Social Consensus, Nakamoto Consensus
Consensus in the context of blockchain technology refers to the process used by network nodes to agree on the state of the distributed ledger. This agreement is crucial to ensure that all participants have a consistent view of the data stored on the blockchain, despite the decentralized nature of the network.
For instance, in the Bitcoin network, nodes reach consensus on the state of the blockchain by following the longest chain rule, which states that the valid chain is the one with the most accumulated proof of work.
2. social consensus
Social Consensus refers to the agreement among the community members, including developers and miners, over the direction of the protocol's development and how transactions should be included in blocks. While this often aligns with the technical consensus mechanism (like Nakamoto Consensus), differences can lead to contentious forks.
The Bitcoin Cash hard fork in 2017 is an example of a situation where social consensus led to a split in the network. A segment of the community disagreed with the proposed SegWit upgrade and decided to create a new version of the blockchain with different rules.
3. nakamoto consensus
Nakamoto Consensus is a fundamental concept in Proof of Work (PoW) blockchains that provides security and decentralization. It is a rule where miners follow the chain with the most accumulated Proof of Work (PoW) at any given moment, for a given ruleset. This incentivizes miners to cooperate and act honestly, building upon the same ledger as the rest of the network instead of splitting off.
3.1 Double spend attempt
If a miner tries to mine a double-spend transaction in a block against the rest of the network, the honest chain will grow faster than the dishonest chain unless the miner can accumulate more proof of work than all other miners combined. This forces the dishonest miner to either waste resources mining their minority chain or join the longest chain and act honestly, indirectly punishing them for violating Nakamoto Consensus.
3.2 Orphan blocks
When multiple miners discover a block nearly simultaneously, each node will use the block they received first as the valid one, causing a temporary fork. Once a second block is found, that chain becomes the longest, and all miners switch to building on that one. In this case, one miner loses their block reward, even though they acted honestly.
4. consensus mechanisms
Besides Nakamoto Consensus, there are other consensus mechanisms used in different blockchain networks. These include Proof of Stake (PoS), Delegated Proof of Stake (DPoS), and Byzantine Fault Tolerance (BFT), among others. Each has its own advantages and trade-offs in terms of security, decentralization, and scalability.
Ethereum, for instance, is transitioning from Proof of Work (PoW) to Proof of Stake (PoS) to improve scalability and energy efficiency. In PoS, validators are chosen to create new blocks based on their stake in the network, rather than their computational power.
* All terms and definitions may update as the Cryptionary improves.