On Thu, Feb 23, 2017 at 7:15 PM, Peter Todd <pete@petertodd.org> wrote:

Glad we're on the same page with regard to what's possible in TXO commitments.

Secondly, am I correct in saying your UTXO commitments scheme requires random
access? While you describe it as a "merkle set", obviously to be merkelized
it'll have to have an ordering of some kind. What do you propose that ordering
to be?

The ordering is by the bits in the hash. Technically it's a Patricia Trie. I'm using 'merkle tree' to refer to basically anything with a hash root.

Maybe more specifically, what exact values do you propose to be in the set?

That is unspecified in the implementation, it just takes a 256 bit value which is presumably a hash of something. The intention is to nail down a simple format and demonstrate good performance and leave those semantics to a higher layer. The simplest thing would be to hash together the txid and output number.