The present application discloses methods and systems to receive a data storage instruction including data to be stored and an identifier of the data; identify a blockchain corresponding to the identifier, the blockchain stored on blockchain network storage nodes of a data access system; identify a key pair corresponding to the identifier, the key pair comprising a private key and a public key; encrypting the data based on the public key to provide encrypted data; updating the blockchain by storing the encrypted data in the blockchain; and storing the updated blockchain in a particular blockchain network storage node of the blockchain network storage nodes, the particular blockchain network storage node associated with a data storage device.