Distributed storage system and method for transmitting storage-related messages between host computers in a distributed storage system uses a handshake operation of a first-type communication connection between a source data transport daemon of a source host computer and a target data transport daemon of a target host computer to derive a symmetric key at each of the source and target data transport daemons. The two symmetric keys are sent to a source data transport manager of the source host computer and to a target data transport manager of the target host computer. The source and target data transport managers then use the same symmetric keys to encrypt and decrypt storage-related messages that are transmitted from the source data transport manager to the target data transport manager through multiple second-type communication connections between the source and target data transport managers.