Published on: 2016-05-03T02:05:11+00:00
Kristov Atlas, a developer, has shared a sample of 16 transaction IDs from the BitcoinTalk thread on JoinMarket. These transactions reveal an average ratio of 1.38 outputs to inputs. Atlas points out that this situation is unsustainable because eventually the change needs to be combined again or else the unspent transaction outputs (UTXOs) will not get spent. However, the advantage of segwit discount for CoinJoin transactions is that it makes spending UTXOs cheaper and recovers funds that would otherwise be lost to dust.In a discussion on bitcoin-dev about the impact of the 75% Segregated Witness subsidy on CoinJoin transactions and similar ones, Kristov Atlas raises the question of whether this subsidy serves as a financial disincentive against CoinJoin transactions. It is noted that CoinJoin transactions do not necessitate any specific behavior that would be affected by this subsidy. Normal transactions spend a coin and create a payment of a specified amount along with change, and CoinJoins are no different in this regard. While users may sometimes split their outputs to enhance privacy, resulting in the "more outputs" effect, this alone does not increase costs under segwit. The total cost for a user to create an output paying themselves includes both the cost of creation and the eventual cost of spending it. Segwit's cost calculation improvements shift some relative cost from spending to creation, but the same users pay for both. It is important to consider where other transactions are when evaluating the output to input ratio for self-sends. For example, in block 409711, there is an average of 1.4647 outputs per input, although this figure varies across different blocks.Regarding the sample of the 16 transaction IDs posted in the JoinMarket thread on BitcoinTalk, which showed an average ratio of 1.38 outputs to inputs, it is pointed out that it is strange to state this as a fact right after providing data that disproves it. The author also requests that people refrain from discussing Schnorr signatures since they are not currently part of any immediate roadmap. However, it is mentioned that Schnorr signatures for Bitcoin have been in development for years and are one of the first proposed uses of segwit versioning. Schnorr multisignature signature aggregates would significantly reduce the cost of CoinJoin transactions, and if there were any disincentive, it would be eliminated by planned use of segwit versioning.The impact of the 75% Segregated Witness subsidy on CoinJoin transactions and similar ones has raised questions. This subsidy makes signature data, which does not affect the size of the unspent transaction output (UTXO) set, 75% cheaper than data that does impact the UTXO set size. The expectation is that users will prefer transactions that minimize the impact on the UTXO set in order to reduce fees, and developers will design new features that also minimize this impact. While this could potentially act as a disincentive against CoinJoin transactions, it remains unclear if there is any evidence to support this claim. It is worth noting that traditional CoinJoin transactions typically create around two UTXOs for every one they consume, unless address reuse is involved. The author emphasizes that they do not wish to discuss Schnorr signatures in replies, as they are not currently part of any immediate roadmap.
Updated on: 2023-08-01T18:04:29.439589+00:00