On Thu, Jan 7, 2016 at 6:52 PM, Pieter Wuille <pieter.wuille@gmail.com> wrote:

Bitcoin does have parts that rely on economic arguments for security or privacy, but can we please stick to using cryptography that is up to par for parts where we can? It's a small constant factor of data, and it categorically removes the worry about security levels.

Our message may have crossed in the mod queue:

"So can we quantify the incremental increase in security of SHA256(SHA256) over RIPEMD160(SHA256) versus the incremental increase in security of having a simpler implementation of segwitness?"

I believe the history of computer security is that implementation errors and sidechannel attacks are much, much more common than brute-force breaks. KEEP IT SIMPLE.

(and a quibble: "do a 80-bit search for B and C such that H(A and B) = H(B and C)" isn't enough, you have to end up with a C public key for which you know the corresponding private key or the attacker just succeeds in burning the funds)

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Gavin Andresen