Nitrokey HSM different firmware versions

I have a couple of Nitrokey HSM. Some of them have firmware 2.6 and some have 3.1. What is the difference and is it possible to update firmware?

Best regards,

The older firmware corresponds to NK HSM 1, the newer to NK HSM 2. Also NK HSM 2 announces the smart card’s serial number as USB device’s serial number.

There is no upgrade path between the 2.x and 3.x version, because the secure element chip has changed from JCOP 2.4.2r3 to JCOP 3.

V2.6 is the last firmware available on the 2.x branch for JCOP 2.4.2r3 and 2.5 for JCOP 2.4.1r3 (serial <= DENK0100750). Firmware updates can be done via the PKI-as-a-Service Portal [1].


Thanks for information