Author: Dario Sneidermanis 2015-06-21 02:23:27
Published on: 2015-06-21T02:23:27+00:00
On June 19, 2015, Bitcoin expert Peter Todd announced that F2Pool, the largest mining pool with 21% of hashing power, had enabled full replace-by-fee (RBF) support. This means that transactions conflicting with other transactions would be replaced by new ones paying a higher fee. However, average users' wallets lack the ability to detect double-spends of unconfirmed transactions when connected to RBF or Bitcoin XT nodes, and wallets with RBF support are not yet available. While this development has little impact on businesses using their own node to verify transactions, those using payment processors/transaction APIs such as BitPay, Coinbase, and BlockCypher may accept unconfirmed transactions that may not be guaranteed by the payment processor.Miners who support RBF will have advantages in reducing pressure to increase block size and making use of limited blockchain space more efficiently. However, Todd warns that this support would also bring serious threats to the existing level playing field that miners operate in. For decentralized wallets, there is no reliable way of knowing whether connections give an accurate view of what transactions miners know about. The only serious attempt to fix this problem for decentralized wallets that has been actually deployed is Andresen/Harding's double-spend relaying, implemented in Bitcoin XT.The article "Tampering with the Delivery of Blocks and Transactions in Bitcoin" was published on Cryptology ePrint Archive on June 10th, 2015 by Arthur Gervais, Hubert Ritzdorf, Ghassan O. Karame, and Srdjan Capkun. The authors discuss the possibility of tampering with the delivery process of blocks and transactions in the Bitcoin network, which could lead to double-spending attacks and other security vulnerabilities. They propose implementing a new protocol prioritizing the delivery of valid blocks and transactions over invalid ones. Nodes would need to verify incoming blocks and transactions before forwarding them to other nodes in the network. The authors also discuss potential challenges, such as the increased risk of denial-of-service attacks and the need for additional resources to support the verification process.Centralized wallets' solutions being deployed, planned, and proposed are harmful, and even represent serious threats to Bitcoin's decentralization. Confidence factors, which involve measuring transaction propagation and connecting to pools directly via the getblocktemplate protocol, waste significant network and miner resources and do not work very well. Transaction processing contracts with miners involve signing contracts with as much of the hashing power as possible to get the transactions they want mined and double-spends rejected. However, there are still serious problems with this approach.The article was shared on the Bitcoin-development mailing list for discussion and feedback from the community.
Updated on: 2023-06-09T23:50:52.721437+00:00