zkBob

• Name: zkBob
• URL: https://zkbob.com/
• Category: privacy payments application / compliance-mediated shielded-transfer wallet
• Tags: ethereum-ecosystem tron-ecosystem
• Summary: zkBob is a privacy payments app with a compliance wrapper, not a generic mixer and not a separate privacy chain. The useful split is the shielded pool, the relayer path, and the screening or limits policy sitting in front of withdrawals and transfers.
• What it does:
  • Lets users deposit supported assets into zkBob pools and then send or receive funds privately through zk addresses without exposing counterparties or transfer amounts onchain
  • Runs on Polygon, Optimism, and Tron, with first-party docs highlighting USDC on Polygon, USDC and ETH on Optimism, and USDT on Tron
  • Uses a relayer layer to calculate zkSNARK proofs, submit transactions to the pool in sequence, and abstract gas fees from end users
  • Exposes a web application plus SDK and open-source contract repositories so users and integrators can interact with the privacy system directly or extend it
  • Adds compliance-oriented controls including wallet screening, deposit and withdrawal limits, pool-size caps, and geography / eligibility restrictions
  • Publishes security-audit references for core contracts and frames the application as an open-source decentralized protocol used at the user’s own risk
• Key claims:
  • The docs describe zkBob as an open-source, decentralized stablecoin-based privacy application for everyday users rather than as a custodial service
  • The official overview says the core stack consists of the zkBob Pool, Bob Token contract, Relayer, Operator Manager, and Application frontend
  • The docs say zkSNARKs are used to anonymize senders, receivers, and amounts, while the relayer helps manage proof generation and pool interaction
  • The compliance docs state that suspicious wallets can be blocked through TRM-integrated screening and that deposit / withdrawal limits plus pool caps are used to reduce abuse
  • The project explicitly restricts some users and jurisdictions, including politically exposed persons as well as users in the UAE and US, which is an important clue about how the team wants the product positioned
  • The security docs point to a ChainSecurity audit covering zkBobPool, BOBToken, and BobVault, with one high-severity issue reported as corrected
• Whitepaper: No canonical standalone zkBob whitepaper or litepaper was surfaced in this pass. The official docs portal, contracts repository, and linked audit materials appear to be the clearest current primary sources; see ../whitepapers/zkbob-primary-sources-2026-04-27.md.
• Sources:
  • https://zkbob.com/
  • https://docs.zkbob.com/
  • https://docs.zkbob.com/zkbob-overview/readme.md
  • https://docs.zkbob.com/implementation/high-level-overview.md
  • https://docs.zkbob.com/zkbob-overview/compliance-and-security.md
  • https://docs.zkbob.com/resources/security-audit.md
  • https://github.com/zkBob
  • https://github.com/zkBob/zkbob-contracts

Internal linkages

• Best smart-contract privacy contrasts: railgun and privacy-pools.
• Keep the note on relayered private payments with explicit screening and transfer limits, not on generic privacy-tech rhetoric.

Control surface

• The leverage sits in relayer operation, wallet-screening policy, deposit and withdrawal limits, geography gating, and the exact conditions under which a private transfer is allowed to proceed.

• The zk system matters, but the product risk lives in the compliance wrapper around it.

• Read zkBob as a constrained privacy-payments app, not as a neutral anonymity rail.

• Last reviewed: 2026-06-18 UTC