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Breaking Bitcoin's hash algorithm would require a feasible pre-image attack on SHA-256. Such a thing would have far greater consequences than forcing Bitcoin to
by ggreer 11y ago
Breaking Bitcoin's hash algorithm would require a feasible pre-image attack on SHA-256. Such a thing would have far greater consequences than forcing Bitcoin to change its proof-of-work algorithm. Tons of protocols and applications would be rendered insecure. We'd all be scrambling to fix TLS, SSH, IPSec, GPG, and dozens of other key pieces of software. I'm not sure how Debian-based systems would upgrade, since deb packages are verified by SHA-256. In short, it would be utter chaos.
- schmichael 11y agoEvery system you mentioned other than Bitcoin already supports alternatives to SHA-256. There'd be a scramble for sure, but no different than the current steady stream of OpenSSL vulns. Probably less of a scramble than many OpenSSL vulns as SHA-256 could often be disabled via simple config file changes. Bitcoin on the other hand would have to fundamentally change due to miners with ASICs. The code change might be minimal, but the economic, political, and psychological impact would be huge. For miners to lose their entire infrastructure investment in ASICs may cause an unrecoverable drop in hash rate as it takes 2 weeks for difficulty to recalculate.
- Sanddancer 11y agoThis is why SHA-3 exists. If it starts looking feasible that SHA-256 is going to be broken, we already have alternatives. We've already seen TLS et al switch from hashes like MD5 and SHA-1 a few years ago. Pretty much all the other systems have systems in place to migrate in case one part of the validation system is cracked. Bitcoin doesn't, and given the fractured state of the community, having a migration system would be difficult at the very least.