- Blind signing remains one of DeFi’s most dangerous everyday risks because users often approve smart contract transactions they cannot read.
- The Bybit hack showed how private keys can stay protected while a malicious approval still drains assets.
- ERA Wallet introduces ERA Lens™, an on-device transaction parsing engine that turns raw calldata into plain-language details before signing.
On May 12, the Ethereum Foundation and an Ethereum Working Group of wallet developers and security firms launched Clear Signing, an open standard for readable Ethereum transaction approvals. The announcement called blind signing a structural flaw linked to billions in user losses, including the Bybit hack.
Blind signing has often been treated as a wallet UX issue, a user education issue, or a warning screen issue. Users need to understand what a transaction will do before approval, otherwise the final confirmation screen becomes a weak security control.
Taking the Bybit case as an example, security analyses described a workflow where signers believed they were approving a routine transfer, while the underlying transaction redirected control of the wallet proxy to an attacker contract.
For DeFi users, the same pattern appears every day:
- A wallet asks for approval;
- A hardware device shows a hash, encoded calldata, or a fragment of information only a developer can read;
- The app looks familiar, the process feels routine, and the user signs.
Blind signing begins when cold storage protects the key, while the user approves an instruction they cannot read.
What Is Blind Signing?
Blind signing is the act of approving a transaction without seeing the full transaction intent in human-readable form. When a wallet or dApp lacks clear signing support, users see unreadable hashes or encoded data, making it impossible to verify what they are authorizing.
For simple transfers, users expect to see a recipient address and an amount. DeFi transactions are more complex. A smart contract approval can involve a function call, token permission, spend limit, destination address, swap path, lending action, staking action, or contract upgrade.
The danger appears when the interface says one thing and the payload says another. A front-end, browser extension, or connected phone can display a clean transaction summary while the signing device receives data the user cannot interpret. Once signed, the blockchain executes the instruction exactly as authorized.
Cold storage protects private keys from extraction. Transaction visibility is a separate security problem.
Why Hardware Wallets Alone Cannot Solve Every DeFi Approval
Hardware wallets became popular because they removed private keys from internet-connected devices. That was the right answer to a major risk: malware, phishing pages, browser attacks, and compromised laptops trying to steal seed phrases or sign directly from hot wallets.
DeFi created a different risk. Users now interact with smart contracts every day. They approve token permissions, bridge assets, swap through routers, deposit into vaults, stake, lend, borrow, claim rewards, and connect to new protocols. Each action can contain complex calldata.
A hardware wallet can keep the key offline and still ask the user to approve an unreadable transaction. The signing environment is secure, but the decision-making process can remain blind.
This is why clear signing became such an important security theme. Clear signing turns transaction data into readable fields, such as function, amount, recipient, token, and protocol.
The challenge, however, is coverage. Clear signing depends on supported wallets, supported dApps, metadata, and implementation across the ecosystem. Developers create JSON metadata for smart contract functions and submit it to a registry, after which compatible wallets can display the transaction in plain language.
DeFi moves quickly. New contracts, routers, protocols, aggregators, and app interfaces appear constantly. Users often leave integrated wallet environments to interact with third-party dApps. At that point, readable signing depends on whether the full path supports it.
The Smartphone Issue
Screenless hardware devices create another issue. If the signing device has no independent screen, the user must verify transaction details on a smartphone or computer. That means the device holding the keys may be separate, but the device explaining the transaction remains connected, updatable, and exposed to phishing or malware.
The Bybit attack showed why this distinction matters. According to Dfns, the malicious UI displayed a routine transfer while changing the transaction data sent for signing. The signer did not need to lose a private key, it only needed to approve the wrong instruction.
This is the blind signing problem: the user cannot make a safe decision when the final signing screen fails to show what the transaction will actually do.
ERA Wallet’s Answer
ERA Wallet draws on the new ecosystem standard and makes sure the signing device shows the user what they are approving before the transaction can be signed.
Its main mechanism is ERA Lens™, an on-device transaction parsing engine. ERA Lens translates complex smart contract calldata into plain language, showing the function, token amounts, and destination addresses involved. If a transaction cannot be decoded or does not match a known interface, ERA Lens stops the signing flow and flags it for manual review.
An ERA Wallet Founder Alexey Devyatkin explained the thinking behind the product this way:
“ERA Lens is a fully offline engine. This means the device acts as your personal “Security Island” because, without any internet connection, no one can alter the data stored on the device. As a result, if the device does not recognize a transaction, it is a strong reason to double-check it in order to avoid signing a malicious transaction.”
Air-Gapped Signing With Verifiable Payloads
ERA Wallet also uses a QR-only air-gapped signing model. The device signs without Bluetooth, Wi-Fi, or cables and is built on the open EIP- 4527 protocol. ERA says this lets users verify what data the device sends instead of relying on closed APIs or proprietary bridges.
EIP-4527 itself describes a QR code data transmission protocol between wallets and offline signers. The standard says QR transmission offers transparency because users can decode the data with tools, and it also notes that USB and Bluetooth carry a larger attack surface than QR codes.
This gives ERA two separate security layers:
- The first is physical and architectural, where the device signs offline through QR communication;
- The second is interpretive, where ERA Lens reads the transaction payload before the user approves it.
For DeFi users, both sides are important. Air-gapping reduces connectivity exposure. On-device decoding improves the approval decision.
Recovery Without a Paper Seed Phrase
ERA also replaces the classic paper seed backup with encrypted NFC Recovery Cards. The Recovery Card stores seed phrase backup data in encrypted form, uses PIN protection with limited attempts, and is built around a durable chip designed to protect information for more than 50 years. The card is also described as dustproof and waterproof, with support for single and multi-share backups.
Indeed, seed phrase management remains one of crypto’s weakest user habits. Paper can be lost, photographed, copied, damaged, or stored carelessly. ERA’s approach keeps recovery physical while removing the need to write a seed phrase on paper.
The device also supports up to 10 independent wallets, each with its own seed phrase and optional passphrase. For active users, that allows separation between long-term holdings, DeFi activity, testing wallets, business funds, and higher-risk interactions.
The Hardware Wallet Problem Has Changed
The first era of hardware wallets focused on custody. However, DeFi changed the threat model and the current question regards approval quality.
The EF’s Clear Signing announcement confirms this. Readable transaction approvals are becoming a baseline requirement for safe self-custody as users interact with smart contracts, routers, bridges, staking platforms, lending markets, and multi-signature workflows.
ERA Wallet’s bet is that the next phase of self-custody will be defined by transaction visibility. Keys need protection and approvals need context.
For DeFi users, that may become the more important question before every signature: can I actually read what I am about to sign?
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