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Cryptographic Hash Functions

links: AC1 TOC - Random Oracle & Applications - Modern Cryptography MOC - Index


MD5

SHA

Secure Hash Algorithms (SHA) refers to a set of cryptographic hash functions standardized by NIST.

SHA-1

SHA-2

  • applying the Davies-Meyer & Merkle-Damgård Transform construction
  • hash family with following hash functions: SHA-224, SHA-256, SHA-384, SHA-512, SHA-512/224, SHA-512/256
  • currently appear to be save and thus recommended when collision-resistant hashing is needed (output length 224 is not recommended anymore)
  • SHA-256 and SHA-512 are prone to length-extension attacks

SHA-3

  • SHA-3 Standard defines:
    • four fixed-length hash functions: SHA3-224, SHA3-256, SHA3-384, SHA3-512
    • two extendable Output Functions (XOFs): SHAKE128 and SHAKE256 (see SHAKE & cSHAKE)
  • applying the Keccak (Sponge) construction
  • also recommended

Security Strengths in Bits

security_of_sha_functions.png

BLAKE

BLAKE is a cryptographic hash function based on Bernsteins ChaCha stream cipher.

There are like in the SHA family several versions of the hash function:

  • BLAKE: submitted 2008, lost in final round of SHA-3 competition to Keccak
  • BLAKE2: hash function based on BLAKE (2012), BLAKE2b is faster than MD5, SHA-1, SHA-2 & SHA-3
  • BLAKE3: hash function based on BLAKE2 (2020), single algorithm with many desirable features (parallelism, XOF, KDF, PRF and MAC), faster than BLAKE2

  • Users of BLAKE2: Argon2, WireGuard, ...

Source en: Wikipedia


links: AC1 TOC - Random Oracle & Applications - Modern Cryptography MOC - Index