ZKProof 5.5 in Barcelona was a blast! We focused on standardization, and all the 100 participants, well, participated! :slightly_smiling_face:  Here’s summary of the talks, for those who couldn’t make it, but also as reference for the workgroups we formed.

James and Kimberlee clearly explained the SIEVE IR (slides here), a collaborative specification enabling interoperability between frontends and backends. They invited the community to learn from their experience, presenting the IR as an extensible standard that could outlive the SIEVE program. By sharing lessons learned, they recruited participants to advance this specification effort, aligned on goals like flexibility and scalability, and built momentum to evolve these standards beyond SIEVE.



  • The IR provides a circuit representation of ZK proofs, designed through a formal process with multiple SIEVE teams.
  • Enables frontends to interface with diverse backends, promoting modular interoperability.
  • Language features like types, gates, functions demonstrate extensibility.
  • Memory management and field conversions handle large proofs across prime fields.
  • Tools built on IR show range of applications in vulnerabilities, policy enforcement.

Lessons Learned:

  • Understand different visions and find common ground across teams.
  • Have a standard process with unbiased arbiter to move things forward.
  • Flexibility and scalability were critical goals to support innovation.
  • Specification has proven useful enough to continue leveraging.

Looking Ahead:

  • IR could become a broader standard or interoperate with Plonk.
  • Community should try it out and consider evolving it.
  • Can build plugins to extend functionality without syntax changes.
  • Resources available on GitHub to get started.
  • Continued feedback will be important as standards iterate.

Key Takeaways:

  • IR provides a collaborative, extensible specification for ZK circuits.
  • Enables modular interoperability between frontends and backends.
  • Valuable lessons on designing standards by committee.
  • Opportunity to build on this and advance ZK standards.
  • Community involvement will be critical to evolve IR beyond SIEVE.