Pull request: https://github.com/bitcoin/bitcoin/pull/534
Denial-of-service prevention: orphan blocks The attack this prevents: Generate valid "orphan" blocks and send them to a bitcoin node. Orphan blocks are blocks that are not in the main blockchain, and before this patch the bitcoin client would store an arbitrary number of them in memory, in case they later became part of the main chain. Two checks are added: 1) Orphan blocks before the last blockchain lock-in are rejected, and if the node sends enough of those obviously-not-part-of-the-main-chain blocks it will be disconnected and banned. 2) Orphan blocks must have a plausible proof-of-work. It is impossible for a difficulty 1.0 block to follow a difficulty 1-million block (it would take at least 19 months for difficulty to drop from 1-million to 1). Orphan blocks with too-low proof-of-work are ignored, and if a node sends ten of them it is disconnected/banned. Requiring plausible proof-of-work for orphan blocks will make this attack too expensive to attempt (you would have to generate valid blocks at current difficulty). -- -- Gavin Andresen ------------------------------------------------------------------------------ All the data continuously generated in your IT infrastructure contains a definitive record of customers, application performance, security threats, fraudulent activity and more. Splunk takes this data and makes sense of it. Business sense. IT sense. Common sense. http://p.sf.net/sfu/splunk-d2dcopy1 _______________________________________________ Bitcoin-development mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/bitcoin-development
