X16R is a hashing algorithm specifically associated with the mining algorithm used by certain cryptocurrencies, most notably Ravencoin (RVN). ^[1]

Overview

X16R stands for "X16 Random," designed to be a proof-of-work (PoW) algorithm. Unlike traditional PoW algorithms that use a fixed set of hashing algorithms, X16R employs a chain of sixteen different hashing algorithms, which are dynamically selected based on the last block's hash. ^[1][2]

The 16 algorithms that makeup X16R are as follows: Blake, BMW, Groestl, JH, Keccak, Skein, Luffa, Cubehash, Shavite, Simd, Echo, Hamsi, Fugue, Shabal, Whirlpool and SHA512.

This X16R algorithm works in such a way that it constantly disrupts the algorithm's chaining order. The order of the 16 different hashing algorithms will dynamically change based on the hash value of the previous block. Due to the dynamic change of the algorithm order building an ASIC for X16R is difficult. ^[2]

Ravencoin is a cryptocurrency that utilizes the X16R algorithm. RVN was created to enable the efficient creation and transfer of assets on a blockchain. It has gained attention for its focus on asset issuance and transfer capabilities. ^[2]

History

The history of hashing for cryptocurrencies began with SHA256 for Bitcoin, Scrypt for Litecoin, Ethash for Ethereum, X11 for Dash, and X13, X15, and X17. X16R is the next step in this evolution to find a better mining algorithm. Algorithm changes in cryptocurrencies aim to minimize the impact of specialized hardware on the mining landscape. ^[1]

Originally, Bitcoin mining was meant for widespread computer use. As Bitcoin's value rose, mining shifted to Graphics Processing Units (GPUs) for parallel processing. Economic incentives led to the use of Field-programmable Gate Arrays (FPGAs) and, ultimately, purpose-built Application-Specific Integrated Circuits (ASICs). ASICs outperformed other technologies, making alternative mining methods impractical. The latest evolution in Bitcoin mining involves faster and more energy-efficient ASIC hardware, marking a likely final stage in its development. ^[1]

To minimize the impact of ASIC miners, cryptocurrencies developed memory-intensive hashing algorithms, and the X16R algorithm was introduced by Ravencoin to block ASICs. However, no PoW algorithms (even X16R) can block ASICs permanently. As the economic value of mining increases and as more coins adopt a single algorithm the development of ASICs will get accelerated. Ravencoin developers are committed to changing the algorithms used in x16r if they ever find an ASIC being developed. ^[1][2]

X16R Coins

Ravencoin was the first coin to use the X16R hashing algorithm. This algorithm is now used by many other coins due to its ASIC resistance. Currently, this algorithm is used by several PoW coins. Some are just a clone of Ravencoin, some are masternode coins, some are inactive and on some coins, the PoW phase has already ended. ^[2]

Other coins that fall under this algorithm include GPUnion (GUT), Stone Coin (STONE), Help The Homeless Coin (HTH), CrowdCoin (CRC), Gravium (GRV), Motion (XMN), Hilux (HLX), etc. ^[2]