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In the Witnet network protocol, a Block is formatted as follows:

Field Type Description
block_header BlockHeader The header of the block
proof LeadershipProof A miner-provided Proof of Eligibility
txns repeated Transaction A keyed signature of the block header

A non-empty list of transactions is always provided because the mint transaction should always be included.

Block header structure

The block header (BlockHeader) is composed of the following fields:

Field Type Description
version uint32 The block version number indicating the block validation rules
beacon CheckpointBeacon A checkpoint beacon for the epoch that this block is closing
hash_merkle_root Hash A 256-bit hash based on all of the transactions committed to this block

Checkpoint beacon structure

The checkpoint beacon (CheckpointBeacon) is composed of the following fields:

Field Type Description
checkpoint fixed32 The serial number for this epoch
hash_prev_block Hash The 256-bit hash of the previous block

Proof of Eligibility

The Proof of Eligibility (LeadershipProof) signature is computed by simply signing the beacon field of the block header using the same private key as for the signature.

Signature structures are defined in the Signature section.