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Expired European patentEurope

Secured message transfer system and method using updated session code

EP 0168667 B1 · Applicant: TANDEM COMPUTERS INCORPORATED

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Overview

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Listed from its EPO record in Patent Yard's archive of European patents past their term. Its claims, description and drawings are in the EPO PDF and on Google Patents, and the Claude kit works from them.

Why it's free to use

  • Filed June 20, 1985 and granted March 4, 1992. A European patent lasts at most 20 years from filing, so its term ended June 20, 2005.
  • A supplementary protection certificate, which can extend a medicine or crop-protection patent, adds at most five and a half years, so even that would have ended by December 20, 2010.
  • We check European rights only. A US or other national patent in its family could still be in force: check its family on Espacenet or Google Patents.
FiledJune 20, 1985
PublishedJanuary 22, 1986
GrantedMarch 4, 1992
Term endedJune 20, 2005
Application numberEP 85107626
Classification (CPC)H04L9/12 +2 more

Timeline

Timeline From EPO dates

1986198819901992199419961998200020022004Application filedJune 20, 1985PublishedJan 22, 1986Patent grantedMarch 4, 1992Term endedJune 20, 2005

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