The difficulty level of mining Bitcoin , a metric that indicates how hard it is to discover the next hash in a given target range, has finally surpassed 50 billion for the first time.
The difficulty changes every 2016 blocks, or roughly every two weeks, around mid-week. It is now at 51,076,366,303, and automatically projected to reach 51,969,383,096, although this can change.
Difficulty generally increases with time, although it occasionally dips. Changes roughly correlate with those in the total network Hash Rate , the total hashing power of the network.
The hash rate is now roughly 360 PH/s (1 PH = 10^15 hashes, or encryption operations), and has stagnated for much of 2015 after exponential gains in years prior. This is a result of depressed bitcoin prices, which make it less profitable to add hardware to the network, as well as the fact that the network is now saturated with sufficient equipment to maintain equilibrium of slight profitability for most miners.
Likewise, the difficulty level has plateaued as well, sitting between 45 billion and 50 billion for the last five months.
There has been a slight uptick in the prevailing hash rate in recent days, a possible result of the rally in bitcoin prices. Should prices maintain a new floor near $300, we will likely see continued gradual appreciation in hashing power, with additional gains realized if the price rally continues.