Author: jl2012 at xbt.hk 2015-09-29 15:59:05
Published on: 2015-09-29T15:59:05+00:00
In a discussion on bitcoin-dev, Jonathan Toomim of Toomim Bros notes that SPV clients will continue to function normally after the upcoming softfork, but will be susceptible to double-spending attacks that upgraded nodes will reject. The attack can be performed for as long as someone mines with the old version. Satoshi recommended 6 confirmations in the whitepaper, and those who do not follow his advice are taking their own risk. This is only true if an SPV client naively follows the longest chain without looking at the block version, making it vulnerable to basic fraud detection mechanisms. Additionally, if an attacker thinks they could get more than 25 BTC of double-spends per block, they might choose to mine with the obsolete version to trick SPV clients and fully verifying wallets on the old version. However, this point is irrelevant as SPV users are always vulnerable to such double-spending attacks if they blindly follow the longest chain and accept 1-confirmation. Overall, the fiat currency system may be safer for them.
Updated on: 2023-06-10T23:11:51.753186+00:00