ISS-Based BFT #53 Milestone 1: Core Primitives – Mempool, Availability & Persistence

Milestone 1: Core Primitives – Mempool, Availability & Persistence

| Deliverable | Months after approval | | :---- | :---- | | Estimated Delivery | Month 2 (May 2026 if approved in March) | | Focus | Building the foundational mempool and availability modules with persistence |

Deliverables:

• Mempool module: queuing of ordering requests, batch creation on demand for the availability module.
• Availability module: reliable dissemination of request batches using proofs of availability (PoAs) with configurable quorum thresholds.
• Per-ordering-node storage fairness enforcement with configurable limits on unordered, unexpired PoAs.
• Batch expiration logic based on deterministic derivation from contained requests' max\_sequencing\_time.
• Garbage collection of expired batches at epoch boundaries.
• Persistence layer for PoAs, active dynamic parameters, and peer-to-peer connectivity state.
• Database schema design optimized for cross-module storage efficiency and pruning performance.
• Unit and integration tests for all mempool and availability module functionality.

_Originally posted by @hythloda in https://github.com/canton-foundation/canton-dev-fund/issues/53#issuecomment-4254771406_