A new smart wallet application called CzechOut has launched with biometric authentication technology that allows users to make instant payments using facial recognition and personal PIN codes. The system combines Face ID security with Yellow Protocol's state channel technology to enable gasless, off-chain transactions with no waiting time for confirmation.
What to Know:
- CzechOut encrypts facial data with email and PIN combinations, storing identity information through smart contracts while preserving user privacy
- The wallet supports two transaction types: EIP-7702 native account abstraction and Yellow Network's chain-abstract state channels for instant payments
- Users can recover lost access through zkRecovery system using zero-knowledge email proofs and web verification without re-registering biometric data
The application, built on the Yellow SDK, addresses common digital wallet limitations by upgrading standard externally owned accounts (EOAs) into smart accounts at no gas cost to users. This upgrade enables access and control from any trusted device equipped with Face ID capabilities, particularly valuable when users lose their primary devices or physical wallets.
CzechOut's payment system offers flexibility through dual transaction pathways. EIP-7702 transactions provide native account abstraction support using only facial recognition and PIN authentication. Yellow Network's state channel transactions operate off-chain, eliminating gas fees and confirmation delays while maintaining chain-abstract functionality.
The wallet dashboard includes comprehensive asset management features. Users can view token balances, monitor transaction histories, and collect Blockscout merits when utilizing Yellow state channels for payments. The zkRecovery feature represents a significant security advancement. Users can reset their PINs through zero-knowledge email proofs and web verification with vlayer technology, proving email ownership and demonstrating familiarity with their account's transaction patterns without exposing sensitive identity information.
Technical implementation relies on @vladmandic/human for real-time browser-based facial recognition. Captured facial data converts into stable embedding vectors, with credentials encrypted client-side using hashed combinations of user emails, secret PINs, and additional security parameters. The entire process operates through circum zero-knowledge circuits to prevent on-chain secret revelation.
The encrypted biometric hash registers with the Registry Smart Contract, mapping user identities to EOA wallet addresses.
A relay account waives gas fees during the EOA-to-smart-account upgrade process, with results visible through Blockscout explorer integration.
Yellow Network's Nitrolite SDK integration enables seamless gasless experiences. User funds deposit into off-chain state channels upon registration. Payment initiation triggers recipient registration checks, enabling instant off-chain fund transfers with zero latency and no fees for registered users. This system particularly benefits micro-payments and in-store transactions requiring speed and cost efficiency.
The recovery system generates email proofs demonstrating registered email ownership alongside web proofs showing account familiarity. These proofs undergo verification through contracts modified from vlayer's email and web proof templates. Successful verification permits secure PIN resets without identity exposure or biometric re-registration requirements.
Zero-knowledge circuit contract entry points ensure private credential validation during face-PIN verification and recovery processes.
CzechOut incorporates a reward system built on Blockscout APIs to encourage Yellow's off-chain infrastructure adoption. The system monitors state channel transaction routing, awarding Blockscout merits to users transacting with supported merchant addresses or meeting specific rulesets. Rewards record in hybrid on-chain/off-chain ledgers, directly linking incentives to decentralized transaction behaviors.
Closing Thoughts
CzechOut represents a convergence of biometric security, zero-knowledge cryptography, and Yellow Protocol's state channel technology. The application addresses fundamental digital payment challenges through gasless transactions, instant confirmations, and robust recovery mechanisms while maintaining user privacy and security standards.