What is skeen?

Skeen is a cryptographic hash function that was designed for speed and security. It was a finalist in the NIST hash function competition, though Keccak (SHA-3) was ultimately selected.

Key features of Skeen include:

  • Based on Threefish: Skeen uses the Threefish tweakable block cipher as its core transformation.

  • Unique Permutation: The use of Threefish allows Skeen to have a relatively simple and fast permutation.

  • Tweakey Framework: Skeen utilizes a unique 'tweakey' framework where the key, tweak, and message are all processed in a similar manner. This is a central aspect to its security claims.

  • Arbitrary Output Size: Skeen can produce hash outputs of arbitrary bit lengths.

  • Configurable: Skeen provides some level of configurability which can be used to adjust the algorithm for different security/performance trade-offs.

  • Security Claims: Skeen's designers provided detailed security analysis and claimed strong resistance to various cryptographic attacks. However, like all cryptographic algorithms, continued research and cryptanalysis are essential to verifying its long-term security.