System for increasing the difficulty of password guessing attacks in a distributed authentication scheme employing authentication tokens
US5491752A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 2, 1994 |
| Grant date | Feb 13, 1996 |
| Priority date | — |
| Expiry date | Sep 2, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2221/2151
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An improved security system inhibits eavesdropping, dictionary attacks, and intrusion into stored password lists. In one implementation, the user provides a workstation with a "password", and a "token" obtained from a passive authentication token generator. The workstation calculates a "transmission code" by performing a first hashing algorithm upon the password and token. The workstation sends the transmission code to the server. Then, the server attempts to reproduce the transmission code by combining passwords from a stored list with tokens generated by a second identical passive authentication token generator just prior to receipt of the transmission code. If any password/token combination yields the transmission code, the workstation is provided with a message useful in communicating with a desired computing system; the message is encrypted with a session code calculated by applying a different hashing algorithm to the password and token. In another embodiment, the workstation transmits a user name to the authentication server. The server verifies the user name's validity, and uses an active authentication token generator to obtain a "response" to an arbitrarily selected chall…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.