4 ms·

The read-only copy could be different from the running copy.

• rcthompson 10y ago
  If you trust the hardware enough to use it for 2-factor authentication, then I think you trust it enough to be honest with you about its contents.
  • dfox 10y ago
    The problem there is that in usual case, the read-only access to software will not be provided directly by the hardware, but by the same software you are trying to verify. In theory, this could be solved by verifying whole memory of the device, but that still depend on you believing that the device does not have more memory than what it should have.
    • leni536 10y ago
      > the read-only access to software will not be provided directly by the hardware, but by the same software you are trying to verify. Why not?
      • dfox 10y ago
        Because in the usual case you want to do such verification through same interface as normal operation, both for usability reasons and to limit number of interfaces that cross the security boundary.
• makomk 10y ago
  The usual trick is to ensure that the firmware + user data fills all available storage space on the hardware so there's no room for other code, then add time limits and complexity to the verification code so they can't do any tricks with stuff like compression.