X16R

Description:

X16R is a chained hashing proof-of-work (PoW) algorithm based on X11 that is used to secure the Ravencoin blockchain network. It is a combination of 16 different hashing algorithms that are used in a specific order, hence the name X16R (X for combination of, 16 for number of algorithms and R for the random order of the algorithms). The idea behind this algorithm is to make it more resistant to the use of specialized ASIC mining hardware.
The specific algorithms used in the X16R are:

• blake
• bmw
• groestl
• jh
• keccak
• skein
• luffa
• cubehash
• shavite
• simd
• echo
• hamsi
• fugue
• shabal
• whirlpool
• and an additional algorithm that is included to increase the memory requirements of the mining process.

The order of these algorithms is determined by the last 8 characters of the previous block's hash. As a result, each block mined on the Ravencoin network will have a different order of the 16 algorithms and will make it difficult for a specialized ASIC to be developed. X16R algorithm also uses a dynamic memory system to adjust the memory requirements for the mining process, this aims to prevent the centralization of mining power by making it difficult for any single miner or mining pool to gain a significant advantage.