Published on: 2017-11-28T10:48:28+00:00
The proposed Bitcoin Core implementation of BIP159 aims to allow pruned nodes to serve a limited number of historical blocks, instead of none at all. However, there is a concern that this would be wasteful as pruned nodes with 10-100 GB of storage would only be able to share the most recent 288 blocks.To address this, a future extension of the BIP could allow more flexibility by limiting the number of choices to e.g. 288 + 1000 * 2^n. This would provide node operators with the option to choose a greater prune depth if they are willing to accept the increased risk of fingerprinting.Upgraded nodes may need a new message type to communicate the chosen prune depth. It is suggested that waiting for BIP150 would be appropriate, as it would exempt whitelisted peers from the anti-fingerprinting measure. However, restricting it to just whitelisted peers may not be desirable.In order to improve the BIP itself, minor suggestions have been made. These include adding links to mailing list discussions in the reference section and explaining that 288 is not just the minimum limit for Bitcoin Core, but also represents the bulk of traffic.Currently, virtually no one sets any parameter other than the minimum for pruning. However, in the future, further pruning identifying bits will be set so that nodes can answer for their blocks. Defining additional levels has been delayed due to insufficient experience and concerns about interaction with other proposals.Fetching additional blocks is seen as less significant due to the abundance of nodes that serve anything on the network. Additionally, the probability of fetching older blocks becomes close to uniform after a few weeks, and these fetches are mainly for newly initializing nodes.Overall, the proposed implementation of BIP159 seeks to balance the desire to serve archived blocks with the need to prevent fingerprinting. Future extensions and improvements are being considered to provide more flexibility and enhance the functionality of pruned nodes in the Bitcoin network.
Updated on: 2023-08-01T22:10:00.226753+00:00