Key Stretching

Updated 31 Jul 2026

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def
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  strengthening a weak key by running it through multiple additional processes, making it much more resistant to brute-force attacks even though the original key itself is small
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how it works
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  e.g., hash a password, then hash the result of that hash, and continue repeating — also called key strengthening
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  a brute-force attacker now has to reverse each of those additional hashing rounds, not just one, which costs them far more time
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related
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  Salting
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  Hashing
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  Key Length
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cards
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  What is key stretching, and what's another name for it?
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    Repeatedly hashing a password (hash the hash, and continue) to make a weak key much harder to brute-force; also called key strengthening

Linked references 2