Author: jl2012 at xbt.hk 2015-11-01 17:28:39
Published on: 2015-11-01T17:28:39+00:00
The question of whether backward compatibility is necessary for non-standard transactions has been raised. This applies to time-locked transactions with outputs in the form of HASH160 EQUAL, which were frozen after the deployment of BIP16. The same also applies to all OP codes disabled by Satoshi. Making any softfork related to the script system would be impossible if backward compatibility is a requirement. It is important to note that non-standard transactions and scripts may become invalid in the future. Gavin Andresen posed a question on the bitcoin-dev mailing list in 2015, asking whether it should be a requirement that any one-megabyte transaction valid under existing rules should also be valid under new rules. He argued that there could be expensive-to-validate transactions created and given a lockTime in the future stored somewhere safe, and changing validation rules to be more strict so that those transactions are invalid would be an unacceptable confiscation of funds. However, he acknowledged that it was unlikely that there were any such large, timelocked transactions. The requirement should not apply to transactions larger than 100,000 bytes, which are not considered standard and are not relayed or mined. Gavin Andresen had to consider this question when implementing BIP101/Bitcoin XT when deciding on a limit for signature hashing.
Updated on: 2023-06-11T00:46:23.007890+00:00