CryptoNight is one of the fastest mining algorithms and part of the CryptoNote consensus protocol.

CryptoNight is a PoW mining algorithm for CPU and GPU mining, designed to be ASIC-resistant to prevent the centralization of mining power. It hopes to help users mine more efficiently using a combination of hashing functions, including the CryptoNight and the Keccak hash functions.

Its cryptographic hash function works around the Advanced Encryption Standard (AES), a military-level algorithm for extreme security, making CryptoNight a mining algorithm highly focused on security. Since Monero started using it as the hash algorithm for its blockchain consensus, CryptoNight’s reputation as a security algorithm has strengthened across the crypto world.

The CryptoNight algorithm’s creation is fascinating and recalls the origin of Bitcoin. Its creator — who goes by the fictitious name of Nicolas van Saberhagen — disappeared, just like the famous Satoshi Nakamoto.

Given the similarity, many believe that the two developers are the same person, with the mystery further enhanced by the spooky release date of CryptoNote, Dec. 12, 2012 (12/12/2012). CryptoNote was a security protocol and a privacy tool that promoted confidential transactions, non-linkable transactions and ring signatures.

https://cointelegraph.com/explained/what-is-the-cryptonight-mining-algorithm-and-how-does-it-work