Questions tagged [collision-resistance]

Difficulty of finding two different inputs that hash to the same value

724 questions
Filter by
Sorted by
Tagged with
30 views

Is it possible for a given plaintext and ciphertext to have two different keys? [duplicate]

This has probably been asked before but for a given ciphertext and plaintext pair, is it possible to have two different keys producing said pair? Or there are no collisions in AES, unlike hashing ...
226 views

Can a collision resistant hash return zero?

Recently, I have been reading the original proof of GCM. It mentioned the properties of "almost universal" and "return zero" for hash function. I wonder if there is a connection ...
76 views

What is the fastest 128-bit non-cryptographic hash function?

I need a 128-bit hash function which is extremely fast since it will be used for generating unique IDs for billions of objects. It doesn't need to be a cryptographic hash function nor does it have to ...
1k views

96 views

1 vote
68 views

Is it possible to get the negative point with −x in that version of the Pedersen hash over the BaybyJubJub curve?

The Pedersen hash is a low constraints friendly hash for Zk-Snarks. Unlike many algorithms, the Pedersen hash returns a point P = (x,y) on a curve as a hash. ...
1 vote
44 views

1 vote
76 views

Hash Flooding a Randomized Modular Hash Table

Assume we have a hash table using the function h(x) = x mod 32. h(x) = x mod 33. Also assume it dynamically resizes by doubling the amount of buckets and rehashing. If I was able to provide inputs for ...
381 views

Checking encoded strings for a hash collision in Python [closed]

There is a common term used in cryptography called a hash collision. If I am reading the definition correctly on Wikipedia, this can occur if two different data values give rise to the same hash ...
1 vote
68 views

How to estimate the collision resistance of a hash function if a secondary key is used (keyed hash function)?

According to the documentation of HighwayHash, for finding a collision are expected $m \over 2$ guesses, being $m$ the message. By contrast, 'strong' hashes such as SipHash or HighwayHash require ...
1 vote
169 views

Does an increase of message size increase the number of guesses to find a collision?

If I hash a 256-bit message and generate an output digest of the same size with a cryptographic hash function then the number of guesses to find a collision is expected to be 2^128. Does increasing ...
217 views

Confusion+Diffusion comparison table? (e.g. with Avalanche Criterion / SAC)

I'm looking for a general comparison of encryption algorithms in regard to Confusion and Diffusion (as defined by Claude Shannon), and if possible, specifically for their SAC and BIC quality. For ...
1 vote
43 views

Is a single 256 bits hash table in which the digests are from mixed cryptographic hashing algorithms still considered collision resistant?

Consider a single hash table containing digests from about 10 different 256 bits cryptographic hashing functions, like SHA256, SHA3, KECCACK256, BLAKE2, BLAKE3, etc... Is such table still considered ...
1 vote
87 views

What is the proof that the RSA is collision-free?

We have the RSA function: $c = m^e (mod n)$. I would like to know the proof that there is not an $m_1$ and an $m_2$ message that produce the same $c$. My thoughts: We know that $m \le n$, so \$m_1 \...
2k views

Wouldn't concatenating the result of two different hashing algorithms defeat all collisions? [duplicate]

Let's say I have three messages: A B C And I run each of these through two different ...
117 views

Is there a CRHF based on integer factorization problem or RSA assumption

We know that in the black-box sense, we cannot use one-way functions to construct Collision Resistant Hash Functions.I feel that in my impression, I have never seen CRHF based on integer factorization ...
182 views

UOWHF vs CRHF / Relevance of UOWHF

What's the difference between UOWHF and CRHF and why are UOWHF useful? As far as I understand, Universal One-Way Hash Functions are an alternative to CRHF. While for CRHF it is hard, given randomly ...