xicochain

wip

Network architecture

The diagram below shows the architecture behind the network layer (src/network.rs): peers discover each other via mDNS, connect over TCP with Noise encryption, and exchange blocks and transactions through gossipsub.

        +---------------------+                     +---------------------+
        |       Node A        |                     |       Node B        |
        |     12D3…KEEQ       |                     |     12D3…mkP2       |
        |     tcp/39665       |                     |     tcp/37379       |
        +----------+----------+                     +----------+----------+
                |                                           |
                | <-------- 1. mDNS discovery ------------> |
                |                                           |
                | -------- 2. TCP + Noise handshake ------> |
                |                                           |
                | <-------- 3. gossipsub GRAFT -----------> |
                |                                           |
                | ================ mesh formed ============ |
                |                                           |
                | -------- 4. publish --------------------> |
                |            (blocks/1, txs/1)              |
                |                                           |

Types

xicochain uses the UTXO model (src/types.rs), Bitcoin-style: transactions consume previous outputs and create new ones. The fee is implicit, the gap between input and output sums, set by the sender, collected by the miner.

Block
├── BlockHeader
│   ├── previous_block_hash   [u8; 32]   link to parent block
│   ├── merkle_root           [u8; 32]   commits to all transactions
│   ├── timestamp             u64        unix seconds
│   ├── difficulty            u32        required leading zero bits
│   └── nonce                 u64        PoW search variable
└── transactions: Vec<Transaction>
    ├── inputs:  Vec<TxInput>            outputs being spent
    │   ├── previous: OutPoint           (txid, index) of the output
    │   ├── signature                    proof of ownership
    │   └── pubkey
    └── outputs: Vec<TxOutput>           new coins created
        ├── amount: u64
        └── recipient

Departures from Bitcoin: u64 timestamps and nonces, plain leading-zero-bits difficulty instead of nBits, single SHA-256 instead of double.