https://en.bitcoin.it/w/api.php?action=feedcontributions&feedformat=atom&user=Perfectfire 2026-05-05T06:11:11Z User contributions MediaWiki 1.43.8 https://en.bitcoin.it/w/index.php?title=Target&diff=15999 2011-09-03T05:30:23Z

<p>Perfectfire: Edited the comment after the link to the difficulty history (hosted on blockexplorer.com) to read &quot;at column 5&quot; instead of &quot;at row 5&quot; since the fifth column is where the difficulty is recorded.</p> <hr /> <div>The '''target''' is a 256-bit number (extremely large) that all Bitcoin clients share. The SHA-256 [[hash]] of a [[block]]'s header must be lower than or equal to the current target for the block to be accepted by the network. The lower the target, the more [[difficulty|difficult]] it is to generate a block.<br /> <br /> It's important to realize that block generation is not a long, set problem (like doing a million hashes), but more like a lottery. Each hash basically gives you a random number between 0 and the maximum value of a 256-bit number (which is huge). If your hash is below the target, then you win. If not, you increment the nonce (completely changing the hash) and try again. <br /> <br /> For reasons of stability and low latency in transactions, the network tries to produce one block every 10 minutes. Every 2016 blocks -- which should take two weeks if this goal is kept perfectly --, every Bitcoin client compares the actual time it took to generate these blocks with the two week goal and modifies the target by the percentage difference. This makes the proof-of-work problem more or less difficult. A single retarget never changes the target by more than a factor of 4 either way to prevent large changes in difficulty.<br /> <br /> === What is the target now? === <br /> * [http://blockexplorer.com/q/hextarget Current target]<br /> * [http://blockexplorer.com/q/getdifficulty Current difficulty], as output by Bitcoin's getDifficulty<br /> * [http://blockexplorer.com/q/probability Current probability of winning a block per attempt]<br /> <br /> === When does the target change next? ===<br /> <br /> * [http://blockexplorer.com/q/nextretarget Next retarget]<br /> <br /> === What has the target been in the past? ===<br /> <br /> * [http://blockexplorer.com/q/nethash Difficulty history, (at column 5)]<br /> * [http://www.bitcoin.org/smf/index.php?topic=2345.msg31405#msg31405 Re: difficulty over time data?]<br /> * [http://bitcoin.sipa.be/ Bitcoin network graphs] <br /> <br /> === What is the maximum target? ===<br /> 0x00000000ffff0000000000000000000000000000000000000000000000000000<br /> <br /> Since a lower target makes Bitcoin generation more difficult, the maximum target is the ''lowest'' possible [[difficulty]].<br /> <br /> [[Category:Technical]]<br /> [[Category:Vocabulary]]</div>

Perfectfire