Automatic resynchronization for remote keyless entry systems
US5862225A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 16, 1996 |
| Grant date | Jan 19, 1999 |
| Priority date | — |
| Expiry date | Dec 16, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07C2209/06
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
The present invention teaches a method and system for resynchronizing a remote keyless entry receiver having received a new encrypted message transmitted by the transmitter which does not match a previous encrypted message, also transmitted by the transmitter, and stored in memory. The method comprises a first step of transmitting and receiving a first new follow up encrypted message. Subsequently, the received new encrypted message is re-encrypted, and that result is tested against the received first new follow up encrypted message to determine whether there is a match. In the event both match, a second new follow up encrypted message transmitted and received. At this point, the received re-encrypted new encrypted message is re-encrypted a second time, and that result is tested against the received second new follow up encrypted message to determine whether there is a further match. If a match is made, the received second new follow up encrypted message is decrypted and the command within the received and decrypted second new follow up encrypted message is initiated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.