Patent · US Expired

Electronic document processing system and method of forming digital signature

US5465299A · kind A · utility

296Cited by
2References
18Claims
0Family size

Assignees

Inventors

Key dates

Filing dateNov 29, 1993
Grant dateNov 7, 1995
Priority date
Expiry dateNov 29, 2013

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04L2209/60
  • WIPO fieldDigital communication
  • WIPO sectorElectrical engineering

Abstract

In a terminal which received an electronic document with at leastone digital signature, when a user changes the contents of the received electronic document, a new digital signature is produced by enciphering signature data by using a secret key of the user, the signature data including a hash total of the document of a new version, personal information of the user (signatory), and version management information necessary to restore an electronic document of a former version from the electronic document of the new version. The new digital signature and the new version electronic document version are transmitted together with the received digital signature to a next person on a document circulating route.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.