Systems, methods, and non-transitory computer-readable storage media for a non-replayable communication system are disclosed. A first device associated with a first user may have a public identity key and a corresponding private identity. The first device may register the first user with an authenticator by posting the public identity key to the authenticator. The first device may perform a key exchange with a second device associated with a second user, whereby the public identity key and a public session key are transmitted to the second device. During a communication session, the second device may transmit to the first device messages encrypted with the public identity key and/or the public session key. The first device can decrypt the messages with the private identity key and the private session key. The session keys may expire during or upon completion of the communication session.