Meeting Time: Wednesday, July 22, 2026 at 13:00 UTC (60 minutes)
Meeting Summary:
The meeting focused on post-quantum transaction signatures, specifically discussing parameter variations for Sphinx signatures. Alessandro and Matteo presented their work on different parameter configurations for Sphinx, demonstrating four distinct signing variants optimized for different use cases including fast signing, gas savings, and cold storage applications. They showcased a demo wallet implementation that allows users to switch between these different parameter sets without changing the underlying smart contract, highlighting the flexibility of account abstraction. The presentation included technical details about key generation, signing processes, and how the different parameter sets balance security levels, signature sizes, and verification costs. Antonio raised questions about aggregation compatibility, key management, and implementation details, particularly regarding key generation requirements for each parameter set. The discussion concluded with plans to fork the ERC repository to begin formalizing these implementations as an ERC standard.
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Antonio led a meeting on post-quantum transaction signatures, focusing on hash-based signatures as the target approach. The team discussed their progress toward JSTAR with PQ Lynn Sphinx, noting they have three releases remaining before shipping. Matteo was scheduled to present on behalf of RivaLabs regarding some signature variants.
Alessandro presented work on optimizing Sphinx parameters, introducing different parameter sets tailored for specific use cases such as optimizing signing time or gas cost of verification. He explained how these parameter sets can be combined using account abstraction on the AVM, allowing users to have multiple authorized signers (e.g., a fast signer and a gas-saving signer) for a single account. This approach provides flexibility by enabling users to choose the appropriate signing method based on their specific needs.
Matteo demonstrated a showcase wallet implementation using Sphinx that allows users to select different signing configurations including standard, gas saver, and quick signer options. The wallet supports four different signing setups that can be used without changing anything in the implementation, giving users flexibility to choose based on their specific needs like trade timing or data transmission requirements. Antonio asked about potential overlap between the fourth configuration and future work, to which Matteo explained that while the fourth option (quick signer) is generally faster and cheaper, it’s still necessary to rotate signers in normal use cases.
Matteo and Antonio discussed using Sphinx for different use cases, highlighting the possibility of optimizing for various parameters such as transaction speed, signature size, and gas cost. They explored how different configurations, including the use of force, could address specific needs like cold storage or hot wallet scenarios. Alessandro provided additional context on the different use cases and parameters, emphasizing the flexibility of the system to adapt to varying requirements.
Alessandro explained that users can choose different NIST security levels by using appropriate parameter sets and on-chain verifiers. Matteo discussed the trade-offs between gas savings and signing time, noting that while gas-saving parameters reduce verification costs, they can significantly increase signing time. Antonio raised a question about using aggregation for Ethereum, suggesting that fast verification would be beneficial due to reduced hashing requirements, though Matteo explained that while gas savings are possible, the increased signing time could be problematic for time-sensitive transactions like trading.
Matteo demonstrated a wallet implementation using account abstraction with four different signing modes, explaining that the system uses smart contracts to handle signing without requiring knowledge of private keys. The key generation process occurs on-demand when needed, with each signing mode requiring its own parameter set and key generation. Antonio announced plans to fork the ERC repository to begin documenting these specifications, starting with a Sphinx-based implementation and covering details about abstraction, key creation tools, and potential key rotation features.
Next Steps:
- Antonio: Fork the ERC repository of Ethereum and start a new ERC to cover the discussed topics (Sphinx, account abstraction, key rotation, etc.). Post the link on the Telegram channel and start working on it on Monday.
- Antonio: Add contributors to the new ERC repository who ping him on the Telegram channel.
- Alessandro and Matteo: Be available to answer questions about their demo and presentation.
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YouTube recording available: https://youtu.be/g1vZjqT4C5A