Scaling at a (Security) Cost: Unveiling the Security Assumptions Behind Today's Blockchain Layer 2 Scaling Solutions
Reviewing baseline L1 security assumptions and analysing the trade-offs introduced by Layer 2 solutions.
Talk given at Chalmers University of Technology, Gothenburg, June 17, 2025. Part of a research stay at Chalmers’ SecuraLab.
Event page: cse.chalmers.se
Abstract
Layer 2 (L2) solutions have emerged as the primary approach to scaling permissionless blockchains. However, each L2 design introduces its own set of security assumptions that differ from — and often weaken — those of the underlying Layer 1.
This talk reviews the baseline security assumptions of permissionless L1 blockchains, then analyses the additional assumptions introduced by different L2 architectures: Payment Channel Networks, Optimistic Rollups, Zero-Knowledge Rollups, Validium, and Volition. The comparison highlights how each design trades off censorship-resistance, data availability, and decentralisation in exchange for scalability, providing a framework for practitioners assessing L2 threat models.
Links
Based on the work: “A Taxonomy of Security Analysis of Blockchain Layer 2 Scalability Solutions and Future Directions”.