3 ms·
The prekey is hashed into the symmetric key. Both the hash function and the symmetric cipher have avalanche effects that mean that N bit errors require the atta
by the8472 7y ago
The prekey is hashed into the symmetric key. Both the hash function and the symmetric cipher have avalanche effects that mean that N bit errors require the attacker to bruteforce 2^N combinations.
unprotected RSA keys on the other hand have structure and are dense in memory. That means fewer bit-errors and and the ability to guess the missing bits faster than O(2^N).
- mehrdadn 7y agoYeah but my concern was about direct leakage not brute force. That's what Spectre is about.
- the8472 7y agoOh yeah, but the temporal sparseness doesn't just apply to the symmetric memory encryption key. The most important part is that it also applies to the asymmetric host keys, which are the actual thing one wants to have protected. prekey -(hash)-> memory key -(decrypt)-> host private key
- repolfx 7y agoI think the assumption is the symmetric key can be stored in AES-NI registers that aren't susceptible to RAM based side channel attacks?