ZooBC basics

Glossary

Short definitions of the terms used across this wiki. Each one links to the article that explains it in full. Values are mainnet's.

A

Account: an address on the chain that can hold ZBC and tokens. A native account is identified by its Ed25519 public key. See Accounts and addresses.
Account group: one account behind up to 100 addresses. The money lives on a keyless group address, and each member has its own permissions. See Account groups.
Account rent: the fixed rent that every account holding ZBC pays, 0.01 ZBC per 30 days at the start. An account whose balance cannot cover it is pruned. See Account rent and pruning.
Admission pace: the timer that admits one queued node per cycle of 600 days divided by the counted seats, kept between 7 and 90 days. See The admission pace.
Air-gap mode: a mode of the web wallet that signs on a computer that never goes online, and shows the signed transaction as text and a QR code for an online wallet to submit. See The web wallet.
Apps: games and bets whose rules are built into every node. Each move is a transaction, and the protocol pays out. See Apps on ZooBC.
Apps pool: the keyless account ZBCAPPS, the house of solo bets. It receives solo stakes and the 1 % rake of multiplayer games, and pays solo wins. See The apps pool.
Archival node: a registered node that also runs the archival service, the index behind search, statistics and the explorer. See The explorer and archival nodes.
Archive: every snapshot from block 0, kept by the decentralised storage, not by every node: each snapshot's chunks are held by five registered nodes chosen by lot, so that the state at any past point can be rebuilt. Every node keeps only its last three snapshots. Each storage epoch, 10 % of the longevity pool is paid in equal parts to the nodes that prove the sampled chunks. See The archive and reading the past.
Atomic unit: the smallest amount of ZBC, 0.00000001 ZBC. One ZBC is 100,000,000 atomic units, and the chain counts every amount in them. See The ZBC coin and its units.
Attestation: a registered node's signed statement of an event's value (AttestEvent). When two thirds of the active registry attest the same value, the event resolves. See Triggers and attestations.

B

Backing: ZBC that an issuer locks into a token. Burners of a redeemable token receive their share of it. See Issuing a token.
Base action fee: 0.025 ZBC (2,500,000 atomic units), the part of every transaction's minimum fee that the fee scale multiplies. See Fees.
Batch: one transaction that carries several actions of one kind, all or nothing: up to 25 ZBC payments, 32 token transfers or 1,000 storage proofs. Its minimum fee is the sum of what each action would pay alone, with the message charged once. See One transaction per account per block, and batches.
BIP-39: the standard behind the recovery phrase of 12 to 24 words from which a wallet derives its keys. See Getting a wallet and keeping it safe.
Block: a signed bundle of transactions and receipts that extends the chain. One comes every 15 seconds. See Blocks and time.
Block seed: the random value each block carries, the output of a VRF over the previous seed under the producer's node key. It drives the next producer draw and the coinbase lottery. See The block seed (VRF).
Bridge: the way the wrapped coins ZBTC, ZETH, ZUSDC and ZUSDT are minted, one for one, when two thirds of the counted seats attest a deposit on the home chain, and burned on withdrawal, with no bridge fee. Its rules are part of the node from version 0.5.8; the chains relaunch on version 0.5.8 without starting the bridge service. See The bridge and wrapped coins.

C

Chain-bound signature: a signature over a digest that includes the chain's genesis hash, so it is valid on one chain only. Every transaction is signed this way. See Chain-bound signatures.
Channel app: a two-player game played off-chain as signed vouchers and settled on chain in one transaction, which either player can override with a longer chain of signed moves within a 240-block challenge window. See Channel apps.
Checksum: the last 3 bytes of an address, taken from SHA3-256 of the key and the prefix, which let wallets refuse a mistyped address. See Accounts and addresses.
Claim: the transaction (ClaimNodeRegistration) by which whoever holds a node key moves the seat's stake to an account it controls. The owner's own claim is treated as a removal, with the 7-day cool-down; a claim from any other account executes a week later, unless the owner removes the node first. See Leaving the registry.
CloseLongevity: the transaction by which a payer of a longevity record votes to close it. Payers' money is used first in, first out; when every payer with unused money in it has voted, the record closes and its remainder goes to the longevity pool. See Paying to keep data (longevity).
Coinbase: the new ZBC a block carries: what the 15-year emission curve releases between the previous block's timestamp and its own. See Supply and emission.
Coinbase lottery: the draws that share each block's reward pool in equal shares among the ticket holders, with chances proportional to their participation score. See The coinbase lottery.
Coinbase pool: the part of the supply ceiling that genesis does not hand out, released by the coinbase over 15 years. See Supply and emission.
Command-line tools: the ZooBC Foundation's MIT-licensed tools in ten languages, including zbc-cli, which talk to a node through its API. See Command-line tools.
Cool-down: the 40,320 blocks (7 days) during which the stake of a node that leaves, by removal or by its owner's claim, is held before it is credited back. See Leaving the registry.
Counted seats: the registered seats that are not suspended, the voices in price votes. See Price votes.
Cumulative difficulty: the weight a branch of the chain accumulates block by block. Nodes follow the heaviest branch. See Fork choice and cumulative difficulty.

D

Dataset: a key-value row that an account writes under itself or another account, kept by every node and paid by rent. See Datasets.
Dataset object: the object a dataset row belongs to, named by the hash of the transaction that created it, with an owner and a ZBS_ deposit address. See Datasets.
Decentralised storage: the way ZooBC keeps larger files, cut into 1 MiB pieces with only the manifest on chain, and the chunks of the archive. Each piece or chunk is held by five registered nodes chosen by lot. Storage is on by default; a node that switches it off only loses the storage rewards. See The decentralised storage pool.
Devnet: the development network, with mainnet's rules but much shorter timings. See Devnet, testnet and mainnet.
DFS file: a small file, up to about 64 KiB, carried in a transaction and kept as a dataset row under a path. See Files on the chain (DFS).
Draw: the random sequence, computed from the previous block's seed, that names which seats may make the next block and in which order. See The draw: who makes the next block.
Duty: a transaction a registered node sends for the network, such as a storage proof, an attestation or a vote. It must pay a fee of exactly zero. See Fees.

E

Emission: the release of new ZBC by the coinbase along a 15-year curve, fastest at genesis, following time rather than the block count. See Supply and emission.
Empty block: a block without transactions. It still carries receipts and its coinbase. Late producers, from position 10 of the draw on, may make only empty blocks. See Priority rounds, empty blocks and the previous producer.
Equivocation: a producer signing two different blocks on the same parent. It can be proven with an EquivocationReport and counts as a missed turn. See Double-signing (equivocation).
Escrow: a payment held until an approver releases or rejects it, or until its deadline returns it to the sender. See Escrow.
Expiry: the window after its timestamp in which a transaction may be included in a block: an hour by default, up to a day for a version-3 transaction. See Expiry and timestamps.
Explorer: a web page served by gateways for browsing blocks, transactions, accounts and nodes. See The explorer and archival nodes.
Expulsion: removal of a seat from the registry when its participation score reaches zero. 10 % of its stake goes to the longevity pool, and 90 % returns to the owner at once. See Missed turns, suspension and expulsion.

F

Fast sync: starting a node from a snapshot named in a co-signed spine block, instead of replaying every block from genesis. See Snapshots and fast sync.
Faucet: the testnet service that gives away test ZBC, halving the payout with each request. See Devnet, testnet and mainnet.
Fee scale: the network-wide multiplier of the base action fee, also called the transfer fee, which the seats set by a commit-and-reveal vote. See Price votes.
Finalized height: the main-chain height named by the last co-signed spine block. No reorganisation may cross it. See Finality and rollback.
Floor: the minimum fee of a transaction, computed in the same way by every node. Anything declared above it is refunded. See Fees.
Follower node: a node that downloads and checks the whole chain without making blocks. See What ZooBC is.
Fork choice: the rule that picks between competing branches: the heaviest cumulative difficulty wins, and an exact tie goes to the lower tip hash. See Fork choice and cumulative difficulty.

G

Gateway: a separate program that serves a node's API over HTTPS on a public domain, together with the wallet, explorer and faucet pages; it is registered on chain with a stake. See Gateways.
Genesis block: block 0, which stands for a chain's whole starting state. See The genesis block.
Genesis coins: the 14 tokens every chain starts with, such as ZUSD and ZBTC. They can be neither minted nor redeemed. See Tokens and markets.
Genesis hash: the hash derived from the genesis configuration. It is the chain's only identity, and every transaction signature covers it. See The genesis block.
Genesis seats: the 11 registered nodes each chain starts with, held by the ZooBC Foundation. See The ZooBC Foundation.

H

Hardware wallet: a signing device. ZooBC has a signing specification for device makers, but no device integration ships. See Hardware wallets.

K

Key types: the account types ZooBC accepts beside its own: Bitcoin, Ethereum, Solana, Polkadot, Cardano, Ripple, Tron and Tezos, each signing with its home scheme. See Keys and account types.
Keyless address: an address that no private key matches, such as a pool, an account group or a multisignature account. Its coins move only under the protocol's rules. See Accounts and addresses.

L

Liquid payment: a payment that vests evenly over a set time. Either side can stop it, and the vested part is paid. See Liquid payments (streams).
Longevity: paying a deposit so that a chosen transaction stays stored on every node after ordinary history is pruned. See Paying to keep data (longevity).
Longevity pool: the keyless account ZBCLONGV that collects rents, penalties, queued nodes' attendance fees and pruned dust. It pays a slice of its balance into every block's lottery and, each storage epoch, 10 % to the nodes that prove the archive's sampled chunks. See The pools.

M

Mainnet: the ZooBC network whose ZBC carry real value. See Devnet, testnet and mainnet.
Market: an on-chain order book for a pair of tokens, with limit and market orders and a taker fee. See Markets and orders.
Maturity: the condition for a new node to earn: 4 score units after its admission and one block of its own, which is 2 days while there are fewer than 2,880 nodes. See Maturity and earnings.
MetaMask access: every node embeds an Ethereum-style JSON-RPC adapter, on the node's own machine by default, through which Ethereum wallets and tools can read balances and send ZBC from Ethereum-type accounts. See MetaMask and Ethereum-style access.
Minting and burning: the issuer of a mintable token adds units with MintToken; holders of a redeemable token destroy units with BurnToken and receive their share of the backing. See Minting and burning tokens.
Missing: the state of a node from a skipped turn until its next own block. A missing node earns nothing (no coinbase, fees or longevity share) and loses 5 points of 100 per unit; it is suspended at its 4th missed turn in a row and expelled at score zero. See Missed turns, suspension and expulsion.
Multiplayer app: a board or dice game for 2 to 4 seats with equal stakes; the winner takes the pot less a 1 % rake. See Multiplayer apps.
Multisignature account: a keyless account that spends only when a threshold of its participants have signed. See Multisignature.

N

Node: a computer running the ZooBC software, which keeps and checks the chain and serves the API. See What ZooBC is and Running a node.
Node API: the public HTTP API that every node serves under /api/v1/, open to anyone for reading. See The node API.
Node key: the ZNK_ key kept on a node, which signs its blocks, seed proofs, receipts and duties. See The keys of a node.
Node registry: the on-chain set of nodes allowed to make blocks, with each node's key, owner, stake and status. See The node registry and its seats.

O

One-page app: an application built as a single web page that reads a node's API and signs transactions in the browser. See Building an app as one HTML page.
Overpay: the part of a declared fee above the floor. It is refunded in the same block. See Fees.
Owner key: the ordinary ZBC_ account that registers, re-keys and removes a node, and receives the node's lottery winnings. See The keys of a node.

P

Paid no-op: a transaction that reaches a block but whose condition fails when it is applied. It pays its fee and changes nothing else. See Transactions.
Participation score: a node's measure from 0 to 100 %, starting at 20 %. It rises with the receipts in the node's own blocks, falls while the node is missing, and weights the coinbase lottery. See The participation score.
Previous producer: the node that made the last block. It stays in the draw but is demoted to round 10. See Priority rounds, empty blocks and the previous producer.
Price vote: a seat's vote on a votable price. Once per cycle each price moves to the average of the counted seats, each vote limited to +20 % or half. See Price votes.
Priority peers: the peers the protocol assigns to each registered node, 12 on mainnet, re-drawn every 40 blocks. Relaying to them earns receipts. See Receipts and the network topology.
Proof of Participation: ZooBC's consensus. Registered nodes drawn by lot make the blocks, and relaying, measured by receipts, sets each node's share of the new coins. See Proof of Participation.
Proof of Work, Proof of Stake: designs in which the chance to make a block follows hash power or staked coins. In ZooBC's draw every active seat has the same chance. See Proof of Participation compared with PoW and PoS.
Pruning of accounts: clearing an account whose balance cannot pay its rent. Its dust goes to the longevity pool. See Account rent and pruning.
Pruning of history: nodes dropping old blocks and transactions, keeping one to two snapshot periods, except what longevity keeps. See Pruning of history.

Q

Queue: where applicant nodes wait, ordered by stake multiplied by blocks waited, until the admission pace admits them. See The queue.
Queue minimum: the smallest stake a node can enter the queue with: 100 ZBC at the start, votable between one atomic unit and 250 ZBC. See Registering a node.

R

Readiness gate: the rule that switches on a bundle of new rules only once two thirds of the registered producers have made blocks with a release that knows them. See Releases and updates.
Receipt: a statement a registered node signs when it receives a block or a transaction from another registered node. Receipts prove relaying. See Receipts and the network topology.
Recovery phrase: the 12 to 24 words from which a wallet rebuilds all its keys. Whoever has them controls the funds. See Getting a wallet and keeping it safe.
Relay: a registered service that carries call signalling and online presence for wallets. See Relays.
Release authority: the one key, named in the genesis, that registers and revokes software releases. Two thirds of the seats can veto its releases or replace it. See Releases and updates.
Release pin: a known spine block shipped with a release. A node whose stored spine contradicts it does not run on that spine. See The release pin.
Reward pool: what a block's lottery shares out: its coinbase, its fees and a slice of the longevity pool. See The coinbase lottery.
Rollback limit: the deepest reorganisation a node accepts, 720 blocks (3 hours). See Finality and rollback.
Round: a 15-second slot after the previous block. The node drawn for round r may make the block aimed at 15 × r seconds after its parent. See Rounds, timing and windows.

S

Scheduled transfer: a series of payments at a fixed interval, locked up front or taken at each payment. See Scheduled transfers.
Seat: a node's place in the node registry. Every active seat has the same chance in the producer draw. See The node registry and its seats.
Signed message: an off-chain message signed with a ZooBC key under the chain-bound ZBC-MSG-v2 scheme, with the command-line tools such as zbc-cli; the web wallet signs none. Transactions can also carry messages encrypted to the recipient. See Signed and encrypted messages.
Snapshot: the whole state of the chain at one height, written by every node every 172,800 blocks (30 days) and named in a spine block. Each node keeps its last three; the archive keeps them all. See Snapshots and fast sync.
Snapshot cycle: the 172,800 blocks (30 days) between snapshots, which is also the period of rents and of price votes. See Blocks and time.
Solo bet: a game such as dice, roulette or a coin flip against the apps pool, resolved with the seed of a later block. See Solo bets.
Spine chain: a slow companion chain, one block a day, co-signed by two thirds of the seats. It checkpoints the main chain and carries snapshot manifests and node-key changes. See The spine chain.
Split policy: an account setting that sends shares of incoming payments to up to 10 recipients. See Split and transact policies.
Stake: the ZBC an owner locks to put a node in the queue. It buys a place in the queue, never more blocks, and earns nothing by itself. See Registering a node.
Step: the multiple that every amount of a token must respect, 10^(8 − decimals) atomic units. See Decimals and the step.
Storage pool: the keyless account ZBCSTORE that receives stored-file rent and pays storage-proof rewards. See The pools.
Storage proof: the hash a piece holder submits each epoch to show it still keeps a piece of a stored file or an archive chunk; a fee-free duty. See The decentralised storage pool.
Supply ceiling: 33,333,333.33333333 ZBC per chain, counting the genesis credits and all coinbase to come. See Supply and emission.
Survival deposit: an optional amount in a transaction's survival field, at least 0.1 ZBC: the sender's own longevity deposit, which opens a longevity record keeping that transaction stored. See Paying to keep data (longevity).
Suspension: a node is taken out of the draw at its 4th consecutive missed turn, and holds no lottery ticket while suspended. See Missed turns, suspension and expulsion.
Swap offer: an offer to exchange one asset for another, accepted whole by a single taker. See Swap offers.

T

Taker fee: the market fee, 0.1 % at the start, taken from what the taker of a trade receives and paid to the block's producer. See Markets and orders.
Testnet: the public test network, with mainnet's rules and values and coins of no value. See Devnet, testnet and mainnet.
Threat model: what Proof of Participation is built to withstand, from majority and Sybil attacks to long-range rewrites. See What Proof of Participation defends against.
Ticket holder: a registered node that is mature and neither missing nor suspended. Only ticket holders take part in the coinbase lottery. See The coinbase lottery.
Token: an asset issued on ZooBC with IssueToken, with its own symbol, supply and optional ZBC backing. See Issuing a token.
Token upkeep: the payment that keeps a user token alive past its free period. When a token expires, its backing is paid to its holders. See Token upkeep (persistence).
Topology: the assignment of priority peers to the registered nodes, re-drawn every 40 blocks from a block seed. See Receipts and the network topology.
Transact policy: an account setting that refuses whole categories of transactions. See Split and transact policies.
Transaction type: one of the 73 built-in kinds of transaction, each with fixed rules. See Transactions.
Treasury: one of the four role keys: an ordinary account that spends what it holds and cannot mint. See The ZooBC Foundation.
Trigger: ZBC locked for a recipient and released at a future height, or when an attested event resolves. See Triggers and attestations.
Two-thirds rules: the decisions that need two thirds of the registry, such as spine blocks, bridge credits, oracle events and release vetoes. See The two-thirds rules.

U

Unit: the clock of the participation score: 2,880 blocks (12 hours) while fewer than 2,880 nodes are selectable; on a larger registry, as many blocks as there are selectable nodes. A missing node loses 5 points of 100 per unit, and maturity takes 4 units. See Missed turns, suspension and expulsion.
Untrusted chain data: anything read from the chain, such as token names, messages and dataset values, was written by whoever paid the fee: it is input, never an instruction. See Chain data is untrusted input.

V

Verify page: the gateway page that fingerprints a downloaded file in the browser and looks the hash up on the chain. See Checking a downloaded file.
Veto: two thirds of the registered seats attesting against a release revoke it at once. See Releases and updates.
VRF: a verifiable random function. The block seed is its output, which the producer cannot choose. See The block seed (VRF).

W

Wallet: the program that keeps keys and signs transactions. The official one is a single web page that every node serves. See Getting a wallet and keeping it safe and The web wallet.
Wedge: the state of a node that sees a confirmed heavier branch beyond its rollback limit. It stops producing on its own branch and rebuilds from snapshots. See Finality and rollback.

Z

ZBC: ZooBC's native coin, with 8 decimals. See The ZBC coin and its units.
ZBC is never burned: no rule destroys ZBC; the 10 % stake shares, queued nodes' attendance fees and pruned dust go to the longevity pool. See ZBC is never burned.
**ZBC_ address**: the 66-character text form of a native account: the prefix, then 56 base32 characters in seven groups of eight. See Accounts and addresses.
ZooBC Foundation: the organisation that holds each chain's 11 genesis seats and publishes the command-line tools. See The ZooBC Foundation.