User authenticating system and method in wide area distributed environment

A user authenticating system of a computer system storing original information corresponding to a user of the computer system said user authenticating system comprising:

• certification authority means for issuing a certification to the user, the certification being determined by enciphering the original information including at least information identifying the user using a secret key;
• and
• a communicating system comprising:
• a first unit authenticating the user based on the certification, and
• a second unit transmitting the certification issued by said certification authority to said first unit, said communicating system operating in a mode selected from among one of three modes comprising:
• a first mode in which said second unit transmits the certification without modification, and said first unit obtains the original information by deciphering the certification and authenticates the user based on the original information;
• a second mode in which said second unit scrambles the certification and transmits data obtained by scrambling the certification to said first unit, and said first unit obtains the original information by descrambling and deciphering the data transmitted from the second unit and authenticates the user based on the original information;
• and
• a third mode in which said first unit transmits timing information to the second unit at random, said second unit scrambles the certification and transmits data obtained by scrambling the certification to said first unit each time the timing information is received, and said first unit obtains the original information each time the timing information is transmitted by descrambling and deciphering the data transmitted from the second unit and authenticates the user based on the original information.

A user authenticating method of a computer system storing original information corresponding to a user of the computer system, said method comprising the steps of:

• (a) issuing a certification from certification authority means to the user, the certification being determined by enciphering original information including at least information identifying the user using a secret key;
• (b) supplying the certification from the user to an authenticating unit;
• and
• (c) authenticating the user in said authenticating unit based on the certification, said step (c) including steps of:
• (c-1) obtaining the original information by deciphering the certification using a public key and producing a result based on the original information;
• (c-2) determining based on the original information obtained by said step (c-1) whether the user is authorized to use the computer system, the result obtained by said step (c-2) being used to authenticate the user.