Terms, defined

36 of 36 terms

Batch

A group of L2 transactions executed together and published as a unit. Batching is what makes settlement cost per transaction small.

Bond

Value staked behind a claim — a proposed root, a challenge — forfeited if the claim proves false. Bonds convert honesty from a virtue into the cheaper strategy.

Censorship resistance

The property that no operator can permanently prevent your transaction from landing. On Solieum this is forced inclusion: a route through Solana the sequencer cannot close.

Chain ID

The convenience number tooling asks for. solieum-testnet-gamma, the devnet chain since 2026-09-11, is 7790; the beta chain it succeeded is 7789 and the first, alpha, is 7788; the Solieum coin chains are 9232, anchored to devnet with its own programs, and 9233, on an embedded Layer 1. Mainnet is reserved as 2222 and the production devnet as 6666; neither has launched; nothing is secured by the number — two chains can share it and still differ in genesis, and it is the genesis hash that is the identity.

Challenge window

The period during which a committed state root can be disputed. Withdrawals do not complete until it closes. Its length is a security parameter, not a performance one. Forty-eight hours on Solieum, defined as wall-clock time — 172,800 seconds — since ADR-0016 was amended on 22 September 2026, because Solana's slot time fell and the 432,000 slots it was stored as no longer meant 48 hours; that slot count stays as the dispute game's on-chain budget (ADR-0016, replacing the seven days of ADR-0003). The per-move dispute deadlines still count slots, so a halted chain cannot time out whoever owed the next move; the window itself now counts wall-clock time, so an outage spends hours nobody could challenge in — an accepted cost, weighed against slot-time drift that had turned 48 hours into 20 on devnet. Enforced by the settlement program; a one-shot administrative migration moves a running chain from slots to seconds — done on the gamma devnet chain on 22 September 2026, roots 1 to 292 keeping the slot rule and root 293 onward counting seconds, and on the coin chain 9232 the same day (slot 502,262,063; roots 1 to 12 keep the slot rule, 13 onward count seconds). The beta chain (2026-09-05) carried the 48 hours, and the alpha chain it replaced kept its seven days. It answers one question only, whether this root was challenged, and that is arithmetic in hours; the separate 24-hour air gap (ADR-0015) covers whether the dispute machinery itself was sound. Quote the total exit, window plus air gap, never the window alone.

Custody

Who can move funds without you. If any party can — a multisig, an upgrade key — the funds are in that party's custody, whatever the interface implies.

Data availability

The guarantee that the data needed to reconstruct and verify L2 state is published where anyone can get it. Without it, proofs and exits are both impossible. On Solieum the data is published in Solana transactions through the data-availability program.

Derivation

Reconstructing the L2's state purely from published data. If derivation is possible for anyone, the operator is checkable; if not, the operator is trusted.

Devnet

Solana's public test cluster, where Solieum's programs are deployed today — five for each of the three rollup chains — the frozen alpha one, the beta one and the gamma one that succeeded it — plus a single sequencer bond program those chains share, and, since 21 September 2026, the settlement, data-availability and inbox programs of Solieum's first coin chain, which anchors there without a bridge portal. The rollup chains share the bond program safely because a bond account is keyed to the sequencer's own key and no two chains use the same one. The node settles real blocks to all of it. SOL there has no monetary value, and neither does the SULI on the coin chain.

Escape hatch

Withdrawing by proving ownership against the last final state root, with no cooperation from the operator. The property that distinguishes a Layer 2 from a custodian.

Finality

The point at which a result cannot be reversed. On an optimistic Layer 2 that is the end of the challenge window — not the sequencer's confirmation, which is revocable.

Forced inclusion

Submitting a transaction through Solana so the sequencer cannot censor it indefinitely.

Fraud proof

A demonstration that a committed state root is wrong. Interactive versions narrow the dispute to a single instruction the base layer can check cheaply.

Genesis hash

The canonical hash of the genesis file, and the chain's real identity — the numeric chain id is a convenience. Transactions are signed over it, so a transaction for one Solieum network is invalid on any other.

Light client

Software that verifies claims about a chain without holding all of it, using proofs against committed roots. What wallets should be, eventually.

Liveness

The system keeps making progress — transactions land, roots advance. Distinct from safety: a halted chain has lost liveness but lost nobody's funds.

MEV

Maximal extractable value — profit available to whoever orders transactions, by placing theirs around yours. The sequencer page is about constraining exactly this.

Multisig

A wallet requiring M of N keys to act. Better than one key, still custody by a small group. Honest disclosure names M, N, and who holds the keys.

Ordering receipt

The sequencer's signed commitment to a transaction's batch and position, issued before execution. Publishing a different order contradicts a signature it already gave, which anyone holding the receipt and the batch can prove.

Proposer

The party that commits state roots to Solana, under bond. Distinct from the sequencer, which orders and executes — though on Solieum today one node plays both roles.

Reorg

A chain reorganisation — recent blocks replaced by a competing history. Why deposits wait for finality instead of first confirmation.

Rollup

A Layer 2 that executes off-chain and publishes its data to the base layer, so the base layer can adjudicate disputes. If the data is elsewhere, the correct word is validium or optimium. Solieum is an optimistic rollup, and stays one.

Safety

Nothing invalid ever finalises. The property the proof system defends, and the one you should refuse to trade for throughput.

Sequencer

The party that orders and executes transactions and produces blocks. It can delay and reorder; it cannot forge state once proofs enforce. On Solieum today a single operator; a staked, rotating set is a later stage, for ordering only.

Slashing

Destroying a bond as punishment for a provable offence — an invalid root, a double-signed slot. The economic teeth behind the protocol's rules.

Soft confirmation

The sequencer's acknowledgement that a transaction is included. Fast, useful, and revocable. Not finality.

Stage 0 / 1 / 2

The public shorthand for how much trust a Layer 2 still requires. Stage 0 means the operator can still upgrade the contracts; Stage 2 means proofs and timelocks, not people, decide.

State root

A single commitment to the entire L2 state at a point in time. Withdrawals are proven against it.

SVM

The Solana Virtual Machine — the execution environment Solana programs run in, and the one Solieum targets.

Timelock

A mandatory delay between announcing a privileged change and executing it. Only meaningful when longer than the time users need to exit.

TVL

Total value locked — funds a system holds. Relevant here mostly as the number bonds and bounties must be sized against.

Upgrade authority

The key allowed to replace a program's code. On Solieum today a single operator key, which is why the security page names it as the first thing you trust; a multisig and timelock are to be published before mainnet.

Validity proof

A cryptographic proof that execution was correct, checked at commitment time. No challenge window needed — and a silent catastrophe if the prover itself is unsound, hence multi-prover designs.

Validium

Executes off-chain like a rollup but publishes data elsewhere. Cheaper, and the data provider becomes a trust assumption. Solieum's only pre-authorised exception to publishing on Solana, per market and disclosed on that market's page if it ever happens.

Verifier

A node that independently re-derives L2 state and checks the operator's committed roots. Optimistic security depends entirely on these existing.

Witness

The Merkle-proven accounts a disputed instruction touches. They let the one-step verifier re-run that instruction against the agreed pre-state without holding the rest of the state — the shape of Solieum's fraud proof on-chain.