Abstract: A method of rescinding access to blockchain data may include the addition of metadata to an entire blockchain or to component blocks in a blockchain which contain the encrypted keys for each owner or otherwise authorized party. Said metadata may be added when a block is created, including metadata to store state and communicate information. After a blockchain is published, an authorized party may request rescission of access to one or more blocks or the entire blockchain by appending one or more instruction blocks to the chain. The other parties authorized to access this block or blockchain may agree to said request. If a sufficient number of parties have agreed to rescind, the removal of access keys may be publicly confirmed with the result that the original data held within the block or blockchain can no longer be decrypted.