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Resources

This page provides a collection of resources on Ouroboros Leios, including technical papers, presentations, and videos.

Technical documentation​

Leios CPS​

Summary:​

  • Cardano’s mainnet periodically faces congestion, with block utilization exceeding 90%, delaying transactions and impacting user experience, especially for use cases like airdrops, DEXes, oracles, and DApps. As new applications and bridges (eg, Cardano-Midnight, Cardano-Bitcoin) increase demand, current throughput (~12 TPS max) lags far behind competitors like Solana (7229 TPS). In Ouroboros Praos, security constraints (eg, 5-second block relay within a 20-second slot) limit block size and script execution, underutilizing network resources. This CPS calls for research into scaling solutions like Ouroboros Leios to boost transaction volume, size, and execution units, while ensuring predictable processing times for time-sensitive applications. Goals include defining stakeholder needs, safely increasing limits, and leveraging underused resources — all without compromising security or raising node costs. Historical data shows frequent near-full blocks and Plutus execution bottlenecks, underscoring the urgency as Cardano aims for nation-state-scale usage by 2030.

Leios CIP​

Summary

CIP-0079 introduces Ouroboros Leios as a long-term solution to raise Cardano throughput beyond the limits of Ouroboros Praos. The CIP explains the rationale and provides a high-level protocol design.

Leios research paper​

Summary

The paper presents Leios, a protocol overlay that transforms low-throughput PoW or PoS systems into high-throughput chains, achieving near-optimal throughput of (1 − δ) σ_H (where σ_H is the honest-stake fraction and δ > 0). Leios addresses adversarial tactics such as message bursts and equivocations via:

  1. Concurrent input-block (IB) generation
  2. Endorser blocks (EBs) with data-availability proofs
  3. A seven-stage pipeline for uninterrupted processing
  4. Freshest-first diffusion with VRF-based timestamps
  5. Equivocation proofs to cap malicious spam.

Applied to Ouroboros, Leios yields a scalable, secure layer-1 for Cardano while maintaining settlement guarantees and supporting dynamic participation.

Videos​

Presentations​

Tools and simulations​

Development resources​