2
$\begingroup$

2015's Argon2 publication suggests that cryptocurrency hashing like password hashing on backend servers should not be subject to side-channel attack:

Argon2d is optimized for settings where the adversary does not get regular access to system memory or CPU, i.e. he can not run side-channel attacks based on the timing information, nor can he recover the password much faster using garbage collection [17]. These settings are more typical for backend servers and cryptocurrency minings.

Why ?

$\endgroup$
1
  • $\begingroup$ It is not a far-fetch scenario that when a value which hash has the desired property is found, the miner pool briefly stops while moving to the next block, creating a voltage surge on the power feed, detectable at a large distance by SPA. Time elapsed since start of mining the block could be revealing of the number that (conventionally) has a value. If there's no mechanism against that, it could allow an attacker to find that number effortlessly. There are various ways to counter that, including randomizing the starting point of mining in a block. This attack is unrelated to the hash itself. $\endgroup$ – fgrieu Oct 20 '20 at 19:16
2
$\begingroup$

It is generally assumed that cryptocurrency mining is an "offline" process, that is you take one input from outside, and then after a long while you report back with a result. In particular, it is assumed that an adversary does not see when exactly one search starts and when it ends nor do they see how many tries it took you exactly. This makes timing-based side-channels extremely hard - most likely impossible - to execute, even if you leak "a lot" in terms of traditional timing side channels. Furthermore the input to the hash function - which is what you'd want to recover - is only secret right up until you make your outside communication announcing said input - at which point a more sophisticated recovery of it would be pointless...

$\endgroup$
1
  • $\begingroup$ and one ever doesn't know to select Argon2i or Argon2d the can use Argondi $\endgroup$ – kelalaka Oct 20 '20 at 15:13

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.