blockchainkit 0.3.0

Added

• blockchainkit.contracts, a sixth subpackage on designing, breaking and
  verifying smart contracts, with a history page of 17 breakthroughs, each
  with its own gallery example, from Floyd and Hoare (1967-1969) to
  Beanstalk's flash-loan governance attack (2022), and an exercise page.
  New APIs: the world-state model World and Contract (call,
  delegatecall, send, CREATE and CREATE2, events, selfdestruct, gas,
  per-call rollback, invariants) with create_address and
  create2_address; weakest_precondition, check_triple and
  run_program; symbolic_execute, symbolic_bytecode (for vm
  programs) and solve; requires and ensures; fuzz and shrink;
  Ricardian contracts; Mint and Purse; ERC-20 and ERC-721 tokens; King
  of the Ether, GovernMental, block-hash and commit-reveal lotteries; the
  Parity wallet libraries; naive and EIP-1967 proxies; a CREATE2 factory;
  and flash-loan governance. Plots: plot_call_tree,
  plot_symbolic_paths and plot_storage.
• blockchainkit.economics, a seventh subpackage on incentives, fees and
  markets, with a history page of 16 breakthroughs, each with its own
  gallery example, from Schelling's focal points (1960) to proposer-builder
  separation (2022), and an exercise page. New APIs: coordination_probability
  and schelling_round; first- and second-price auctions, virtual values,
  equilibrium bids and expected revenue; the logarithmic market scoring
  rule; block_subsidy, issued_supply and double_spend_incentive;
  simulate_block_rewards, mining_gap and undercutting_payoffs;
  optimal_mining_revenue and honest_mining_is_equilibrium;
  next_base_fee and simulate_fee_market; amount_out,
  impermanent_loss and the ConstantProductPool contract; Dai's
  VaultEngine with Stablecoin and PriceFeed; the OracleLender and
  OracleAttacker contracts; priority_gas_auction, sandwich_profit and
  sandwich_attack; and simulate_pbs. Plots: plot_fee_market,
  plot_constant_product and plot_gas_auction. The model boundaries page
  gains an "Economic models" section.
• blockchainkit.channels, an eighth subpackage on layer-2 scaling and
  interoperability, with a history page of 16 breakthroughs, each with its
  own gallery example, from Reed-Solomon codes (1960) to the Ronin and
  Wormhole bridge exploits (2022), and an exercise page. New APIs:
  rs_encode, rs_recover and rs_decode (Berlekamp-Welch);
  SpilmanChannel, DuplexChannel with invalidation_locktimes,
  LightningChannel (revocation keys, shachain secrets, penalties),
  EltooChannel, and the StateChannel and PreimageManager contracts,
  all with Script outputs checked by vm.verify_script; Watchtower,
  make_appointment and PISA's tower_liable; ChannelNetwork for
  multi-hop HTLC routing and probe_balance; AtomicSwap; the BTCRelay
  contract and mine_header; ValidatorBridge, GuardianVerifier and
  WormholeBridge; PlasmaChain with Plasma Cash exits;
  shard_failure_probability and atomix_transfer; ZKRollup,
  OptimisticRollup and bisect; and extend, simulate_sampling and
  encoding fraud proofs for data availability. Plots: plot_shares,
  plot_route and plot_detection. The model boundaries page gains a
  "Channels, rollups and bridges" section.
• blockchainkit.proofs, a ninth subpackage on zero-knowledge and succinct
  proof systems, with a history page of 16 breakthroughs, each with its own
  gallery example, from the Schwartz-Zippel lemma (1980) to Halo (2019),
  and an exercise page. New APIs: polynomial arithmetic, interpolation and
  the FFT over the BabyBear field (FIELD_PRIME) and a Fiat-Shamir
  Transcript; identity_test; sumcheck and multilinear_extension;
  tqbf_protocol; hadamard_proof and pcp_verify; kilian_argument,
  micali_proof and verify_cs_proof; a toy supersingular
  PAIRING_CURVE with the Tate pairing; KZG (trusted_setup,
  kzg_commit, kzg_open, kzg_verify, forge_opening); powers-of-tau
  ceremonies (contribute, verify_contribution); the R1CS builder
  Circuit, r1cs_to_qap and qap_divide; Groth16; MiMC and a Zerocash
  ShieldedPool with prove_spend; PlonkCircuit and PLONK with
  permutation_product; Bulletproofs range_proof; fri_prove and
  fri_verify; a Fibonacci stark_prove; and Halo's ipa_open,
  ipa_defer, accumulate and decide. Plots: plot_field_polynomials,
  plot_proof_sizes and plot_copy_constraints. The model boundaries page
  gains a "Proof systems" section, and blockchainkit.constants the
  TRANSCRIPT_DOMAIN, IPA_GENERATOR_DOMAIN and MIMC_DOMAIN tags.
• blockchainkit.fraud, a tenth subpackage on financial fraud on and
  around blockchains, with a history page of 17 breakthroughs, each with its
  own gallery example, from Ponzi's scheme (1920) to address poisoning
  (2022-2023), and an exercise page. New APIs: simulate_ponzi,
  breakeven_growth, simulate_lending_ponzi and referral_commissions;
  the ChainPonzi contract with value_flows and ponzi_features;
  benford_test; the MerkleSumTree with verify_sum_proof,
  liability_tree, audit and reserve_ratio; Provisions-style proofs of
  solvency (SolvencyProver, verify_solvency, OR proofs and bitwise
  range proofs over Pedersen commitments); reissue_missing and the
  Custodian contract; verify_source and effective_code; the
  TokenSale (DAICO) contract; seven Torres et al. honeypot contracts with
  explorer_view; SellBlockToken, HiddenMintToken and sell_test;
  simulate_bot_market, return_by_activity, simulate_pump_and_dump
  and detect_pumps; find_wash_trades and simulate_nft_market; the
  Drainer contract with open_approvals and allowance_exposure; and
  grind_lookalike and poisoning_suspects. Plots: plot_ponzi,
  plot_benford and plot_price_spikes. The model boundaries page gains
  a "Fraud models" section, and blockchainkit.constants the
  SUM_LEAF_DOMAIN, SUM_NODE_DOMAIN, SOLVENCY_DOMAIN and
  LOOKALIKE_DOMAIN tags.
• blockchainkit.privacy, an eleventh subpackage on anonymity and
  confidentiality on public ledgers, with a history page of 15
  breakthroughs, each with its own gallery example, from Chaum's mix-nets
  (1981) to Tornado Cash (2019), and an exercise page. New APIs: MixNode,
  seal, wrap and mix_cascade; circuit_compromise_rate,
  simulate_flows and match_flows; k_anonymity, equivalence_classes
  and effective_anonymity_set; ring_sign and ring_verify;
  lsag_sign, mlsag_sign, key_image and linked; simulate_payments,
  cluster_addresses and score_clusters; stealth_keys,
  stealth_payment, owns_output and one_time_secret; coinjoin and
  link_change; the RSA accumulator, ZerocoinPool and
  prove_zerocoin_spend; ring-signature range proofs and
  verify_confidential; ringct_spend and verify_ringct;
  mimblewimble_transaction, aggregate and cut_through; the TumbleBit
  Tumbler with run_tumbler; simulate_rings, chain_reaction and
  trace_rings; and the Mixer contract with prove_withdrawal and
  mixer_report, proving with the Zerocash circuit of proofs. Plots:
  plot_cluster_sizes, plot_ring_positions and plot_anonymity_sets.
  The model boundaries page gains a "Privacy models" section, and
  blockchainkit.constants the MIX_DOMAIN, RING_DOMAIN,
  KEY_IMAGE_DOMAIN, STEALTH_DOMAIN, KERNEL_DOMAIN,
  ACCUMULATOR_DOMAIN and TUMBLER_DOMAIN tags.
• blockchainkit.wallets, a twelfth subpackage on keys as users actually
  hold them, with a history page of 15 breakthroughs, each with its own
  gallery example, from BCH codes (1959-1960) to ERC-4337 account
  abstraction (2021), and an exercise page. New APIs: BCHCode and
  minimal_polynomial; verhoeff_digit, luhn_digit and
  detection_rates; pbkdf2 and crack_pin; scrypt, salsa20_8,
  block_mix and romix with a memory-time trade-off; Base58Check,
  p2pkh_address and is_valid_address; bech32_encode,
  bech32_decode, segwit_encode, segwit_decode and p2wpkh_address
  for Bech32 and Bech32m; serialize_script, multisig_redeem_script
  and verify_p2sh; BIP32's master_key, derive_private,
  derive_public, serialize_extended_key and recover_parent_private;
  BIP39's entropy_to_mnemonic and mnemonic_to_seed; BIP44's
  derive_path and discover_accounts; brain_wallet_key and
  simulate_brain_drain; ecdsa_sign and ecdsa_verify;
  threshold_keygen and threshold_sign; the SocialRecoveryWallet
  contract with recovery_risk; and ERC-4337's EntryPoint,
  SmartAccount and bundle. Utilities: RIPEMD-160 and hash160,
  compressed secp256k1 keys, and GF(2**m). Plots:
  plot_detection_rates, plot_memory_tradeoff and plot_recovery_risk.
  The model boundaries page gains a "Wallet models" section, and
  blockchainkit.constants the HARDENED_OFFSET, BIP32_SEED_KEY,
  BIP39_SALT_PREFIX, MAX_SCRIPT_ELEMENT_SIZE and
  USER_OPERATION_DOMAIN constants.
• World.fork() in blockchainkit.contracts: an independent copy of the
  world state on which to try transactions, as a wallet simulates one
  before sending it.
• Domain tags for contract addresses, block hashes, Ricardian contracts,
  lottery commitments and wallet approvals in blockchainkit.constants,
  and for channel states, Plasma transfers, rollup state, bridge
  withdrawals and watchtower appointments,
  and a "Contract world model" section in the model boundaries page.

Fixed

• consensus.systems.fork_choice imports structures only for type
  checking, so a subpackage that loads structures before consensus no
  longer hits a circular import.
• FinalityGadget no longer depends on vote arrival order: justification and
  finality are recomputed over every recorded vote, so a supermajority link
  recorded before its source was justified now counts once it is.
• spread_rumor validates source before using it, raising ValueError
  rather than IndexError for a peer outside the graph.
• BloomFilter.false_positive_rate and BloomFilter.optimal_hash_count
  validate their arguments (optimal_hash_count(m, 0) raised
  ZeroDivisionError).
• The GHOST history, module docstring and example no longer claim that
  Ethereum's proof-of-work chain used GHOST for fork choice: it adopted uncle
  rewards but kept heaviest-chain selection.

Changed

• History pages follow mathematicskit's entry form: an epigraph per page, and
  per entry one prose account with its formula, an Implementation: line that
  also states the teaching-vs-production difference, References:, and the
  gallery link. The "In plain language", "Reading the experiment" and
  "Experiment" blocks, the admonitions and the in-entry doctests are folded
  in or removed. The history index is reduced to its overview.
• The history pages of crypto, consensus, network, vm, contracts,
  economics, channels, proofs and fraud are rewritten for readers new
  to the field: each introduction and entry opens with the problem the
  breakthrough solved, defines its terms in plain language, and spells out
  algorithms as numbered steps.
• The documentation's landing page is titled "Learn How Blockchains Work in
  Python" and links the sibling toolkits.
• Gallery examples follow mathematicskit's layout: raw docstrings without
  section headings or trailing links, one import cell, and plt.show(). The
  Merkle-proof example's exercise moved to the end, and the capstone is now
  structures/chain/plot_01_payment_lifecycle.py.
• subtree_work and ghost_tip compute every subtree's work in one pass.