Simple Replay Protection for BU coins

[arnoudk]

Exchanges have demanded that BU implements replay protection.

All they would have to do to achieve this is to get a tx input that is valid on one chain but not on the other. Deliberately spending the same coins to a different output address on both forks.

Then the exchange could mix all their txs on the bitcoin unlimited chain with a 1 satoshi input that is invalid on the bitcoin core chain.

Once that has confirmed you can spend the bitcoin core coins on their chain without risk of being confirmed on the bu chain.

Bitcoin Unlimited should not change tx formats. All old txs should be valid. If someone has a time locked tx somewhere (but not the private key) he should be able to broadcast this tx on the bu chain. Excluding that is not acceptable.

I don't see how exchanges would find mixing a tx input hard.

Maybe all Bitcoin Unlimited needs to do is set up a faucet giving away 1 BU satoshi to whoever wants one. They could even give away private keys for 1 satoshi addresses. No one would steal them as tx fees are higher than the 1 satoshi value. Import the 1 satoshi address, spend all funds to yourself, and voila.

[Windowly]

Yes, as a Bitcoin Unlimited member I probably would vote against replay protection. If Bitcoin Unlimited has 75 or 80% of the hashpower by the white paper's definition they are the longest chain and they are bitcoin.