> try to imagine a scenario where there could be an operator== timing attack on a
password hashSure, that's simple. You're leaking information about the password hash to the attacker, which they can use to speed up an attack where they have large offline resources but are limited in their online guessing capacity.
Let's e.g. assume we have an unsalted hash, but the system limits us to one guess per second. The password is hashed, then compared with ==, taking some variable time we'll assume can be measured.
We use an iterated timing attack to discover a prefix of the password hash, then run an offline dictionary or brute force attack using that prefix. Passwords that match the known part of the hash are tried online, potentially revealing more of the hash as we go.
> It feels sometimes like people hear about the idea of timing attacks and then want to see them everywhere.
When it comes to side channel attacks, "vulnerable" is the default state.
Sure, that's simple. You're leaking information about the password hash to the attacker, which they can use to speed up an attack where they have large offline resources but are limited in their online guessing capacity.
Let's e.g. assume we have an unsalted hash, but the system limits us to one guess per second. The password is hashed, then compared with ==, taking some variable time we'll assume can be measured.
We use an iterated timing attack to discover a prefix of the password hash, then run an offline dictionary or brute force attack using that prefix. Passwords that match the known part of the hash are tried online, potentially revealing more of the hash as we go.
> It feels sometimes like people hear about the idea of timing attacks and then want to see them everywhere.
When it comes to side channel attacks, "vulnerable" is the default state.