Crypto Fundamentals
Hash Functions
A hash function converts arbitrary input data into a fixed-size digest.
1 | "hello" |
Important properties:
- The same input always produces the same hash.
- A tiny input change produces a very different hash.
- Recovering the original input from the hash should be computationally infeasible.
- Finding two different inputs with the same hash should be extremely difficult.
Blockchains use hashes for transaction IDs, block linking, Merkle trees, and data integrity.