Keyless entry system using a rolling code
US5600324A · kind A · utility
43Cited by
7References
4Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 29, 1996 |
| Grant date | Feb 4, 1997 |
| Priority date | — |
| Expiry date | Feb 29, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/84
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A keyless entry system which employs an identification code for each transmitter, a key sequence number, and a rolling code generated by a polynomial equation ensure unauthorized access. The system provides for resynchronization in the event of battery replacement or power failure. The system accommodates activation of a transmitter and incrementation of the rolling code when it is out of range of the receiver. This system further accommodates replacement of lost or stolen keys with a higher priority key, which then prevents access by the lost or stolen transmitter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.