LatticeFold+ Batch Verification (research)

Status: research, reserved for future work

LatticeFold+ is an earlier research direction for batch signature verification. It is not active on any network and no production prover exists. The privacy and batch-verification roadmap has since consolidated under SoquObscura (see the whitepaper). This page is kept for reference because the underlying idea remains useful for future work.

LatticeFold+ is a recursive proof composition scheme that aims to compress multiple Dilithium signature verifications into a single constant-size proof. The goal is to let a verifier check a large batch of signatures with a single proof rather than checking each signature individually. Patent pending, Soqucoin Labs Inc. (SOQ-P004).

The problem it targets

Even with PAT's compact commitment, full verification still requires checking each individual Dilithium signature (O(n) work). For blocks with thousands of transactions, that is a bottleneck. LatticeFold+ explores whether recursive lattice folding can reduce the verifier's work to O(1).

How the scheme works

LatticeFold+ uses structured lattice folding to recursively combine verification equations:

flowchart TD
    A["Sig 1 + Sig 2"] --> B["Fold to Proof 1"]
    C["Sig 3 + Sig 4"] --> D["Fold to Proof 2"]
    B --> E["Fold to Proof 3"]
    D --> E
    E --> F["Final proof (constant size)"]

1. Pair signatures and fold their verification equations
2. Recursively fold intermediate proofs
3. Produce a single constant-size proof
4. The verifier checks one proof instead of N signatures

The verification hardness rests on Module-LWE, the same assumption family as ML-DSA-44.

Research targets

The figures below are design targets from the research prototype, not measured production results. There is no shipped prover, so treat them as goals rather than guarantees.

Metric	Design target
Batch size	Up to 512 signatures
Proof size	Constant (independent of batch size)
Hardness	Module-LWE (same family as ML-DSA-44)

Why it is reserved rather than shipped

A batch-verification scheme is only safe to activate once a sound prover exists and the verifier has been audited to reject invalid proofs. Neither condition is met today, so LatticeFold+ is held as a research track and is not enabled on any network. The current privacy work under SoquObscura supersedes it for near-term purposes; the folding idea remains a candidate for a future verification-scaling effort.

Relationship to PAT

PAT (shipped and active from genesis) and LatticeFold+ (research) target different halves of the same problem:

	PAT	LatticeFold+
What it does	Commits to N signatures	Aims to verify N signatures in O(1)
Status	Active from genesis	Research, not active
Opcode	OP_CHECKPATAGG (v2)	OP_CHECKFOLDPROOF (v3), reserved

For the current, active batch-attestation mechanism, see PAT.