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### How can I calculate the probability of collisions of a hashing algorithm? [duplicate]

I'm pulling a “Dave” and I'm designing my own hashing algorithm. Not that I intend to use it, I'm not certifiable or anything, I just want the challenge of creating something. I'm not going to get ...
19k views

### Are hash functions strong against quantum cryptanalysis and/or independent enough of mathematics?

I work on ethereum and other blockchain technologies. And seeing that quantum pc's are someday going to see the light I have some questions / doubts. I was wondering if hash functions are strong ...
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### Calculation of the avalanche effect coefficient

Given a strict avalanche criterion matrix/dependence matrix for a hash function,how do I calculate the avalanche coefficient for it. I want to calculate a single parameter(value) which represents the ...
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### Just how surjective is a cryptographic hash like SHA-1?

From “Are common cryptographic hashes bijective when hashing a single block of the same size as the output” and “How is injective, inverse, surjective & oneway related to cryptography”, it is ...
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### Proof that MAC and hash composition is insecure

Let $F$ be a secure PRF and $H$ a universal hash function. How can I exhibit a pair $(F,H)$ whose composition $$S'((k_1, k_2), m) = F(k_2, H(k_1,m))$$ is an insecure MAC (or an insecure PRF, since a ...
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1 vote
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1 vote
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### Is exponentiation of a fixed generator modulo a prime collision-resistant?

Let $p$ be a prime number, and $g$ a generator of $\mathbb Z/p\mathbb Z$. For a message $m$, define the hash function $$h(m) = g^m \pmod p.$$ Is $h$ collision-resistant?
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250 views

### Is there an information theoretic equivalent of a trap door collision free function?

Warning: Possibly ill-posed question. I'm using the following definition from a recent paper available here. I believe their terminology is slightly different but reproduce my understanding of it ...
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Some standard compression procedures, like the IANA's gzip provided by HTTP protocol, will consume CPU-time anyway... So we can reuse compressed file, $Z(x)$, in the checksum procedure. That is, we ...