JPH0430241A - Password control system - Google Patents

Abstract

PURPOSE:To facilitate the control of a cryptographic key by ciphering and transferring a password in a communication line and preventing the password and/or the cryptographic key from being preserved in a storage device on the side of a user. CONSTITUTION:The inputted password and time (transmission-side time) information of a clock 12 are ciphered in a ciphering means 13 by using the key generated in a key generation means 11 and they are transmitted as first data. First data which is received by using the key generated in a key generation means 14 is decoded in a decoding means 15. The decoded password and the password held in the storage device are compared in a comparison means 16, and the decoded transmission-side time information is judged to be accurate or not from present time information on the clock 17 by a time information judgement means 18. Furthermore, coincidence is detected in the comparison means 16 and the received password is judged to be just only when the time information judgement means 18 judges it to be accurate. Thus, the password is safely controlled and the control of cryptographic key is facilitated.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is a method of transmitting a password (also called a PIN number) input from one of two information processing devices connected through a communication path to the other information processing device. Transfer to information processing device,
The present invention relates to a password management method for verifying the validity of a password received by another information processing device.

Here, the information processing device is a device having a central processing unit (CPII), such as a microcomputer, a personal computer, an IC card, a terminal device, a communication processing device, an electronic exchange, a control device, or a computer system. be.

[Conventional technology]

Encryption is a method of concealing data. Cryptography methods include conventional cryptography and public key cryptography. Keys include an encryption key, which is an encryption key, and a decryption key, which is a decryption key.

Conventional cryptography refers to cryptography in which the encryption and decryption keys are the same, or one can be easily calculated from the other.

The DBS encryption algorithm (“Data Encryption 5tanda
rdll, FederaInformation P
rocessing 5standards Publ
cation46, tl, s, A, (1977
)), FEAL, No.-8M (authored by Miyaguchi et al., ``FEAL
-8 Cryptographic Algorithm” Research and Practical Application Report, Volume 37, No. 4
No. 75, pp. 321-327, NTT (1988)
)and so on. The public key encryption algorithm is R3A.
Cryptography (by R.E. Rivest et al.

A Method for Obtaining D
Digital Signature and Public
ic4ey CryptosystemsComn+t
+n1cations of the AC? 1
．． VoI! ,,21+~0.2.99°120-126
．． (1978)), the Rabin cipher (“M, Rab
inAuthor: Digitalized Signatur
es and Public4eyCryptosys
tews, MIT/LC5/TR-212, Tec
hnicalReport, Mon IT (1979))
and so on.

The encryption means is a conversion that encrypts arbitrary data A using a key Y and a cryptographic algorithm to output data B, and is expressed by the following equation.

B=E (Y, A) Here, the length of Y is the length of the encryption key. The decryption means is a conversion that decrypts data B using a key Z and an encryption algorithm to output data C, and is expressed by the following equation.

C=D (Z, B) Here, the length of Z is the length of the decryption key. The lengths of A and B may be arbitrary, for example, by using means such as a ciphertext chaining method and/or padding (length adjustment using known data).

When using a conventional cipher as an encryption algorithm, Y=
When z, it becomes A-C. When using public key cryptography as a cryptographic algorithm, A=C when Y and Z are a pair of public key and private key of public key cryptography.

A method in which one of two information processing devices connected via a communication path accesses the other, and the other device is made available for use by that user only when the other device authenticates the user's legitimacy. One of the methods for authenticating the user's authenticity is to use a password (or pin number) input by the user. Conventionally, the validity of passwords has been verified using the following method.

Method 1: The information processing device on the sending side transfers the password entered by the user as is, and the information processing device on the receiving side compares the received password with the password held for each user on the receiving side. Verify the validity.

Method 2: Each information processing device shares the encryption key in advance, and the sending information processing device encrypts and sends the password along with time information, and the receiving information processing device encrypts the password and sends it. Decrypt the data and verify the validity of password and time information.

[Problem to be solved by the invention]

A drawback of method 1 is that there is a risk that the password may be leaked through the communication channel.

The disadvantage of method 2 is that it is necessary to manage keys in addition to passwords.

Password management systems that have been used or proposed in the past have had problems with the security of passwords, or had the drawback that keys must be managed separately from passwords.

SUMMARY OF THE INVENTION An object of the present invention is to provide a password management method that safely manages passwords and facilitates the management of encryption keys for the security of passwords.

(Means for Solving the Problem) According to the invention of claim 1, the first information processing device uses a key created by a key creation means using a password input by a user to generate the password and sender time information. is encrypted to create first data, and the first data is transmitted to a second information processing device via a communication path, and the second information processing device receives the first data and uses the first data. The first data is decrypted using a key created by the same key creation means as the key creation means, using a password held in the second information processing device corresponding to the user, and the password and sender time information are decrypted. and the obtained password,
When comparing the passwords held by the second information processing device corresponding to the user and determining that the passwords are equal and that the sending side time information obtained by decrypting the first data is also correct; Only then, the second information processing device determines that the received password is the correct password.

According to the invention of claim 2, the key generation means is omitted in the invention of claim 1, and the password is used as a key in both the first information processing device and the second information processing device, and the other features are the same. It is.

[For production]

The authenticity of the user can be confirmed by the authenticity of the password. Here, the password is encrypted and transferred over the communication path, so it is safe. Furthermore, the first information processing device where the user directly inputs the password does not need to store the password and/or key in the storage device, so it is safe.

〔Example〕

FIG. 1 shows an example of an information processing system to which the present invention is applied. The first and second information processing devices 1 and 2 each have a CP
U3.4, storage devices 7 and 8 connected to these through signal lines 5.6, and first and second information processing devices 1 and 2;
are connected to each other by a communication path 9. FIG. 2 shows an example of the functional configuration of the password management system when the password management system of the present invention is applied to this information processing system. Each function in FIG. 2 is mainly accomplished by the CPU 34.

In the first information processing device 1, the input password PW1 is converted into a key by the key generation means 11. The key creation means 11 creates a function f(PW,) with the password PW as a variable, and r(PW,) is such that the password data has sufficient influence on the key and the key has no effect on the cryptographic algorithm. The conversion is performed so that it has a corresponding appropriate length, and in the following embodiments, a code is used as f(PW,). Using the key generated by the key generation means 11, the input password and the time (sending side time) information of the clock 12 are encrypted by the encryption means 13 and transmitted as first data. In the second information processing device 2, a key is created by the key creation means 14 from the password for the user stored in the storage device 8. The key generation means 14 has the same configuration as the key generation means 11. Using the key generated by the key generation means 14, the received first data is decrypted by the decryption means 15. The decrypted password and the password held in the storage device are compared by the comparing means 16, and the time information determining means 18 determines whether the decrypted sending side time information is correct based on the current time information of the clock 17. be done. The received password is determined to be valid only when the comparing means 16 detects a match and the time information determining means 18 determines that it is correct.

FIG. 3 shows an overview of the processing in the first information processing device 1.

Step 1: User A with user identifier ID uses the first information processing device 1
Enter password PW.

Step 2: The first information processing device 1 creates # from the password PW using the key creation means 11.

Kl=f(PW+)−E(PW++, PWlz), where pw,
=PWI−@PWI! , -1 indicates concatenation of two data.

When P W r + is less than the key length, one or more predetermined bit values (for example, O) are added to make it equal to the key length.

Step 3: The first information processing device 1 encrypts the password PW1 and the transmitting side time information TI from the clock 12 with the encryption means 13 using the key 1, and generates the first data M.

Create.

M I-E (K + , P w , HT ,
) Step 4: The first information processing device 1 receives the first data M and the user identifier I.
D, and are transmitted to the second information processing device 2.

FIG. 4 shows an overview of the processing in the second information processing device 2.

After step 4 of the first information processing device 1, the following processing is performed.

Step 5: The second information processing device 2 receives the user identifier ID and the first data M1 from the first information processing device l.

Step 6: The second information processing device 2 uses the key generation means 14 to add 2 to the key from the password PW held in the storage device 8 of the second information processing device 2 corresponding to the user identifier ID. create.

Ki = f(PWri-E (PW!1.PWzz), where PW,
=PW! ,, u P Wzz, P Wit is less than the key length, one or more predetermined bit values (for example, 0) are added to make it equal to the key length.

Step 7: The second information processing device 2 uses the key 2 to decrypt the decryption means 15.
The first data MI is decrypted by
and transmitting side time information T1 are obtained.

Mz = D (Kg1M+) -PW, IIT.

Step 8: The second information processing device 2 uses the password P obtained in step 7.
The comparison means 16 compares W and the password PWz held corresponding to the user A (identifier ID), and determines that they are equal and that the sending side time information T is correct by the means described below. PW is determined to be the correct password only when it can be determined that PW is the correct password. As a result, the first
It can be determined that the user with the user identifier ID who entered the password PW1 into the information processing device M1 is the correct user,
For example, information input manually from the first information processing device 1 is then accepted.

The time information determining means 18, which determines the validity of the transmitting side time information T, processes, for example, as follows.

Receiving side time information T2 when the second information processing device 2 receives the first data M1 is obtained from the clock 17, and Tt T+
If ≦H is satisfied, confirm that T is valid. H
may be a different value for each information processing device, and for the second information processing device 2, the length of the received message is determined by the transmission speed G of the L5 communication path 9, the inherent maximum delay time of the line (for example, switching processing, 1f magnetic wave propagation, etc.). (caused by) U, the predicted maximum deviation V between the clock 17 of the second information processing device 2 and the clock 12 of the first information processing device 1, and the margin W, it is determined by H=L/G+U+V+W.

If the length of the password is the same as the length of the key, the password may be used directly as the key. This is the invention of claim 2, and an example of its functional configuration is shown in FIG. 5 with the same reference numerals attached to parts corresponding to those in FIG. The processing device 1 uses the input password PW as a key to process the password PW.
1 and the sending side time information T are encrypted by the encryption means 13 to create first data M, which is combined with the identifier ID1.
is sent. The second information processing device 2 holds the password PW! corresponding to the received identifier ID! The first data M1 is decrypted by the decryption means 15 using the key.

Other details are the same as in FIGS. 2 to 4.

(Effects of the Invention) The password management method of the present invention described above has the following advantages over conventional password management methods. In the case of two information processing devices (for example, a terminal and a center), the data on the communication path is safe because it can be intercepted. Furthermore, the information processing apparatus to which the user directly inputs the password does not need to store a key, so it is safe.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a system comprising a first information processing device and a second information processing device to which the present invention is applied, and FIG. 2 shows an embodiment of the password management system according to the invention of claim 1. FIG. 3 is a flowchart showing the processing of the information processing device on the password sending side for multiple information processing devices, and FIG. 4 is a flowchart showing the processing of the information processing device on the password receiving side for multiple information processing devices. A flowchart showing an example, and FIG. 5 is a functional configuration block diagram showing an embodiment of the invention of claim 2.

Claims (2)

[Claims] (1) The first information processing device encrypts the password and the sender time information using the key created by the key creation means using the password input by the user, creates the first data, and The first data is transferred to the second data via the communication path.
The second information processing device receives the first data and generates the key by using the password corresponding to the user and held in the second information processing device. The first data is decrypted using a key created by the same key creation means as the above, and a password and sender time information are obtained. The second information processing device compares the correspondingly held passwords, and only if the passwords are equal and the sending side time information obtained by decoding the first data is also considered to be correct. , a password management method characterized by determining that a received password is a correct password. (2) The first information processing device creates first data by encrypting the password and sender time information using the password input by the user as a key, and transmits the first data to the second data via the communication path. The second information processing device receives the first data and locks it using the password held by the second information processing device corresponding to the user. decrypting the first data to obtain a password and sender time information, and comparing the obtained password with a password held in the second information processing device corresponding to the user;
The second information processing device determines that the received password is the correct password only when these passwords are equal and the sending side time information obtained by decoding the first data is also considered correct. password management method.