3 ms·
The difficulty D defines the expected number of double SHA256 hashes E[H] = 2^32 * D that must be computed on average per block to meet the difficulty target, w
by tromp 5y ago
The difficulty D defines the expected number of double SHA256 hashes E[H] = 2^32 * D that must be computed on average per block to meet the difficulty target, which according to the average efficiency of mining ASICs implies an average amount of energy to be used.
- mistrial9 5y agofirst of all, difficulty D is a float, and there are no floats in the actual computation. Second, a float is not a number of hashes. bzzzzt edit- In plain English, this explanation is incorrect because it relies on floating point number D. Difficulty D is a convenience representation as float of the ratio of two very large integers; one of those large integers is the fixed MAX Target. The other vary large integer is varied by a prescribed formula, once every two weeks.
- tromp 5y agoIndeed; as [1] says: What is the formula for difficulty? difficulty = difficulty_1_target / current_target (target is a 256 bit number) I simply used the fact that the difficulty_1_target (the MAX Target as you call it) needs an expected 2^32 double SHA256 hashes to meet. [1] https://en.bitcoin.it/wiki/Difficulty https://en.bitcoin.it/wiki/Difficulty
- mistrial9 5y ago> expected 2^32 double SHA256 hashes yes, expected by.. some approximation of the current hardware to find the solution.. We are not at the answer yet
- tromp 5y agoNothing to do with hardware. Quoting again from that bitcoin wiki page: The highest possible target (difficulty 1) is defined as 0x1d00ffff, which gives us a hex target of 0x00ffff * 2**(8*(0x1d - 3)) = 0x00000000FFFF0000000000000000000000000000000000000000000000000000 As you can see a random hash has a chance of close to 2^-32 to satisfy that target.
- mistrial9 5y ago> Nothing to do with hardware use a pencil?