5 ms·
> If for example an application encrypts 2^48 messages under different 128-bit keys, and all messages start with the same few bytes, an attacker can build a loo
by barbegal 3y ago
> If for example an application encrypts 2^48 messages under different 128-bit keys, and all messages start with the same few bytes, an attacker can build a lookup table, try and lookup the ciphertext of 2^64 keys, and have a 2^-16 chance to decrypt one message. Not good.
This is satire right? The computational and storage requirements to preform such an attack to just get a small probability of decrypting one message seem ludicrous.
- mike_hock 3y agoMillions of terabyte disks of storage. Then repeat the attack a couple thousand times. In cryptography, you don't want "ludicrously" infeasible, as in the NSA can just about afford the hardware and do it, you want astronomically infeasible.
- SahAssar 3y agoAnd you want it to be so infeasible that even attacking a single message with perfect knowledge of all non-secrets is "astronomically infeasible". Its not enough to just make it astronomically infeasible to attack everyone.
- 2h 3y ago[flagged]