Quote from: jgarzik on March 21, 2011, 01:50:22 AM

Because scripting is mostly disabled and difficult to get right in a secure way, I would rather just strip it out, for btc2.

You can do signed validation and multi-in, multi-out without a script engine.

These use cases don't use multi-in or multi-out. They have multiple pubkeys on a single output. This allows multiple parties to cooperate in a transaction. There's no way to implement escrow and such without scripts.

I agree that there should be a careful security review, but I don't think it's that difficult. The main thing is to do validation of length and bounds, and have multiple reviewers of the code.

I went over the code and I don't actually see that many disabled operations. Unless I am missing something, currently all clients accept blocks with complex scripts. They only reject mining them. So a miner could insert complex scripts into the block chain. The security of the system as it currently stands does depend on making sure the scripting system is secure.

One thing I do notice is that OP_MUL doesn't have a bounds check. Clients can be crashed with a few OP_DUP + OP_MUL in an otherwise valid block. This seems to currently be a security issue. I can do a more thorough review in a few days.