Live on Mainnet
Umbra is live on Stellar mainnet — real zero-knowledge privacy, verified on-chain. Here’s exactly what’s real today and the roadmap to full scale.
Live on Stellar mainnet — real ZK privacy, capped at 100 XLM per deposit
Every shield, private send, and unshield is a real Groth16 proof verified on-chain. Early access — the per-deposit cap stays while we harden, and an independent audit is on the roadmap.
What Umbra hides — and what it doesn’t
Umbra currently provides link privacy, not confidential amounts. On-chain, an observer can see a deposit and a withdrawal and their amounts — what they cannot see is which deposit funded which withdrawal. Umbra is early access: deposits are capped while we harden, and an independent audit is on the roadmap. Everything below is exactly what’s live now versus what’s next.
Readiness scorecard
On-chain ZK verification
LiveGroth16/BLS12-381 verified inside a Soroban contract via CAP-0059 host functions.
Browser proving
LiveProofs generated client-side (snarkjs, Web Worker). Secrets never leave the device.
Cross-device recovery
LivePrivate balance rebuilt from on-chain events using a deterministic wallet-derived seed.
Selective disclosure
LiveEncrypted audit packets under a user-held viewing key. No backdoor.
Mainnet deployment
LiveLive on Stellar mainnet — open, capped-per-deposit early access. Real shields, private sends, and unshields settle on pubnet today.
Trusted setup
RoadmapGroth16 uses a single-contributor setup today; an MPC ceremony (or a transparent system like UltraHonk) is on the roadmap as we lift the cap.
Independent audit
RoadmapA professional audit of the contract, circuits, and BLS verifier path is on the roadmap — the natural next step after the hackathon.
Amount privacy
RoadmapPrivate sends already hide amounts (join-split, hidden on-chain) and withdrawals keep private change; shield + the withdrawn amount stay public. Full confidential amounts on every path is roadmap.
Fee-privacy relayer
RoadmapThe fee payer is visible on-chain; a relayer removes that correlation.
Production indexer
RoadmapScalable note discovery from the deploy ledger onward.
Merkle depth
Live13 levels · 8,192 notes. Every entrypoint does at most ONE Merkle insert (a private send defers the recipient's note to a claim), so a spend fits Stellar's per-tx compute budget at this depth (verified on-chain). A rollup is planned for millions.
Production architecture (designed, not yet built)
Fee-privacy relayer
Submit withdrawals without exposing the fee-payer account. No custody, no secrets.
docs/RELAYER.md
Note-discovery indexer
Scalable balance recovery from the deploy ledger onward. Public data only.
docs/INDEXER.md
Confidential Tokens adapter
A PrivacyRail seam to sit the wallet on CT (confidential amounts, no ceremony).
docs/CONFIDENTIAL_TOKENS_STRATEGY.md