Managing blockchain access

Techniques are described for managing access to data stored in a blockchain, and for managing the communication of blockchain data to other entities. A private key may be generated and issued to an external entity to enable the external entity to access an internal (e.g., private blockchain). The external entity may be an external (e.g., public) blockchain, device, process, or user that is outside an internal network. The key may be associated with metadata that includes constraints, conditions, or rules governing access to the blockchain. An authorized entity may employ the key to request access to the blockchain via access management module(s), and the access management module(s) may employ the metadata to determine whether to approve the request. The access management module(s) may also employ rules governing outbound communication of data from internal blockchain(s) to external entities.