A full blockchain in Go;

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

Make sure you have Go 1.2.3+ installed.

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

Work breakdown:

• building a simple block
• hashing a simple block
• building a proof of work solution
• building a chain of blocks
• computing the epoch/difficulty window for a chain of blocks
• creating a merkle tree accumulation of transactions
• computing the cumulative work in a chain of blocks
• constructing a blockdag and then choosing a tip
• improve txs
  • replay protection for txs, tx nonce
  • add version to RawBlock, RawTransaction for future prosperity
• block sync algorithm between nodes
• simple coin state machine
  • coinbase
  • state snapshots
  • state diffs
  • state checkpoints
• build a simple mempool module
• adding a simple state machine
  • ValidateBlock
    • first transaction is the coinbase
    • maintain a uxto set - unspent transaction outputs
    • validate txs - validate signature, transfer the coins
• adding a method to recompute the state machine and using cached state
• implementing networking
  • simple wrapper for sockets - address, port, and hof's to wrap the latency delays dropped packets etc
  • peers connect
  • peers can send messages, peers can register message handlers
• implement simple peer
  • can send and receive blocks via network
  • gossip block, gossip tx, get blocks, sync tip
• implement peer discovery and bootstrapping
• implement wallet and cli tool
• implement miner process
• implement admin api
• finally implement the CLI tool
  • start miner
  • stop miner
  • check balance
  • check network online nodes
  • send coins
  • receive coins
• add nonce to tx
• refactor miner code to be pretty
• improve robustness of sql queries- need to verify we use right number of columns and ?'s
• improve block/rawblock. missing fields, unset fields etc. tests for this.
• double check big endian canonical encoding