Difficulty adjustment scheme

A lot of you have been wondering how we would implement a switch from PoW to PoS in time for Serenity. This will be handled by the newly introduced difficulty adjustment scheme, which elegantly guarantees a hard-fork point in the next 16 months.

It works as follow: starting from block 200,000 the difficulty will undergo an exponential increase which will only become noticeable in about a year. At that point (just around the release of the Serenity milestone), we’ll see a significant increase in difficulty which will start pushing the block resolution time upwards.

So, a year on, the network will continue to be useful for roughly 3-4 months, but eventually will reach an ‘Ice Age’ of sorts: the difficulty will simply be too high for anyone to find a block. This will allow us to introduce PoS, perhaps via Casper, if it proves itself.