Published on: 2018-02-21T17:27:53+00:00
In a recent discussion on the bitcoin-dev mailing list, the topic of documenting buried deployments using BIPs (Bitcoin Improvement Proposals) was brought up. Buried deployments refer to changes in consensus rules that impact the validity of blocks buried by a sufficient number of blocks in the most-work chain. The question was raised as to whether BIPs are necessary for these types of deployments since they do not require software coordination.While some participants argued against the need for BIPs, noting that buried deployments do not require community and miner coordination, others believed that documentation is important for consensus rules and that the BIPs repository would be a suitable place to host these documents. To prevent an overload of BIPs, related buried deployments could be bundled together.It was emphasized that buried deployments should not be labeled as "soft forks" or "hard forks" since they do not require community and miner coordination. Instead, they should be treated as an independent category. However, it was noted that regardless of their classification, buried deployments cannot prevent massive chain reorganizations in the event of a security breach.The discussion then delved into the depth assumption required to ensure that buried deployments do not result in a chain split. It was suggested that multiplying the expected number of blocks in two weeks by 10 or 20 could be an appropriate lower bound. There was also debate over whether the threshold of 25,000 blocks is an objective measure to avoid a chain split.Furthermore, there were differing opinions on whether a massive chain reorganization must occur off of a block in the very past for a chain fork to happen due to a buried deployment, or if a buried deployment is a subjective subcategory of a hard fork. It was acknowledged that in the unlikely event of such a large chain reorganization, Bitcoin's general security assumptions would be violated regardless of the presence of a buried deployment.Marco Falke, a participant in the discussion, defined buried deployments as consensus rule changes that affect the validity of blocks buried by a sufficient number of blocks in the most-work chain. However, there were concerns raised about the assumption that only blocks deeper than the most recent 25,000 need to be validated, as it relies on relying on an authority like Bitcoin Core to determine the checkpoint for tip-25,000.Falke also argued against categorizing buried deployments as soft forks or hard forks, due to their lack of community and miner coordination. He suggested that BIPs for buried deployments could be added to the existing soft fork/hard fork BIP as an Annex, instead of creating separate BIPs. The importance of clear documentation was emphasized to prevent inaccurate analyses and potential consequences.In conclusion, the discussion revolved around the necessity of using BIPs to document buried deployments, whether they should be classified as soft or hard forks, and the depth assumption required to avoid chain splits. It was noted that buried deployments do not require community and miner coordination, but cannot prevent massive chain reorganizations. Clear documentation was highlighted as crucial for understanding the Bitcoin system and ensuring accurate safety analyses.
Updated on: 2023-08-01T22:44:02.071141+00:00