In legacy enterprise applications of cross-institution transactions, all institutions maintain their own ledgers. The discrepancies between different ledgers result in disputes and increase the need for manual reconciliations with settlement times and intermediaries with associated overhead costs. However, a blockchain implementing a distributed ledger, where transactions must be validated by consensus and cannot be altered once written to the ledger, guarantees the consistency of multi-institutional data and removes manual reconciliations and intermediaries. Blockchain is a decentralized, tamper-proof, traceable, trustless distributed database managed by multiple participants. An enterprise blockchain satisfying enterprise application requests means that any node must be authorized and authenticated in order to join the network. This paper presents an architecture model of enterprise blockchains based on the three mainstream blockchain platforms:Hyperledger Fabric, Corda, and Quorum. Furthermore, the principles and technologies of enterprise blockchains according to transaction flow, P2P network, consensus mechanism, blockchain data, smart contract, and privacy are discussed. Finally, by analyzing the limitations of the existing technologies, some challenging research issues and technology trends of enterprise blockchains are summarized.