What is Hash Function?
A cryptographic hash function maps arbitrary-size input to a fixed-size output deterministically, irreversibly and with strong collision resistance. Hashes are the workhorse of blockchain: linking blocks, building Merkle trees, deriving addresses and powering Proof of Work.
Why Hash Function matters
Understanding Hash Function is part of building a solid mental model of how Bitcoin, blockchain and Web3 systems actually work. Concepts in the Cryptography category sit at the foundation of the broader stack — get them right and the rest is far easier.
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Related terms
- SHA-256 — The hash function Bitcoin uses everywhere.
- Hash Function — A deterministic function mapping arbitrary input to fixed-size output.
- Merkle Tree — A binary tree of hashes used to summarise data efficiently.
More cryptography terms
- Digital Signature — A cryptographic proof that the holder of a private key authorised a message.
- ECDSA — Elliptic Curve Digital Signature Algorithm.
- Merkle Root — The single hash summarising all transactions in a block.
- Private Key — The secret number that authorises spending from an address.
- Public Key — The shareable counterpart to a private key.
- Zero-Knowledge Proof — Proving you know something without revealing what it is.
- Schnorr Signature — A signature scheme enabling key aggregation.
- Merkle Proof — Compact proof that a transaction is in a block.
Keep exploring
Continue with the full blockchain glossary — 136 terms in total — or read the developer blog and FAQ for deeper context.