Block header

The block header is a metadata structure which is used to link blocks in the blockchain.

Block header has a size of 80 bytes and consists of 6 fields:

FieldTypesizeofDescriptionUpdated when
nVersionunsigned int4Block header versionYou upgrade the software and it specifies a new version
hashPrevBlockunsigned char[]32Previous block header hash, used to link block headers into listNew block is accepted
hashMerkleRootunsigned char[]32Merkle tree hash, used to link block header and block contentsTransactions pool is updated
nTimeunsigned int4Unix timestampEvery few seconds for Proof-of-Work, every successful attempt for Proof-of-Stake
nBitsunsigned int4Compact representation of claimed proof difficultyThe difficulty is adjusted
nNonceunsigned int4Attempts counter for Proof-of-WorkNew Proof-of-Work hash tried, or never with Proof-of-Stake

Each block header is required to satisfy the claimed proof.

BasisNetwork basicsClient softwareRelated pages