On Wed, Apr 10, 2013 at 05:58:10PM +0200, Jorge Timón wrote: > On 4/10/13, Peter Todd wrote: > > Oh, and while we're at it, long-term (hard-fork) it'd be good to change > > the tx hash algorithm to extend the merkle tree into the txouts/txins > > itself, which means that to prove a given txout exists you only need to > > provide it, rather than the full tx. > > > > Currently pruning can't prune a whole tx until every output is spent. > > Make that change and we can prune tx's bit by bit, and still be able to > > serve nodes requesting proof of their UTXO without making life difficult > > for anyone trying to spent old UTXO's. The idea is also part of UTXO > > proof stuff anyway. > > I thought about this before, I like the idea very much. > Would such a fork be controversial for anyone? > Would anyone oppose to this for some reason I'm missing? You mean https://bitcointalk.org/index.php?topic=137933.0 ? I would oppose it, and I wrote the above proposal. The code required to implement UTXO fraud proofs is more complex than the entire Bitcoin code base; obviously that much new fork-critical code opens up huge technical risks. As an example, can you think of how UTXO fraud proofs can cause an arbitrarily deep re-org? -- 'peter'[:-1]@petertodd.org