Public key cryptographic apparatus and method
US4218582A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 6, 1977 |
| Grant date | Aug 19, 1980 |
| Priority date | — |
| Expiry date | Oct 6, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/08
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A cryptographic system transmits a computationally secure cryptogram that is generated from a publicly known transformation of the message sent by the transmitter; the cryptogram is again transformed by the authorized receiver using a secret reciprocal transformation to reproduce the message sent. The authorized receiver's transformation is known only by the authorized receiver and is used to generate the transmitter's transformation that is made publicly known. The publicly known transformation uses operations that are easily performed but extremely difficult to invert. It is infeasible for an unauthorized receiver to invert the publicly known transformation or duplicate the authorized receiver's secret transformation to obtain the message sent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.