Blindapp

Blind Wallet is a mobile wallet designed to give users complete privacy when managing ERC-20 tokens. Using the Unlink SDK, Blind Wallet employs Zero-Knowledge Proofs (ZKPs) to ensure that every transaction is private, hiding details such as the sender, amount, and recipient on the blockchain.

Key features include:

Depositing tokens from an EOA wallet into the Unlink privacy pool for secure, private transactions Transferring tokens to other Unlink addresses, with no on-chain trace of the sender, recipient, or amount Withdrawing tokens to any Ethereum-compatible address Viewing private balances without exposing sensitive data

Blind Wallet solves the problem of privacy in public blockchains, where every transaction can be observed and linked to a user’s balance or history. By using the Unlink privacy pool, Blind Wallet enables full confidentiality within the pool, ensuring that only the user has control over their financial data.

The core of Blind Wallet’s privacy features is powered by Zero-Knowledge Proofs (ZKPs), which are generated client-side using the Unlink SDK. This cryptographic technique allows the validation of transactions without revealing any sensitive data, such as the transaction amount, sender, or recipient. These proofs ensure privacy while maintaining the integrity of the transaction.

When a user initiates a private transaction:

The Unlink SDK generates a ZKP that proves the validity of the transaction without exposing any details. The proof is then submitted to the on-chain privacy pool, where a nullifier is used to prevent double-spending. A commitment is added to a Merkle tree, ensuring that each transaction can be securely verified while keeping all transaction data confidential.

On the device, keys are generated securely within the native app, combining an Unlink mnemonic and the user's EOA private key. These keys are only transmitted to the backend temporarily and are never stored server-side, ensuring that sensitive information never leaves the user's control. Communication with the backend is done over HTTPS, and native secure storage on the device ensures that keys are protected against unauthorized access.

In terms of the architecture, the system integrates with Ethereum-compatible blockchains using the EVM (Ethereum Virtual Machine), and the privacy pool acts as a secure intermediary for off-chain transactions. The entire process generating proofs, submitting to the pool, and verifying transactions is done without exposing any public trace of user activity.

To maintain scalability and performance, Blind Wallet leverages the Sepolia testnet for development and testing, enabling efficient validation of ZKPs before full deployment.