenticating side and sends it along with other necessary data. This is shown in FIG. 1(a). On the other hand, the authentication side determines whether the sent authentication code is correct or not. This is the first
It is figure (b). Furthermore, on the receiving side, an encryption key can be secretly created using the authenticator, as shown in FIG. 1(c). The other side of the encrypted communication must also have the same abbreviation key, but this is because the receiving side acts as the proving side in (a) and sends the authenticator to the sending side, and the sending side acts as the authenticating side and sends the authenticator (c). ).

(Embodiment) FIG. 2 is a configuration diagram showing an embodiment of the present invention. It is assumed that one of the terminals connected via the network is used by a sending user, and another one is used by a receiving user. A card reader is installed in each terminal, and software or hardware for authentication is installed in the terminal to execute the process shown in FIG. Each user has an integer of about 512 bits n, α, e.
3. Cards with Si written on them are distributed by the card issuer (or center). Here, only Sl is a secret integer that differs for each user, and the others are common to each user. user i
If the ID information of is IDI, then Si is St” (mod n)=ID.

It is made to satisfy. What you can do in this way is the Communication of the NCM (Co.
communication of the ACM) 2nd
It is shown in Vol. 1, No. 2, pp. 120-126.

The operations to be performed by the terminal are shown in FIG. 1, and examples of authentication code creation, authentication code verification, and key generation are shown in Section 3.
Shown in Figure 4.5.

When creating an authenticator, a random number r is generated and x = a'' (sod n
, ). Data to be sent one after another, time, and hash function value of the integer X, C=h a
Calculate s h (Time, x, Data). Here, the hash function hash is, for example, Ieeeeee (I
EEE) Confirmation Computer (COMPUTER) Magazine 1
This is a function described in 983/2 same issue, pages 55 to 62. Data includes the sender's I in addition to the so-called message.
D information and other data may also be included. At this time, the authenticator (x, y) is given by the above X and y=Si-d'' (mod n).Si is also an integer read from the user's card.

In the authenticator verification in Figure 4, c = h a sh (Time, x, Data) using the hash function.
Calculate. Here, Data is the data sent from the sending side, Time is the time information used by the sending side when creating the authentication code, and if the receiving side does not know it correctly, T
I need you to send me an ime. X is part of the authenticator sent. Next, determine whether the authenticator (x, y) sent and e, n, x, y''/x' (mod n) from the receiving user's card are equal to the sending user's ID information ID If they are not equal, it is considered invalid data. If we use (x, y) sent by the sending user, from the definition of x, y, y@/x' = Si"a" modulo n. e/aer” = ID + roar.

In the key generation shown in FIG. 5, a random number R is used and WK=XR(m
od n). Here, X is the one sent from the authentication side, and the random number R is the random number used to create the authentication code. That is,
On the receiving side, when generating a key, an authenticator is created as described in the (effect) section, and this is the random number R used at that time. The transmitting side also uses the random number r used for creating the authentication code for key generation. On either side WK will be equal to α''R(locjn).

In the above embodiment, the middle power remainder division z=ab(sodn)
The calculation can be done by the terminal's software or by the processor. Also, time information T is fine.

(Effects of the Invention) As explained above in detail, the present invention enables authentication with functions such as preventing unauthorized retransmission by a third party and generating encryption keys, which is useful for network communication, etc. Useful.

[Brief explanation of the drawing]

Figure 1 is a flowchart showing the operation and principle of the present invention, Figure 2 is a configuration diagram showing an embodiment of the present invention, and Figures 3.4.5 are authentication code creation, authentication code verification, and key generation in Figure 1. It is a figure which shows each Example. In the figure, 101 indicates an authentication code generation function, 102 indicates an authentication code transmission function, 111.121 indicates an authentication code reception state, 112.122 indicates an authentication code verification function, and 123 indicates a key generation function.

Claims (1)

[Claims] 1. An authentication device that creates an authentication code, comprising a random number generation means for generating a random integer r, a storage means for storing a plurality of predetermined integers, and at least a time and the random number. An authentication device comprising: hashing means for generating a dependent integer c; and authentication code generation means for generating an authentication code from the plurality of integers, c and r. 2. An authentication device that receives from a sender an authentication code created from a plurality of predetermined integers, a randomly selected integer r, at least a time, and an integer c that depends on the random number, and performs authentication, at least the time and the authentication code. a hashing means for generating an integer c_1 depending on the child; a storage means for storing a plurality of predetermined integers; and a predetermined conversion from the integer, the authenticator, and c_1, and the result is the identification of the sender. An authentication device comprising: determination means for determining whether or not information is obtained. 3. In an authentication device that creates an authentication code to be sent to a communication partner and creates a key, it includes a random number means for generating a random integer r, a storage means for storing a plurality of predetermined integers, and at least a time and the above. random number and integer c depending on
hashing means for generating the plurality of integers and c, r.
An authentication device comprising: an authentication code generation means for generating an authentication code from a communication partner; and a key generation means for generating a key using the authentication code sent from a communicating party and the r when the authentication code is correct.