Post-Quantum (PQ) Interop #49, July 29, 2026

Protocol Calls & happenings
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Meeting Time: Wednesday, July 29, 2026 at 14:00 UTC (60 minutes)

GitHub Issue

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Meeting Summary:

This was a client update meeting where teams discussed progress on DevNet testing and LeanVM integration. Parthasarathy reported running full client tests on DevNet that identified justification and finalization issues after 7,000-8,000 slots, and received a PR from the EEP Lambda team for Lean Quickstart. Shariq’s team focused on optimizing aggregation time to match Lambda’s performance and integrating the main branch of Lean multisig. Mihir’s team fixed syncing issues for Lantern and implemented support for the main branch of LeanVM, noticing significant stability improvements with final D slot consistently remaining 3 slots behind the head slot. Pablo’s team merged Server Spend Events APIs and tested with 64-node devnets, achieving better stability with time to finality dropping to under 25 slots when using the latest zkVM version. Bankat’s team shifted focus to preparing for newer Lean VM, integrating the new signing and aggregation flow on an experimental branch. Boma released an optimized image with metrics fixes and was testing the updated LinVM commit locally. Emil provided updates on binary field work, mentioning progress on a big extension field version that enables small proofs with potential 3x performance improvements. Thomas shared updates on SSE specifications transfer to the Ethereum organization and ongoing research on binary fields techniques. The conversation ended with recommendations for teams to first test single-client DevNets before multi-client interop and to test the main branch of LinVM for additional speed improvements.

Click to expand detailed summary

Parthasarathy reported issues with DevNet client testing, where both justification and finalization stopped after 7,000-8,000 slots, and identified delayed aggregated signatures as the cause. Shariq’s team is working to optimize aggregation time to match Lambda’s performance and is integrating the main branch of lean multisig, with plans to test interop before merging. The team will continue monitoring these issues and will notify everyone of progress, while Thomas mentioned upcoming schedule changes including no calls next week and weeks after, followed by potential reorganization of meeting frequency.

Mihir reported that syncing issues for Lantern have been fixed and support for the main branch of LeanVM has been implemented, with testing showing significant stability improvements including consistent 3-slot finality delays. Pablo announced completion of Server Spend Events APIs and tooling for visualizing message slots, with testing across 64-node devnets showing improved stability when using the latest ZKVM version, though some reorgs remain with 3% of logs being reorganized recently. Both teams are continuing to scale their testing environments, with Mihir waiting for additional servers and Pablo running further tests with 512 validators in a single server configuration.

The team shifted focus from operational hardening to preparing for the newer lean VM, with Bankat reporting that migration work included integrating the new LeanVM signing and aggregation flow on an experimental branch and updating clients to match new formats. Bankat noted they deliberately kept the work on a separate branch to avoid affecting current multi-client interop testing. The team discussed the possibility of agreeing on a single LeanVM version to simplify future work, though this topic appeared to be open for discussion.

Boma reported that an image with optimization and metrics fixes was released last week, and they have been testing LinVM commits locally for three days with plans to make an official image release this week. Emil provided an update on the binary version of LinVM, mentioning progress on a version with a big extension field that enables small proofs, though significant cleaning and rework are still needed before merging to the main branch. Emil expressed hope that the performance improvements would result in approximately 3x speed gains.

Thomas provided updates on two main areas: specifications and research. The team successfully transferred SSE specifications to the Ethereum organization with help from the Content2Spec team, and ongoing research continues exploring binary fields techniques with improvements to the proving system. Thomas encouraged teams to test single-client DevNets for better stability before attempting multi-client interop, and recommended testing the updated main branch of LinVM which includes a smaller XMSS variant. Mega requested an API option to enable/disable the bump arena allocator for memory management, particularly for running multiple nodes on a single server.

Next Steps:

  • Parthasarathy: Review the PR on Lean Quickstart from the EEP Lambda team and run an only Lambda devnet with the latest lean VM, then report back on the results.
  • Shariq: Test Interop with the main branch of lean multisig, and once tested, merge it and notify everyone.
  • Mihir: Test with other clients once they have support for the main branch of LeanVM.
  • Bankat: Regenerate required keys, refresh test vectors, and run Interop testing once a single LeanVM version is agreed upon by all clients.
  • Boma: Round up the optimization improvements this week and make an official image release based on that.
  • T.: Implement a way in the API to activate/deactivate the bump arena allocator for a low memory mode and a high memory mode.
  • All client teams: Test single-client DevNets with their own client for stability before attempting multi-client interop.
  • All client teams: Test the main branch of LeanVM with the smaller XMSS variant and ensure compatibility with the new signature scheme.

Recording Access:

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YouTube recording available: https://youtu.be/pIGV-YbCLTE