Hello everyone, my name is Cuihua, the editor of POWPOWER, POWPOWER has been focusing on the mining area for 4 years, is the official distributor of IPollo, and has established long-term partnerships with Bitmain, Avalon, Jas miner, inno, Whatsminer and Goldshell. When learning about mining and mining machines, you can often see a word SHA-256, so what is it? Today we will learn about SHA-256 together!

SHA-256 is the encryption algorithm used by some BTC digital currencies. However, it uses a lot of computing power and processing time, forcing miners to form mining pools for the benefit.

When it comes to SHA-256, we must not mention the SHA family. SHA (Secure Hash Algorithm, translated as Secure Hash Algorithm) is a series of ciphers designed by the National Security Agency (NSA) and released by the National Institute of Standards and Technology (NIST). hash function. The SHA security encryption standard is one of the most widely used and secure compression algorithms in the world. With the continuous deepening of cryptography research and the rapid development of computer technology, the SHA-256 algorithm has been fully promoted and applied.

The length of the hash value used by the SHA256 algorithm is 256 bits. This is an abstract class. The only implementation of this class is SHA256Managed. The SHA256 compression function mainly operates on a 512-bit message block and a 256-bit intermediate hash value. In essence, it is a 256-bit encryption algorithm that encrypts the intermediate hash value by using the message block as a key.

For messages of any length, SHA256 produces a 256-bit hash value called a message digest. This digest is equivalent to an array of length 32 bytes, usually represented by a hexadecimal string of length 64, where 1 byte = 8 bits, and the length of a hexadecimal character is 4 bit.

SHA256 is used in several places in BTC. First, the public key is converted into a public key address, which is the BTC address; second, it is used when calculating the Merkle tree, and sha256 is performed twice for each transaction; third, it is used in mining It is used in the proof of work (PoW) in the process, and the sha256 hash value of the calculated block is less than the difficulty value.