3 ms·

What is the closest crypto analog to this kind of key?

• jchook 7y ago
  Probably normal symmetrical key encryption with some kind of companion software. I think the physical key has the same blade shape on either side. The companion software would decrypt the ciphertext but prevent exporting the cleartext, forcing the user to first re-encrypt the text first.
• simias 7y ago
  Not really crypto but the only thing that comes to mind would be some RAII lock. You have to re-lock the resource as a side effect of leaving the function (dropping the lock). That's a bit far-fetched though.
• singron 7y ago
  I think it depends how you translate the locking analog. E.g. decrypting your key with {gpg,ssh}-agent keeps the plaintext key in memory in the agent. If the machine reboots or a timeout elapses, the memory is cleared and the key has to be unlocked again.
  • alister 7y ago
    On-the-fly encryption, Truecrypt as the canonical example, has this property too. The key is always in memory, decrypting text on the fly, but a reboot or period of inactivity will wipe the key.