Are there "light" versions of cryptographic hash functions?

Ryan B.

4/9/24, 12:43 PM

After tinkering with cryptographic hash functions, I started wondering if they do have counterpart functions that would imitate their cryptographic properties but with a lower level of strength in terms of their time/space complexity.

For instance, if I were to test certain collision algorithms in a simplified version of SHA1, which let's call SHA1-light, and it took X minutes to generate a collision, then I could estimate that it would take Y minutes in the standard SHA-1.

My interest lies in reproducing some of the well-known attacks, such as the Shambles attack on SHA-1, without necessarily having to spend $10k to verify if I have implemented the algorithm correctly.

108

0 + 3

sha-1

cryptanalysis

collision-resistance

Maarten Bodewes

4/9/24, 11:12 PM

Just a thought, but I guess for these kind of things the reduced rounds versions of any hash would be interesting to attack. I'm not *entirely* sure if it is any help w.r.t. the Shambles / chosen prefix attack though.

Ryan B.

4/10/24, 1:17 PM

@MaartenBodewes How to be _entirely_ sure then, any hint or pointer I can follow?

kodlu

4/10/24, 6:11 PM

My gut feeling: those attacks depend on hash function design structure and simple cutting down of bitwidth or reducing rounds is not likely to be easily tractable in terms of giving you some ratio in terms of collision (or other) attack time conversion

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: Are there "light" versions of cryptographic hash functions?

Post an answer

Most people don’t grasp that asking a lot of questions unlocks learning and improves interpersonal bonding. In Alison’s studies, for example, though people could accurately recall how many questions had been asked in their conversations, they didn’t intuit the link between questions and liking. Across four studies, in which participants were engaged in conversations themselves or read transcripts of others’ conversations, people tended not to realize that question asking would influence—or had influenced—the level of amity between the conversationalists.