In MultiChain, block creators must prove their identity by signing blocks
Block signatures are embedded inside the
OP_RETURN metadata of the coinbase transaction, using a regular bitcoin-style signature format. The payload signed by the block creator is the full block header, with the following modifications:
merkle_rootis recalculated based on the txid of the coinbase transaction with the
OP_RETURNremoved. This prevents a dependency loop from block signature → coinbase txid → merkle root → block header → block signature.
noncefield is set to
0. This avoids having to recalculate the signature for every attempt at finding a block hash to match the target difficulty. However it does lead to some malleability in that a user without
minepermissions could generate a block with the same content as a valid block, but with a different
nonce. Seeing as the
nonceserves no purpose other than to randomize the block’s content for its hash, this should not be a source of concern.