Consensus mechanism of block chain

The consensus mechanism of block chain is an important component of block chain, which is related to the operation mode of block chain. Block chain consensus mechanism has the trend of more energy saving, more efficient and fast direction.
POW
Proof-Of-Work
The core of POW is that the greater the computing power, the greater the probability of digging into a block, and the greater the weight of maintaining chain security. Compared with other consensus mechanisms, the POW logic is simple and easy to implement, with a fault tolerance of 50%, and its security has strict mathematical proof.
POS
Proof-of-Stake
POS competition is the balance, popular saying is that the more coins in his wallet, the probability of digging into a block is greater. By the little coin Peercoin first realize, belong to POW and POS mixed consensus, POW for coins, POS for maintenance of network, followers have new coins (Novacoin), black currency (blackcoin) and so on. Nextcoin is a pure POS currency, the implementation is completely different from the Peercoin.
POS2.0
The black community that money may be the age of money to get the network node malicious abuse of higher weights and the successful implementation of double attack, so the release of PPC POS2.0 white paper, made a few details of the optimization to solve some potential safety problems, the most important improvement is used instead of old currency balance. This motivates nodes to keep more coins online, improve system security, minimize attacks, and significantly increase the number of nodes that remain on the network.
POS3.0
The black community currency since further upgrades, launched POS3.0 version, the transaction fees, the difficulty of adjustment to do some optimization, one of the most significant change is the 1% annual interest rate incentives into a fixed amount of reward (each block fixed reward 1.5BLK).
DPOS
A new consensus mechanism for the invention of bits and shares - Delegated Proof-Of-Stake (DPOS), that is, stock ownership certificates. DPOS is easy to understand. A bit stock system treats a token holder as a shareholder. The stockholders vote for 101 delegates, then the representatives take responsibility for generating blocks.