ZKProof 5.5 in Barcelona was a blast! We focused on standardization,and all the 100 participants, well, participated! 
Here’s summary of the talks, for those who couldn’t make it, but also as reference for the workgroups we formed.
Peter illuminated a promising new paradigm for efficient zero-knowledge proofs using VOLE-in-the-head (slides are here). With crisp clarity, he mapped out how this novel approach builds on the VOLE tool from multi-party computation to enable simple, high-performance proofs with minimal cryptographic assumptions. His articulate explanations revealed the power of VOLE for building homomorphic commitments, as well as the elegance of making interactive VOLE proofs non-interactive. Peter presented the FAEST signature scheme, which achieves similar performance to hash-based signatures under only AES security, and provides post-quantum signatures under 5KB and fast signing/verification.
VOLE Functionality:
- VOLE allows a prover to commit to a vector that the verifier can evaluate. This provides a linearly homomorphic commitment scheme.
- Peter demonstrated how VOLE commitments can be used for circuit proofs, with local operations for linear gates and simple techniques for proving multiplications.
VOLE-in-the-Head:
- The prover secret shares the witness and converts the shares into a set of VOLE inputs.
- A challenge from the verifier determines which commitments to open, allowing verification.This approach is far more efficient than heavy MPC computation.Advantages:
- Simplicity of constructions make VOLE proofs easy to explain and implement.
- High performance for prover as computations use VOLE commitments.
- Minimal cryptographic assumptions, just symmetric primitives.
- Concrete overhead as low as 10-16 bits per AND gate.Application to Signatures:
- Peter presented the FAEST signature scheme using VOLE proofs of AES computation.
- Achieves similar performance to hash-based signatures under only AES security.
- Signatures under 5KB and fast signing/verification.
- Overall, Peter made a compelling case for exploring VOLE-in-the-head as a new paradigm for simple and practical zero-knowledge proofs, opening up potential new applications.