Low cost encryption transponder
US5970148A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 2, 1997 |
| Grant date | Oct 19, 1999 |
| Priority date | — |
| Expiry date | May 2, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/046
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Novel means of achieving increased security while still obtaining a low cost, manufacturable device are disclosed and claimed. The first mode of operation is the learn mode which provides means for initial checkout with no security. In the learn mode of operation, the interrogator and transponder may be switched to a predetermined error detection algorithm, i.e. CCITT(Start Mask, CCITT Mask), and certain information is programmed into the transponder memory. During programming, all the bits received from the interrogator are shifted through the preintialized CRC generator. In addition, once the transponder response is sent back to the interrogator, the response is also shifted through a preinitialized CRC generator within the interrogator(which could be a software implementation). Because neither the Cypher Key nor the Function Key are directly readable once programmed, an encryption must be performed to verify the proper Cypher Key and Function Key were programmed into the transponder's memory. In the second and encryption mode of operation, after a special Command/Address is transmitted, a Random Number (which may vary in length but which has a minimum length) is transmitted from…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.