Message structure (Protocolbuffers)

Creating a network of TrustChain peers which only run a Java version of TrustChain is not very useful. Therefore the TrustChain blocks and messages should be compatible with many platforms, so cross-platform connection is possible. For the storage of the chain this is achieved by using SQLite, which has implementation for many platforms. For sending messages (blocks and crawlrequests) this compatibility can be achieved by using Google’s Protocolbuffers, which is a cross-platform data serialization mechanism. When implementations across platforms use the same Protocolbuffers setup, messaging will across these platforms will be possible.

Making changes

Protocolbuffers is used to create the structure of messages. This includes all the messages used by the network overlay (Connection between peers) and the structures of the Trustchain related objects like TrustChainBlock and CrawlRequest. A complete overview of the message structure can be found in Complete structure. With Protocolbuffers the corresponding Java classes can be compiled, so it is possible to call the structures as objects. Making changes and recompiling the Java classes is quite easy, just follow the tutorial of ProtocolBuffers and you should be fine. When making changes, don’t forget to also update the database structure if necessary.

Complete structure

The complete structure of all parsable objects as defined in protocolbuffers.


  • bytes source_public_key
  • string source_name
  • bytes destination_address
  • int32 destination_port
  • int32 type
  • Payload payload


  • IntroductionRequest introductionRequest
  • IntroductionResponse introductionResponse
  • Puncture puncture
  • PunctureRequest punctureRequest
  • TrustChainBlock block
  • CrawlRequest crawlRequest


  • bytes public_key
  • int32 sequence_number
  • bytes link_public_key
  • int32 link_sequence_number
  • bytes previous_hash
  • bytes signature
  • Transaction transaction
  • google.protobuf.Timestamp insert_time


  • bytes unformatted
  • string format
  • Claim claim


  • bytes name
  • google.protobuf.Timestamp timestamp
  • int32 validity_term
  • bytes proof_format


  • bytes public_key
  • int32 requested_sequence_number
  • int32 limit


  • int64 connection_type


  • int64 connection_type
  • string internal_source_socket
  • Peer invitee
  • repeated Peer peers


  • string sourceSocket


  • string source_socket
  • Peer puncture_peer


  • bytes address
  • int32 port
  • bytes public_key
  • string name
  • int32 connectionType