A full blockchain in Go;

• Nakamoto consensus.
  • Hashcash.
  • Dynamic difficulty retargeting (epochs).
  • Proof-of-work consensus - longest/heaviest chain rule.
  • Merklized transaction tree for light client availability.
• State sync - interactive binary search for common ancestor, parallelised block header download from multiple peers.
• Ethereum-like coin state machine - basic ERC20 transfers.
• ECDSA (curve P256) wallets for signing transactions. Signature malleability fixes.
• Core data structures: RawBlock, RawTx, Block, Tx, Epoch, BlockDAG, current tip, Miner, NetPeer, Node
• Networking: HTTP peer interface, messages/methods include [bootstrap/gossip peers, gossip blocks, gossip txs].
• Miner: mine new blocks on the tip, measure hashrate.
• CLI: start a node, connect to the network, mine blocks.

Simplifications of the design:

• The difficulty target is represented as [32]bytes; it is uncompressed. There is no nBits or custom mantissa.
• Transaction signatures are in their uncompressed ECDSA form. They are [65]bytes, which includes the ECDSA signature type of 0x4.
• Transactions specify from and to in terms of raw ECDSA public keys. There is no ECDSA signature recovery to guess the pubkey from a signature.
• The state machine is an account-based model, not a UXTO model. It implements just a transfer for coins.

Dependencies:

• go-sqlite3

Couple philosophies of this project:

• distilling a blockchain network down to its core primitives at all layers of the stack.
• building the equivalent of sqlite for blockchains. Reliable, portable primitives.

Progress.

WIP.

Install.

Make sure you have Go 1.2.3+ installed.

make && cd build/ && ./tinychain node --port 8121 --db testnet.db