Proof of stake

Proof-of-stake is term referring to the use of currency itself (ownership) to achieve certain goals. In the NovaCoin proof-of-stake is used to provide mining and transaction processing on a par with proof-of-work.

Novacoin uses the mixed Coin-Age/CoinDayWeight approach to provide proofs of the stake. The proof-of-stake difficulty is adjusted so as to limit the rate at which new blocks can be generated by the network to 10 minutes target spacing rate. Due to the very low probability of successful proof generation, this makes it unpredictable which computer in the network will be able to generate the next solution.

How it's supposed to work?

It's performed through scanning all available inputs in order to find lucky one which satisfies this condition:

SHA256(SHA256(KERNEL)) < CoinDayWeight *  NetworkTarget

Miner has to find a SHA256 hash that is under the target value. Target is derived from network target using CoinDayWeight parameter.

Kernel structure

Field	Type	sizeof	Description
nStakeModifier	unsigned long int	8	Deterministic [[modifier
nTimeBlockFrom	unsigned int	4	Timestamp for block which provided previous transaction, prevent nodes from guessing a good timestamp to generate transaction for future advantage.
nTxPrevOffset	unsigned int	4	Offset of previous transaction inside the block, used to reduce the chance of nodes generating kernel coinstake at the same time.
nTxPrevTime	unsigned int	4	Timestamp of previous transaction, used to reduce the chance of nodes generating coinstake kernel at the same time.
nPrevoutNum	unsigned int	4	Output number of previous transaction, used to reduce the chance of nodes generating coinstake kernel at the same time.
nTimeTx	unsigned int	4	Current timestamp