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SHA-256

A 256-bit cryptographic hash function from the SHA-2 family, used extensively in Bitcoin and security systems.

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Definition

A 256-bit cryptographic hash function from the SHA-2 family, used extensively in Bitcoin and security systems.

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Why it matters

Cryptography provides the mathematical foundation for keys, signatures, privacy, integrity, and verification.

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How it works

The algorithm processes the input data through multiple rounds of logical, bitwise operations. It compresses the data into a fixed-length string of hexadecimal numbers. The design ensures that even a tiny alteration in the source results in a drastically different, unpredictable output hash.

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Real-world example

Bitcoin mining and the SHA-256 hashing standard used by the TLS protocol for secure web traffic.

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Advantages

  • Strong collision resistance
  • High data integrity
  • Computational efficiency

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Limitations

  • Vulnerable to massive brute-force attacks
  • Not suitable for password storage alone
  • Quantum computing threats

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Common misconceptions

  • Many people incorrectly call it an encryption algorithm, but it is actually a one-way hash function.
  • Some mistakenly believe it can be decrypted to reveal the original input.
Canonical knowledge ID: glossary:sha-256