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Avalanche Effect Target

A good hash flips about half its output bits when one input bit changes.

Formula

E[\Delta] = \frac{n}{2}

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Variables

E[Δ]Expected bits changed

nOutput size (bits)

Example

256-bit hash: ~128 bits should flip per input change

Did You Know?

The avalanche effect is why changing a single comma in a document utterly transforms its SHA-256 fingerprint.

cryptography hash avalanche

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