1️⃣-Message Format

Overview

All messages sent between nodes have headers. The initial handshake messages are sent unencrypted, and all other messages are encrypted and authenticated using the keys that are generated during the initial handshake.

All messages payloads are serialized using Protocol Buffers.

Protocol buffers are a language-neutral, platform-neutral, extensible mechanism for serializing structured data. You can find documentation on the Google Developers site.

To develop with protocol buffers you will need to install the protocol buffer compiler (to compile .proto files) and the protocol buffer runtime for your chosen programming language.

Protocol buffers currently support development in Java, Python, Go, Rust, C, C++, Objective-C, C#, Dart, Ruby, Perl, Haskell, Javascript, and more.

The unencrypted message

Size (bytes)	Name	Data Type	Description
4	magic	uint32	Magic value to specify the message's network
4	length	uint32	Payload length
4	type	uint32	Message type
4	checksum	uint32	First 4 bytes of sha256 hash of JSON-serialized message
length	payload	bytes	The actual data

Magic values

Network	Magic value
mainnet	0xd9b4bef9
testnet	0x0709110b
simnet	0x12141c16
regnet	0xdab5bffa

The encrypted message

Size (bytes)	Name	Data Type	Description
4	length	uint32	Length of the payload
length	ciphertext	bytes	The encrypted data

Ciphertext pre-encryption format

Size (bytes)	Name	Data Type	Description
4	length	uint32	Payload length
4	type	uint32	Message type
length	payload	bytes	The actual data