5.7.16. SE05X Timestamp

The timestamp is a 12-byte value. The most significant 4 bytes are persistent and the least significant 8 bytes are transient. The persistent value is incremented at every session open and the transient 8 bytes are incremented every 100ms and reset at every session open.

So every time the timestamp is read, the newer value will always be greater than the previous value.

This example demonstrates that the timestamp value is incremented internally. Timestamp is used by the applet during attestation. We initially read the timestamp value and then perform attestation operation. We compare the initial timestamp with the timestamp received during attestation. The newer value must be greater than the older value.

5.7.16.1. Building

Build the project with the following configuration.

  • Applet=SE05X_C

  • Project = se05x_TimeStamp

5.7.16.2. Running

On successful execution, you would be able to see the timestamp printed out:

App   :INFO :timestamp.ts (Len=12)
      00 00 00 08    00 00 00 00    00 1F BD 00
App   :INFO :new_timestamp.ts (Len=12)
      00 00 00 08    00 00 00 00    00 20 B7 00
App   :INFO :ex_sss Finished

As you can see in the above logs, the timestamp value received during attestation operation is larger than the previous value.