Re: [Bitcoin-development] Lets discuss what to do if SHA256d is actually broken

Charlie 'Charles' Shrem writes: > Hey Rusty, > > This is intriguing, do you have a writeup somewhere I can read more about ? OK, ignore the FIXMEs, but I rehashed my stupid sim code, added some graphs to the (clearly unfinished) paper and uploaded it to github: https://github.com/rustyrussell/bi

Re: [Bitcoin-development] Lets discuss what to do if SHA256d is actually broken

Hey Rusty, This is intriguing, do you have a writeup somewhere I can read more about ? Thanks, Charlie CharlieShrem.com | *Please **encrypt messages with my PGP key * On Tue, Jun 3, 2014 at 8:45 AM, Rusty Russell wrote: > Luke Dashjr writes: > > On Tuesday

Re: [Bitcoin-development] Lets discuss what to do if SHA256d is actually broken

Luke Dashjr writes: > On Tuesday, June 03, 2014 4:29:55 AM xor wrote: >> Hi, >> >> I thought a lot about the worst case scenario of SHA256d being broken in a >> way which could be abused to >> A) reduce the work of mining a block by some significant amount >> B) reduce the work of mining a block

Re: [Bitcoin-development] Lets discuss what to do if SHA256d is actually broken

There is a relevant post from Satoshi on this: https://bitcointalk.org/index.php?topic=191.msg1585#msg1585 Quote: "If SHA-256 became completely broken, I think we could come to some agreement about what the honest block chain was before the trouble started, lock that in and continue from there w

Re: [Bitcoin-development] Lets discuss what to do if SHA256d is actually broken

On 6/3/2014 12:29 AM, xor wrote: > -BEGIN PGP SIGNED MESSAGE- > Hash: SHA256 > > Hi, > > I thought a lot about the worst case scenario of SHA256d being broken in a way > which could be abused to > A) reduce the work of mining a block by some significant amount > B) reduce the work of mining

Re: [Bitcoin-development] Lets discuss what to do if SHA256d is actually broken

An attack on the mining difficulty algorithm does not imply violation of the typical security properties of a cryptographic hash function*. Assume someone discovers a method which makes it far easier to discover new blocks, this method: may or may not be implementable by the current SHA256 ASIC ha

Re: [Bitcoin-development] Lets discuss what to do if SHA256d is actually broken

On Tuesday, June 03, 2014 4:29:55 AM xor wrote: > Hi, > > I thought a lot about the worst case scenario of SHA256d being broken in a > way which could be abused to > A) reduce the work of mining a block by some significant amount > B) reduce the work of mining a block to zero, i.e. allow instant m