Author: Pieter Wuille 2015-04-17 09:02:19
Published on: 2015-04-17T09:02:19+00:00
It is a common belief that anyone can alter the txid of bitcoin transactions, however, the number of altered txids in practice is not high enough to make it seem like an easy task. It is true that all current bitcoin transactions are malleable, but not by just anyone and not that easily. In past instances, large amounts of malleated transactions have occurred. This is important to note since if a system depends on non-malleability for its security, an attacker who stands to gain financially from malleation may attempt to do so. If a transaction is broadcasted, anyone can alter its txid without invalidating it or needing access to the sender's private keys. All that is required is to see a transaction on the network, modify it slightly, and rebroadcast it quickly. If the modified version gets mined, the original sender would not be able to recognize their own transaction and their change too, if their systems heavily rely on the txid. Having mining power would help with this process. After BIP62, senders will have the option to protect others from malleation, though they will always be able to re-sign themselves.
Updated on: 2023-05-19T20:02:48.147412+00:00