syntax = "proto3"; message CEPIdentification { string peer_id = 1; string public_key = 2; string nonce = 3; string timestamp = 4; string version = 5; } message CEPResponse { string peer_id = 1; string public_key = 2; string signed_nonce = 3; } message CepMessage { oneof cep_type { CEPIdentification identification = 1; CEPResponse response = 2; } }