SHA-256

A cryptographic hash algorithm in the SHA-2 family that produces a 256-bit digest.

PLAIN-ENGLISH DEFINITION

In more detail

The 256 describes the output length, not the input's size. Bitcoin uses SHA-256 in several constructions, including applying it twice to a block header for proof of work. The result is a digest for checking data and work rather than an encrypted version of the header.

IN THE WILD

How you might use it

Bitcoin mining code applies SHA-256 twice to a candidate block header, then compares that digest with the proof-of-work target.

WORD NOTES

Written out: Secure Hash Algorithm 256

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By Crypto Dictionary · Published Oct 9, 2026 · Updated Oct 10, 2026

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