Candidate Block

A candidate block is a temporary block prepared by miners in a blockchain network, containing a combination of transactions that have not yet been confirmed as a permanent part of the blockchain. Miners filter transactions from the memory pool (mempool), organize them into candidate blocks, and then compete through consensus mechanisms such as Proof of Work (PoW) or Proof of Stake (PoS) to have their candidate block added to the blockchain. The concept of candidate blocks originated from the design of the Bitcoin network. When designing Bitcoin, Satoshi Nakamoto created a mechanism allowing participants in the network to compete for adding new transactions to the distributed ledger. When miners begin mining a new block, they construct a candidate block including the hash of the previous block, the current timestamp, a nonce, and a list of transactions selected from the transaction pool. Miners typically prioritize transactions with higher fees to maximize their potential rewards. The working mechanism of candidate blocks revolves around consensus algorithms. In a Proof of Work system, miners must solve a complex cryptographic puzzle, finding a nonce that makes the block hash meet specific conditions (such as beginning with a certain number of zeros). Once a solution is found, the miner immediately broadcasts the candidate block. Other nodes in the network verify the validity of the solution and, if valid, accept the block and add it to their copies of the blockchain, at which point the candidate block becomes a confirmed block. In Proof of Stake systems, validators are chosen to create new blocks based on the amount of tokens they hold and have staked, rather than by solving computational puzzles. As blockchain technology evolves, so too does the candidate block mechanism. Many next-generation blockchain networks are implementing more efficient consensus algorithms, such as Delegated Proof of Stake (DPoS) and Practical Byzantine Fault Tolerance (PBFT), which change how candidate blocks are processed, increasing transaction throughput and confirmation speed. In the future, as scaling solutions like sharding, sidechains, and layer-2 networks become more widely adopted, the handling of candidate blocks will become more sophisticated and efficient, further enhancing the performance and user experience of blockchain networks. As a core component of blockchain consensus mechanisms, candidate blocks play a crucial role in ensuring network security, preventing double-spending, and maintaining transaction order. They are not only a necessary step in the process of transaction submission and confirmation but also the foundation for miners to earn block rewards and transaction fees. Understanding how candidate blocks work helps grasp the essence of blockchain technology and the operational mechanisms of blockchain networks.