Post Quantum transaction signature (PQTS) Breakout #13

Protocol Calls & happenings
1

Agenda

  • PQ Sigs at Circle- Mira Belenkiy

Meeting Time: Wednesday, August 19, 2026 at 13:00 UTC (60 minutes)

GitHub Issue

1 Like
2

Meeting Summary:

The meeting focused on post-quantum transaction signatures, with Mira Belenki from Circle presenting Circle’s use cases and transition concerns. Mira explained Circle’s position across ARK blockchain, stablecoin issuance, and payment services, and highlighted the risk of ecosystem fragmentation with many signature schemes and parameter sets. She described operational needs for stateless signatures due to high transaction volumes and distributed hot wallets, concerns about frequent key rotation, and the importance of interoperability over raw performance. Mira discussed Circle’s experiments with SLHDSA and the use of batching for gas efficiency, as well as the challenge of legacy smart contracts using ECRecover. She proposed a hotfix approach to reinterpret ECDSA signatures via ECRecover, using the V field as a version and R/S as pointers to a lookup table for post-quantum public keys and signatures, possibly integrated with frame transactions. Antonio and others asked about Circle’s products, hardware support, batching details, and the practicality of the ECRecover proposal, and Mira clarified that most work was still in the design phase. Antonio also mentioned the upcoming ACDE discussion and the community’s shift away from lattice-based precompiles towards hash-based signatures.

Click to expand detailed summary

Antonio opened the Post Quantum Transaction Signature Breakout Room meeting and welcomed participants, noting they would start a few minutes late to accommodate late arrivals. He introduced the agenda, which would include a presentation on hash-based stateless signatures and elliptical cryptography, with Mira Belenki from Circle as the sole presenter. The meeting began with technical checks and introductions, with Antonio expressing excitement about Mira’s presentation due to her extensive experience in cryptography.

Mira presented Circle Research’s approach to post-quantum signature implementation, highlighting their concerns about ecosystem fragmentation across 30 different blockchains. She explained that Circle’s high-volume transaction signing operations (30,000-70,000 daily) make certain parameter sets problematic due to key rotation requirements, favoring stateless solutions like Sphinx over parameter sets that would require frequent key rotation. Mira also discussed Circle’s strategy for handling existing smart contracts using ECRecover by proposing to reinterpret the V value as a version number to support post-quantum signatures while maintaining ABI compatibility.

Antonio asked Mira about the use cases presented, specifically whether they were for stablecoin USDC or other products. Mira clarified that while they don’t mint 30,000 times per day, most of the use cases were for their payment products, particularly Circle Payment Network. The discussion then shifted to a question from Gottfried about modularizing signature variations, with Mira explaining different post-quantum signature schemes and their potential parameter sets.

Mira confirmed that their blockchain project ARC is in the design phase and has released a precompile for SLHDSA using SHA-2 for testnet, with mainnet launch planned for mid-September. She explained that interoperability with Ethereum is their top priority over performance, and while they use BLS for consensus, they are not currently prioritizing post-quantum signature performance improvements. Mira clarified that ARC is an L1 public blockchain competing with solutions like Tempo and Stripe, with hardware wallets primarily used for cold storage rather than hot wallets.

The team discussed consensus mechanisms and batching techniques for handling high transaction volumes. Mira explained their batching approach using 3009 transfers with authorization transactions, though without concrete latency numbers. The main focus was on Mira’s proposed solution for quantum-resistant signatures, which involves creating a smart contract registry to map public keys to Ethereum addresses, allowing the system to maintain compatibility with both ECDSA and post-quantum signatures through frame transactions. Antonio expressed interest in this approach and suggested creating a formal EIP document, while Tiago mentioned they are already using EIP 8373 for PQ anchored key binding.

The team discussed Mira’s proposal for a new signature scheme using R and S values, with Mira explaining how the 64 bytes could be split into three parts: a 20-byte address, a 20-byte index for public keys, and a 20-byte index for signatures, with the V value used to identify signature schemes. Antonio expressed interest in seeing a concrete instantiation of the proposal and noted that while Lattice was previously proposed for Ethereum precompiles, the team has since moved toward hash-based signatures. Antonio announced he will present at next Thursday’s AllCoreDev meeting about post-quantum transaction signatures and the shift away from Lattice precompiles.

Next Steps:

  • Mira: Create a more formal document, potentially an EIP, for the ECRecover hotfix proposal to make it work with frame transactions.
  • Mira: Reach out to the person who mentioned using EIP-8373 for PQ anchored key binding, via the email provided in the chat.
  • Antonio: Present a recap of the 13 instances of post-quantum transaction signatures at the next ACDE meeting, emphasizing the move away from lattice-based signatures.

Recording Access:

3

YouTube recording available: https://youtu.be/pvZMN5r7wdc