From 9d55050773d57c0e12005e524f2e54d9e622c6e2 Mon Sep 17 00:00:00 2001 From: Mark Friedenbach Date: Wed, 3 Jun 2015 12:55:45 -0700 Subject: Add rules--presently disabled--for using GetMedianTimePast as endpoint for lock-time calculations The lock-time code currently uses CBlock::nTime as the cutoff point for time based locked transactions. This has the unfortunate outcome of creating a perverse incentive for miners to lie about the time of a block in order to collect more fees by including transactions that by wall clock determination have not yet matured. By using CBlockIndex::GetMedianTimePast from the prior block instead, the self-interested miner no longer gains from generating blocks with fraudulent timestamps. Users can compensate for this change by simply adding an hour (3600 seconds) to their time-based lock times. If enforced, this would be a soft-fork change. This commit only adds the functionality on an unexecuted code path, without changing the behaviour of Bitcoin Core. --- src/consensus/consensus.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'src/consensus') diff --git a/src/consensus/consensus.h b/src/consensus/consensus.h index f937844e9f..6d6ce7e099 100644 --- a/src/consensus/consensus.h +++ b/src/consensus/consensus.h @@ -13,4 +13,10 @@ static const unsigned int MAX_BLOCK_SIGOPS = MAX_BLOCK_SIZE/50; /** Coinbase transaction outputs can only be spent after this number of new blocks (network rule) */ static const int COINBASE_MATURITY = 100; +/** Flags for LockTime() */ +enum { + /* Use GetMedianTimePast() instead of nTime for end point timestamp. */ + LOCKTIME_MEDIAN_TIME_PAST = (1 << 1), +}; + #endif // BITCOIN_CONSENSUS_CONSENSUS_H -- cgit v1.2.3