05168520 is referenced by 337 patents and cites 36 patents.

A method and apparatus for providing improved security for a personal identification number (PIN) in a personal identification and verification system of the type wherein a time dependent nonpredictable code is generated at a device in the possession of the individual, which code is unique to the individual and this code is communicated to, and compared with a nonpredictable code generated at a central verification computer. In this system, the PIN is mixed with the nonpredictable code before transmission of these values to the central verification computer. A nonsecret code is previously transmitted to the central verification computer and is used to retrieve the PIN and the appropriate nonpredictable code for the user. These values are used to strip the PIN from the transmitted nonpredictable code and the stripped PIN and remaining nonpredictable code are compared with the corresponding retrieved values in order to determine verification.

Title
Method and apparatus for personal identification
Application Number
676626
Publication Number
5168520
Application Date
March 18, 1991
Publication Date
December 1, 1992
Inventor
Kenneth P Weiss
Newton
MA, US
Agent
Wolf Greenfield & Sacks
Assignee
Security Dynamics Technologies
MA, US
IPC
H04L 9/32
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