Patent · US Expired

Public key data communications system under control of a portable security device

US5604801A · kind A · utility

283Cited by
8References
11Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 3, 1995
Grant dateFeb 18, 1997
Priority date
Expiry dateFeb 3, 2015

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04L9/0822
  • WIPO fieldDigital communication
  • WIPO sectorElectrical engineering

Abstract

A data communications system is described in which messages are processed using public key cryptography with a private key unique to one or more users (150) under the control of a portable security device (120), such as a smart card, held by each user, the system comprising: a server (130) for performing public key processing using the private key. The server (130) stores, or has access to, the private key for the, or each, user in encrypted form only. The private key is encrypted with a key encrypting key and each security device (120) comprises means for storing or generating the key encrypting key and providing the key encrypting key to the server (130). The server comprises secure means (360) to retrieve the encrypted private key for the user, decrypt the private key using the key encrypting key, perform the public key processing using the decrypted private key, and delete the decrypted private key after use.

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