[bitcoin-dev] SHA1 collisions make Git vulnerable to attakcs by third-parties, not just repo maintainers

Steve Davis steven.charles.davis at gmail.com
Sun Feb 26 16:53:29 UTC 2017

> On Feb 26, 2017, at 1:36 AM, Pieter Wuille <pieter.wuille at gmail.com> wrote:
> Typical hash function breaks produce collision attacks, while a preimage attack is needed to reduce single-key address security.

Thank you Pieter - that was really helpful. I realize now that I was thinking of a preimage attack but had mistakenly assumed that the birthday bound applied...

So the unit operation: [genkeypair; ripemd160(sha256(pubkey));check_utxoset] would need to be performed 2.9*10^42 and not (as I had first calculated) 2.4*10^18. 

Oops. My bad.

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