4 ms·

While you raise very good points overall, this one I have beef with: >SSDs that encrypt the drive with a key that doesn't depend on the password AFAIK, this i

by dexen 8y ago

While you raise very good points overall, this one I have beef with: >SSDs that encrypt the drive with a key that doesn't depend on the password AFAIK, this is the standard practice in software harddrive/filesystem encryption - LUKS, TrueCrypt, etc., for practical reasons, and with no negative impact on security if properly implemented. AFAIK again, this is also how Firefox handles encryption of stored website login/password credentials - they are always encrypted using locally generated & held key; in case user supplies her own password, this key is encrypted with that password, with no change to the actual login/password store. Contrast the following two scenarios: - derive encryption key from user-supplied password [potentially weak key] - encrypt the whole device / filesystem with the key [very long process, prone to interruption] - user wishes to change the password - re-encrypt the whole device / filesystem with the new key [very long process, prone to interruption] vs. - generate a cryptographically secure random or pseudorandom key - store the password in device - encrypt device with the key from the first write onward - when user sets password, encrypt the stored key [no change to content of device necessary] - from that point the user password is necessary to use the decryption/encryption key - when the user changes password, re-encrypt the stored key only [no change to content of device necessary] The second scenario is also more amenable to implementing various multi-password schemes, password-recovery techniques, and encryption secured with both passwords and hardware tokens.

amdavidson 8y ago
The difference is that the key was not encrypted with the password. If the key were properly encrypted (as you describe) the password check could not have been bypassed.
cantrevealname 8y ago
> You wrote: user supplies her own password, this key is encrypted with that password The critical point you're missing is that the Crucial SSD was not doing that step. If the key doesn't depend on the password, then the raw key has to exist somewhere on the Crucial hard drive or in its firmware, so the task becomes an easy hunt for the key with a debugger. No password cracking required.

by dexen 8y ago

amdavidson 8y ago

The difference is that the key was not encrypted with the password. If the key were properly encrypted (as you describe) the password check could not have been bypassed.

cantrevealname 8y ago

> You wrote: user supplies her own password, this key is encrypted with that password The critical point you're missing is that the Crucial SSD was not doing that step. If the key doesn't depend on the password, then the raw key has to exist somewhere on the Crucial hard drive or in its firmware, so the task becomes an easy hunt for the key with a debugger. No password cracking required.