Wallet Firewall: A Pre-Signing Security Layer for EVM Wallets

Description and use

Wallet Firewall stops accidental fund loss by analyzing EVM transactions before signing and providing clear verdicts and explanations.

Problem

Users often sign malicious EVM transactions unknowingly, leading to fund loss.

Outcome

Wallet Firewall prevents accidental signing of risky transactions by providing pre‑signing analysis and user‑friendly explanations, reducing potential fund loss.

Workflow

• Decode raw calldata to function selectors
• Fetch contract bytecode, balance, and nonce (Intel)
• Simulate transaction with eth_call to catch reverts
• Score risk deterministically (0‑100) with hard blocks
• Translate findings to plain English via LLM
• Gate sign button if verdict is BLOCK

Evidence

Wallet Firewall solves this, before you sign, it decodes the transaction, checks the contract, and scores the risk.

Source

It returns one of three verdicts: SAFE, REVIEW, or BLOCK. Each verdict comes with a plain‑language explanation, so you know exactly why a transaction is dangerous before your funds leave your wallet.

Source

The AI Part: Security tools cannot rely on LLMs to make final decisions, because LLMs hallucinate and are non‑deterministic. Wallet Firewall uses a deterministic risk engine (hardcoded HARD_BLOCK signals and a 0‑100 scoring system) to give the final say.

Source