[lisper]

The SC4-HSM is not designed to be secure against physical compromise, but it can be made resistant against such attacks by encrypting the keys with a pass-phrase. This is not a perfect solution because the pass-phrase needs to be entered through a non-secure host, but it's better than nothing. An attacker would need to compromise the pass phrase and obtain physical possession in order to mount a successful attack.

[dfox]

With this security model it is in essence no better than plain USB flash drive. I would assume that adding at least some protection against physical attacks could be reasonably simple and would greatly expand the usefulness of the device (eg. making it somehow inherently tamper-evident and replacing the DFU bootloader with something custom and open that does the same thing as RDP Level 1, but without the bricking risk)

[lisper]

> With this security model it is in essence no better than plain USB flash drive

I disagree. With the right firmware, the SC4-HSM can securely generate keys that cannot be compromised without decapping the chip.

[btchip]

the projects I quoted above have the same "security model" then