I need to secure logs on a IoT device (Infineon TC233). It has 2 MB flash and a HSM. We are at the design stage of development.
Since logs will be primarily event & data logs, the size of the log file is likely to be in a few KBs. Additionally, logs will be dynamic files where event logs keep getting appended.
Logs on the device need to be sent to a server or other external units when requested for some diagnostics.
We need to protect the logs from tampering or deletion while they are stored on the device.
While encryption (symmetric key) is one mechanism, I am looking for better options, if any.