Execution, Sequencing & Dispute Game (Orbit)

Optimistic Rollup on Orbit: Authra runs as an Arbitrum Orbit L3. Ordering is performed by a sequencer (initially a primary with hot standby), and state transitions execute on Nitro. Safety derives from optimistic fraud proofs (Arbitrum BoLD) that allow any permissionless challenger to dispute an invalid state transition; disputes resolve on the parent chain, inheriting L2/L1 guarantees. Users retain censorship resistance via the Delayed Inbox “force-inclusion” path if the sequencer withholds transactions. Timeboost priority auctions remain chain-opt-in and, if enabled, are paid in $ATRX per governance policy. The consensus process works as follows:

• Batching of Proofs: TruePing submissions are aggregated off-chain into Merkle trees; blocks commit the Merkle root for hundreds or thousands of proofs rather than each report individually. This preserves verifiability (any proof can be checked against the on-chain root) while keeping throughput high and fees low; commitments are posted to Authra L3 and anchored upstream to Arbitrum One and Ethereum L1.

• Anchoring to Ethereum L2: Authra deploys as an Arbitrum Orbit L3 that settles to Arbitrum One (L2), which itself settles to Ethereum (L1). This gives us Ethereum-grade security properties with significantly lower fees and faster confirmations, while keeping a straightforward path to L1 data availability if/when required.

• Roles & incentives: At the chain layer we speak of sequencers and challengers “(not BFT validators)”. Challengers post bonds and are rewarded for successful fraud proofs; spam or malicious challenges are penalized per governance parameters. Operational policies for inclusion, liveness/rotation, logging, and DAC data-availability attestations remain as specified elsewhere in this section.

• Non-Consensus Node Roles (bountied): To harden ingestion and improve interoperability, Authra defines non-consensus roles with bounties:

  • Scanner — log/metrics scanners watching pipeline health, anomaly spikes, replayability.  

  • Indexer — low-latency chain/index services backing queries, heatmaps, and forensic drill-downs.  

  • Bridge/Relayer — cross-chain feeds of summarized commitments and SLA signals.

These roles do not affect safety (optimistic proofs handle safety) but expand resilience and developer utility.