The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 20, 1993
Filed:
Mar. 09, 1990
David K Wittenberg, Hudson, MA (US);
Jerrold S Leichter, Stamford, CT (US);
Digital Equipment Corporation, Maynard, MA (US);
Abstract
Methods and apparatus for verifying the acceptability of a password proposed by a user of a secure system. The system stores a compressed version of a group of unacceptable passwords in a table of indicators. A mapper assigns indicators to passwords, such that more than one password may be mapped to a indicator. To initialize the system, an initializer applies the mapper to each unacceptable password of the group, and sets the indicators of the table that are assigned to each unacceptable password. Subsequently, a verifier applies the mapper to a proposed password and checks whether the indicator assigned to the proposed password is set. If the indicator is not set, it is determined without error that the proposed password is not in the group of unacceptable passwords, and may thus be assigned privileges in the secure system.