Proof of work

A proof-of-work is a solution for difficult (i.e. costly) mathematical task. This solution must be trivial to check whether data satisfies claimed requirements.

Novacoin uses the hashcash method to provide proofs of the work. The difficulty of this work is adjusted so as to limit the rate at which new blocks can be generated by the network to required target spacing rate (from 10 to 30 minutes). Due to the very low probability of successful proof generation, this makes it unpredictable which worker computer in the network will be able to generate the next solution.

How long will it take me to generate a proof-of-work?

No-one can say exactly. But there is an estimation of how long it might take.

Imagine that you have a hardware with 1 MH/s hashing speed. Let's estimate how much time the generation of proof-of-work will take from you in average, with a current Novacoin proof-of-work difficulty.

Difficulty 1.0 is represented by

0x00000000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF

value of target. So, to get a successful proof of work we need to perform 0xFFFFFFFFFFFFFFFF / 0x00000000FFFFFFFF or ~ 4294967297 attempts.

At difficulty 360 we need ~ 360 * 4294967297 or 1546188226920 attempts. If you have 1 MH/s or 1000000 hashes per second then you will be able to scan such amount of hashes within 1546188226920 / 1000000 = 1546188 seconds or 1546188 / 86400 = 17,89 days.