Patent ID: 7178041

Claim:
A system for implementing a trusted counter in a personal communication device, comprising: a secure module in a personal communication device comprising a first read-only, tamper resistant storage device, said personal communication device containing no writable storage; a second read-write, tamper resistant storage device in an electronic card removable from the personal communication device; a third read-write, insecure storage device in the removable electronic card; and a processor in communication with the secure module, the second and the third storage devices configured to: execute authentication of the second storage device by the secure module; issue a create counter request by the secure module to the second storage device; send a unique ID identifying a current counter value from the second storage device to the secure module; compute an encrypted envelope of the unique ID with the secured module by applying a cryptographic transform to the unique ID; and write a state value and the encrypted envelope of the unique ID to the third storage device.