Hash Function

Creator

Creator

Seonglae Cho

Created

Created

2020 Jun 21 6:31

Editor

Editor

Seonglae Cho

Edited

Edited

2025 Dec 15 10:33

Refs

Refs

A function that creates a small range domain

For security, MD5 or SHA-1 should not be used; for speed, BLAKE, MurmurHash, or xxHash are faster alternatives

Cryptographic Requirements

1. Pre-image resistance (One-wayness)

Given a hash it should be difficult to find

2. Second pre-image resistance (Weak collision resistance)

Given input it should be difficult to find

3. (Strong) Collision resistance

It should be difficult to find two messages such that having same hash

Hash Functions

notion image

notion image

Hash Function Notion

Merkle-Damgård construction

Speed test

rurban • Updated 2025 Dec 14 4:52

Hashes are a bit like fingerprints for data. A given hash uniquely represents a file, or any arbitrary collection of data. At least in theory. This is a 128-bit MD5 hash you're looking at above, so it can represent at most 2128 unique items, or 340 trillion trillion trillion. In

Speed Hashing

https://blog.codinghorror.com/speed-hashing/

Speed Hashing

암호화 MD5 vs SHA256

MD5는 메세지 축약 알고리즘으로써, 파일 무결성 검사용도로 많이 쓰이고 있다. 128bit 의 해쉬를 제공하며, 암호와와 복호화를 통하여 보안용도로도 많이 쓰인다. 하지만 암호화 결함이 발견되어 보안 용도로 사용할때에는 SHA와 같은 다른 알고리즘을 사용하는것이 권장되고 있다고 한다. SHA (Sechre Hash Standard) SHA(Secure Hash Algorithm, 안전한 해시 알고리즘) 함수들은 서로 관련된 암호학적 해시 함수들의 모음이다.

https://js2prince.tistory.com/entry/%EC%95%94%ED%98%B8%ED%99%94-MD5-vs-SHA256

암호화 MD5 vs SHA256

xxHash - Extremely fast hash algorithm

xxHash is an Extremely fast Hash algorithm, running at RAM speed limits. It successfully completes the SMHasher test suite which evaluates collision, dispersion and randomness qualities of hash functions. Code is highly portable, and hashes are identical on all platforms (little / big endian).

https://chromium.googlesource.com/external/github.com/Cyan4973/xxHash/+/375d401bd4a4eba07ee75d6e627546052cb5b0ec/README.md

Backlinks

Authentication System Hash Table Message Authentication Code

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