Quote from: JorgeStolfi on March 21, 2016, 04:55:24 AM

Quote from: 2112 on March 20, 2016, 03:43:42 PM

Quote from: JorgeStolfi on March 20, 2016, 01:24:31 AM

(Note that there is no way for a miner to determine when a transaction T1 was signed. Even if it spends an UTXO in a transaction T2 that was confirmed only yesterday, it is possible that both T1 and T2 were signed a long time ago.)

Your argument is technically specious. Transactions in Bitcoin have 4 byte version field, that gives us potential for billions of rule-sets to apply to the old transactions. The correct question to ask: why this wasn't and isn't changed as the rules gets changed?

I am not sure if I understood your comment. Miners cannot apply old semantics when the transaction has an old version field, because that field can be faked by the clients to sabotage the change. E.g., suppose that the change imposed a mininum output amount of 0.0001 BTC as a way to reduce spam attacks on the UTXO database. An attacker could frustrate that measure by issuing transactions with the pre-fork version tag. Does that answer your comment?

You started writing really weird conflated stuff. What do fees have to do with transaction syntax?

The version field should be used to clearly describe syntax rules governing the transaction format.

The amount of fees doesn't change the syntax, so doesn't require change of the version.

The existing client already has "misbehavior" score to disconnect itself from other peers that try to abuse it in various ways. There's no point to invent new mechanisms to do it. All that could be possibly required is to tune the specific values for various misbehavior demerits.