Author: George Balch 2018-01-29 21:53:06
Published on: 2018-01-29T21:53:06+00:00
A researcher has made a simple analysis of Bitcoin timestamp accuracy and suggested ways to improve it. The timestamp is not the time that the block was created, but rather the time that the miner started to try to mine the block. Timestamps may also be used as a source of variety for hashes, making the exact meaning of its value unclear. Timestamps are not necessary to avoid double-spending, as simple ordering of blocks is sufficient. Timestamps are included in Bitcoin's protocol only to adjust the difficulty of Proof of Work (PoW). The Bitcoin protocol defines “network time” for each node, which is the median time of the other clients if certain conditions are met. New blocks are accepted by the peers if their timestamps satisfy certain rules. The first rule supplies a 2-hour upper bound for timestamp accuracy, but the second rule doesn't give a tight lower bound unless assumptions are made about the median. If miners have no motive to increase difficulty artificially, then the PoW adjusting algorithm yields a second mechanism of accuracy control. A possible improvement is to consider exchanging average with standard deviation in the difficulty adjustment formula to better mirror changes in hash power along the interval and disable the option to manipulate timestamps without affecting the difficulty. However, this change requires a hardfork and won't happen anytime soon.
Updated on: 2023-06-13T00:21:38.802117+00:00