Apparatus and method for effecting a key change via a cryptographically protected link
US4688250A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 29, 1986 |
| Grant date | Aug 18, 1987 |
| Priority date | — |
| Expiry date | Jan 29, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L9/32
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Messages sent from an earth station to a satellite by a command link are authenticated within the satellite before being executed. Authentication is accomplished by comparing a codeword appended to the message to a codeword generated within the satellite. This codeword is a cryptographic function of the message data and a secret operating key. A key change command from the earth station causes the satellite authenticator to generate a new operating key based a secret master key, a supplemental private code, and a publicly available initialization vector. The codeword appended to the key change command is encrypted in the new key and, if it agrees with a codeword generated by the satellite authenticator, the new key becomes the operating key and the key change function is complete.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.