Lattice-BP++ Confidential Transactions (research)¶
Status: research, superseded by SoquObscura
Lattice-BP++ is an earlier research design for quantum-safe confidential transactions. It is not active on any network, and its range-proof soundness enforcement is not complete (the prover is research-only). The confidential-transaction roadmap has since consolidated under SoquObscura (see the whitepaper). This page is kept for reference.
Lattice-BP++ explores quantum-safe confidential transactions: hiding transaction amounts while still letting validators confirm that no coins are created or destroyed. Patent pending, Soqucoin Labs Inc. (SOQ-P002).
What it aims to do¶
A standard Soqucoin transaction exposes the amount sent. A confidential transaction would replace the amount with a cryptographic commitment and carry a range proof showing the hidden value is within valid bounds.
| Field | Standard TX | Confidential TX (goal) |
|---|---|---|
| Sender | Visible | Visible |
| Receiver | Visible | Visible |
| Amount | Visible | Hidden (commitment) |
| Validity | Verifiable | Verifiable via range proof |
Technical design¶
Commitments¶
Lattice-BP++ uses Module-LWE commitments instead of Pedersen commitments (which rely on elliptic-curve discrete-log and break under Shor's algorithm):
| Parameter | Value |
|---|---|
| Lattice dimension | n=256 |
| Modulus | q=8,380,417 |
| Hardness | Module-LWE/SIS |
| Security level | NIST Level 2 (quantum-safe) |
These are the same lattice parameters as NIST's ML-DSA (Dilithium) standard.
Range proofs¶
The design goal is a proof that a committed value is within a fixed non-negative range without revealing it, using an inner-product argument adapted to the lattice setting.
Soundness enforcement is incomplete
In the current in-tree code the full norm enforcement for the range proof is planned but not finished, and the prover is research-only. Do not treat the range proof as a completed zero-knowledge guarantee. This gap is one of the reasons the work moved to SoquObscura.
Ring signatures¶
For sender privacy, the design includes Module-LWE ring signatures that hide the real spender among decoys. The implementation supports a configurable ring (default 11, maximum 32 members).
Why it is superseded¶
Lattice-BP++ established the lattice-commitment and range-proof direction, but its proof size and incomplete soundness enforcement made it unsuitable to ship as-is. SoquObscura carries the confidential-transaction work forward with a revised construction. Lattice-BP++ is retained here as background.
Why not classical Bulletproofs¶
Classical Bulletproofs++ (used by Monero and Mimblewimble) rely on the elliptic-curve discrete-log problem, which a quantum computer running Shor's algorithm breaks completely. The lattice-based approach replaces that math with assumptions that resist both classical and quantum attack, at the cost of larger proofs.
The research code lives in the Soqucoin repository: github.com/soqucoin/soqucoin.