Block Model

An introduction and overview of the VechainThor blockchain block model.

VeChainThor defines a block in Golang as:

// block.go

type Block struct {
	header *Header
	txs    tx.Transactions
}

type Header struct {
	body headerBody
}

type headerBody struct {
	ParentID    thor.Bytes32
	Timestamp   uint64
	GasLimit    uint64
	Beneficiary thor.Address

	GasUsed    uint64
	TotalScore uint64

	TxsRoot      thor.Bytes32
	StateRoot    thor.Bytes32
	ReceiptsRoot thor.Bytes32

	Signature []byte
}

type Transactions []*Transaction

Fields within the headerBody, $\Gamma$, are defined as:

• ParentID - the ID of the parent block.

• Timestamp - the block time

• GasLimit - the maximum amount of gas that all transactions inside the block are allowed to consume

• Beneficiary - the address assigned by the block generator to receive reward (in VTHO)

• GasUsed - the actual amount of gas used within the block

• TotalScore - the accumulated witness number of the chain branch headed by the block. See Trunkfor more detail.
• TxsRoot - root hash of the transaction in the payload

• StateRoot - root hash for the global state after applying changes in this block

• ReceiptsRoot - hash of the transaction receipts trie

• Signature - signature of block builder

The block ID (thor.Bytes32) can be computed as:

$BlkID = h \circ (hash(\Gamma - sig )[4:]$

where $h$ is the block number stored as a uint32 and $[4:]$ the operation that discards the first four bytes.