Methods and systems for managing and/or processing a blockchain to maintain data security for confidential and/or personal data are provided. According to certain aspects, the disclosed data security techniques may enable access sharing functionality utilizing the blockchain. For example, access sharing may be utilized to share policy information. The policy information may be associated with a smart contract. Accordingly, the policy information may be encrypted using a public key for the smart contract and compiled into a block of the blockchain. In response to a request to provide access to the information to a particular node, the private key for the smart contract may be encrypted using the public key for the particular node and compiled into a block of the blockchain.