Protection against manipulation of batteryless read/write transponders
US5430447A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 23, 1993 |
| Grant date | Jul 4, 1995 |
| Priority date | — |
| Expiry date | Aug 23, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K19/0723
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A hardware and software solution for providing a tamper-proof, batteryless, remote transponder which will only be programmable by an authorized user is disclosed. This goal is achieved through the use of a hardware Cyclic Redundancy Check (CRC) generator which checks during a WRITE function of the data that is received from the Reading/Writing (R/W) unit and also generates several protection bits (Block Check Character; BCC) which are sent back during the response function (READ). Before the CRC generator checks the data during a WRITE function, however, it must be set to a predetermined start value called a Segment Code, and the Segment Code of the R/W unit must be the same as the Segment Code of the transponder in order for a Write (or a READ) to be performed. Additionally, programming of the Selective Address must be done within a predetermined time window (has a predetermined Time Code). If either the Selective Address or the BCC generated by the CRC generator is incorrect, the transponder will be discharged such that it will not respond. In addition, if the R/W unit detects that the Selective Address is being programmed at a time other than the predetermined Time Code, the rea…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.