SHA-256 Hash Generator for Blockchain & Bitcoin
Quick Answer: Bitcoin and many blockchains use SHA-256 (specifically double-SHA256 for block headers) as their proof-of-work hash function. Merkle trees in blocks also use SHA-256 to create tamper-evident transaction summaries.
FAQ
What is double SHA-256?
Bitcoin applies SHA-256 twice: SHA256(SHA256(data)). This was chosen to prevent length-extension attacks that affect single-pass SHA-256.
Why does Bitcoin use SHA-256?
SHA-256 was chosen for its security margin, wide availability, and resistance to known cryptographic attacks when Bitcoin was designed in 2008.