The Truth behind BIP 16 and 17 (important read)

[fivemileshigh]

* Disclaimer: I don't think that BIP17 is better than BIP16. Both are ugly hacks. I will support one only if most other miners will.

Tycho, I mean this with all the kindness and respect I can possibly muster:

If you think both are ugly, make your case and stand by it. "Just doing what everybody else is doing" is groupthink. Don't be a sheep. Nothing good or worth having lies that way.

[ByteCoin]

It is already cryptographically possible to have two or more devices each have access to a portion of a private key, and be able to combine these portions to spend funds in such a way that no device gains access to any more of the private key than it already had, correct?

AIUI, no.

Yes it's possible. As far as I can recall, you need to use the additive homomorphic property of the Pallier scheme. It has been discussed on the forum before but I can't find the reference.

ByteCoin

[casascius]

RE: 2_Thumbs_Up

That new 'genesis block' would be just as big as the current pruned blockchain, so there is no point in doing it that way. Luckily there is no need: clean and simple P2SH would be easy to do with the current blockchain and transactions. The only challenge would be, apparently, the network-wide upgrade process.

This may belong in another thread, but I have heard this point made, and I am not sure I agree with it, just doing a mental estimation in my head.

A new genesis block would be the same size as the current pruned blockchain, minus all of the following VERY BIG wastes of space:

• Transaction inputs (these are HUGE: 130+ bytes each, compared to outputs around 30 bytes each) - and are worthless information except for their verification value... when multisig arrives, typical inputs will be double and triple this per transaction.
• Stubs left behind when you prune merkle trees (since you need the full hash of the branches you pruned to be able to verify the hash of what's left of tree, which in many cases these hashes are a decent fraction in size of the transactions they replace)
• Spent outputs of multi-output transactions (which can't be pruned if ANY unspent outputs remain - especially bloatful when you consider, for example, that pools like P2Pool generate huge transactions with numerous penny-sized outputs to pay off miners, of which most but not all get spent... which directly means that most of the space they take up is a waste).

Remove all of this fluff from a pruned block chain, make a "regenesis" block consisting of nothing but unspent outputs, and I bet it's less than a third the size of even a pruned block chain, and less than a tenth or twentieth the size of our current chain (a disparity that increases toward infinity as bitcoin is used - by 2013, this disparity might quadruple).

[finway]

Gonna read this long post someday.

[Atheros]

Remove all of this fluff from a pruned block chain, make a "regenesis" block consisting of nothing but unspent outputs, and I bet it's less than a third the size of even a pruned block chain, and less than a tenth or twentieth the size of our current chain (a disparity that increases toward infinity as bitcoin is used - by 2013, this disparity might quadruple).

Ok, I definitely concede that it would be smaller. All of those things individual miners can do on their own. The chain wouldn't be verifiable anymore but we basically threw that condition out of the window when we made a re-genesis block. I'm sure miners will be doing this before long as long as the full block chain is still available in a distributed manner.