zkTLS Overview

What is zkTLS?

zkTLS (Zero-Knowledge TLS) lets users prove claims about data from HTTPS websites — without revealing the raw data and without the website's cooperation.

A user opens a normal TLS session with a web2 server (bank, government portal, employer HR system). A verifier node participates via MPC so no single party holds the full session key. After the session, the user generates a ZK proof about a specific claim ("my balance exceeds $10K") and submits it on-chain.

The server sees a normal HTTPS request. The on-chain verifier sees a valid Groth16 proof. Nobody sees the underlying data.

How Root14 Uses zkTLS

Root14's r14 zktls crate bridges web2 data into Soroban-verifiable proofs:

1. Fetch    — TLS oracle fetches data from a URL, produces TlsAttestation
2. Commit   — Poseidon(value, nonce) binds the attested value
3. Prove    — Groth16 range proof over the committed value
4. Verify   — r14-core.verify() on Soroban — same interface as every other module

The key insight: the zkTLS circuit is the range circuit. The attestation provides the witness (value + nonce), and the range circuit proves the claim. No new circuit needed.

Architecture

┌─────────────┐     ┌──────────────┐     ┌──────────────┐
│  Web2 Server│────→│  TLS Oracle  │────→│ TlsAttestation│
│  (HTTPS)    │     │              │     │  value+nonce  │
└─────────────┘     └──────────────┘     └──────┬───────┘
                                                │
                                    ┌───────────▼──────────┐
                                    │  Poseidon Commitment │
                                    │  cm = H(value, nonce)│
                                    └───────────┬──────────┘
                                                │
                                    ┌───────────▼──────────┐
                                    │  Range Circuit       │
                                    │  prove min ≤ val ≤ max│
                                    └───────────┬──────────┘
                                                │
                                    ┌───────────▼──────────┐
                                    │  r14-core.verify()   │
                                    │  on Soroban          │
                                    └──────────────────────┘

TLSNotary Integration

Root14 uses TLSNotary as the underlying attestation protocol:

• MPC-TLS: Splits the TLS session key between user and notary via 2PC — neither party can forge data
• Selective disclosure: User chooses which fields to reveal/prove
• No server changes: The web2 server sees a normal HTTPS client

Current status: The TLS attestation source is simulated (mock oracle), but everything downstream is real — Poseidon commitments, Groth16 proofs, and on-chain verification on Stellar testnet. The r14-examples/zktls demo performs a full deposit + private transfer on testnet. Real TLSNotary integration is the next milestone.

What You Can Prove

Claim	Data Source	On-Chain Reveals
Balance > $10K	Bank website	Nothing about actual balance
Age ≥ 21	Government ID portal	Nothing about birthdate
Employed at Company X	HR portal	Nothing about salary
Credit score > 700	Credit bureau	Nothing about score
Not on sanctions list	OFAC database	Nothing about identity
Accredited investor	Brokerage account	Nothing about net worth