A consent block is a type of block that may be stored in a blockchain. Each consent block has an owner and may store an owner consent contract, i.e., a smart contract containing owner-specified access rules that determine who may access data assets that are stored in other blocks of the blockchain and owned by the same owner. The consent block may alternatively store a global consent contract containing global access rules that supersede owner-specified access rules. The consent block also stores a hash value determined from the consent contract and a previous hash value of the block immediately preceding the consent block. The consent contract and the position of the consent block in the blockchain are verifiable from the hash value. Each consent block, once added to the blockchain, becomes part of the immutable record of data stored in the blockchain, and therefore leaves an auditable trail.