Is Blind Signing the same thing as the commonly discussed "Approval Phishing"?
No, but the two frequently overlap. Approval phishing refers to attackers using fake websites or malicious links to trick users into signing a transaction that hands over control of their assets — the core mechanism is deceiving you into signing something you shouldn't. Blind Signing is a more fundamental technical state describing whether, at the moment of signing, the device or the user actually understood what was being signed — regardless of whether that transaction originated from a scam or not.
The connection between the two is this: a blind-signing state is exactly the breeding ground where approval phishing succeeds most easily. If every transaction's actual content could be clearly decoded, the malicious permissions approval phishing tries to smuggle through would have nowhere to hide inside unreadable hex data. Conversely, even without any active phishing attempt, the state of blind signing itself already constitutes a risk on its own, because the user loses the ability to notice, at the moment of signing, that "something about this transaction feels off."
Given that EIP-712 has existed for years, why haven't Hardware Wallet vendors fully phased out Blind Signing?
The core technical constraint is that clear signing requires the device to already have a "descriptor" on hand in order to correctly parse raw data into human-readable fields — and this descriptor has to be built individually for every contract and every transaction structure. New contracts get deployed and new interaction patterns emerge on-chain every single day, and no descriptor database can ever fully keep pace with the actual number of contracts that exist on-chain. When a device encounters a contract not covered in its database, falling back to Blind Signing is its only option.
Another real-world factor is commercial and timeline pressure: fully supporting clear signing requires coordination across wallet vendors, application developers, and standards bodies alike, and if any single party falls behind, what users actually experience remains a blind-signing interface. This is exactly why the industry has recently begun pushing standards like ERC-7730 — a "structured data clear signing format" — attempting to standardize and decentralize the process of generating and verifying descriptors, so more contracts can be covered under clear signing faster. But this remains an ongoing, unresolved industry-wide effort.
Faced with a transaction requiring Blind Signing, what can an ordinary user actually do in the moment to reduce risk?
The first step is recognizing whether the urgency around this transaction has been deliberately manufactured — most blind-signing risk plays out in situations where users are rushing to complete an action, like a limited drop selling out or an Airdrop deadline about to close. Simply slowing down is itself the most basic line of defense. Second, transaction simulation tools — now built into most mainstream software wallets like MetaMask and Rabby — let you preview what will actually happen to your wallet's holdings if you sign, before you formally sign anything. This simulation runs through an independent computation path separate from the signing interface itself, which to some degree can catch a mismatch between what the screen displays and what would actually execute.
Third, for especially large transactions or ones involving unfamiliar contracts, it's worth copying the transaction's raw call data into a blockchain explorer's decoder (like Etherscan) — a source completely independent of the wallet interface — and cross-checking it there. Only when all three channels (the wallet's display, the simulation tool, and the blockchain explorer's decode) agree with each other is there real reason to trust that the transaction does what you expect. Relying on a single screen's display alone to make a signing decision is always the riskiest approach.
If I only occasionally use my Hardware Wallet for small transactions, is it worth learning all this?
Yes, and the reason has less to do with transaction size than you might think. The most dangerous aspect of blind-signing risk isn't the dollar amount of any single transaction — it's the nature of the "approval" action itself. Many DeFi operations don't ask for a one-time transfer of a fixed amount; they ask you to authorize a contract to move an unlimited amount of a given Token from your wallet, indefinitely, at any point in the future. Once that kind of approval is signed, even if you only intended to test a new protocol with a small amount, failing to notice an unlimited-approval clause buried in a blind-signing screen could hand over your wallet's entire control over that token.
A more practical reason is that learning to recognize blind-signing risk is a Skill you learn once and carry forever — you don't need to relearn it before every single transaction. All it takes is building one consistent habit: pause the moment you see raw hex data, run it through a transaction simulation tool, and for "approve"-type operations in particular, double-check whether the approval limit is unlimited. Once that habit is in place, whether your next transaction involves ten dollars or a hundred thousand, the same process reduces the risk — rather than having to cram this knowledge in a hurry the day you happen to be moving a much larger amount.
You just bought a Hardware Wallet and feel like your assets are finally safe. You click "approve" on some DeFi platform, and your hardware wallet screen shows a long string of hex: 0x6a76120200000000000000000000000087870bca3f3fd6335c3f4ce8.... You have no idea what it means, but you hit confirm anyway — because the interface says this is routine, and the wallet itself really is secure, with no cryptographic flaws whatsoever. This is precisely the situation the three signers in the Bybit incident faced, and it's a routine nearly every hardware wallet user repeats every single day: hitting confirm on a string of data they cannot read. This action has a name — it's called Blind Signing.
Blind signing refers to a hardware wallet signing a raw hexadecimal string or hash without sufficient context — the device itself has no way to decode that string back into human-readable information about who you're authorizing, how much you're moving, or what operation you're actually performing. Ethereum's early eth_sign method was the original prototype of this pattern: everything a user faced, from start to finish, was just a hash whose meaning couldn't be verified, and the hardware device would faithfully sign that hash without any knowledge of what transaction actually stood behind it. The user had no choice but to trust whatever the software interface on the other end of the screen told them. That's exactly the problem: the real work of figuring out what a transaction actually does gets outsourced entirely to a software layer outside the hardware device itself — and that layer is precisely what attackers target most often.
To address this, the Ethereum community proposed EIP-712 in 2017, defining a standard for "structured data signing" that lets developers tag transaction data with field names and types in a fixed format, giving wallet devices a chance to parse the data into human-readable fields — "Amount: 100 USDC," "Recipient: 0x1234...," and so on. Hardware wallet vendors built three signing tiers on top of this: blind signing (raw data, entirely unreadable), transparent signing (full technical fields displayed, but packed with details most users can't parse), and clear signing (the device parses and clearly displays the transaction's actual intent). The catch is that clear signing requires the device to already have a "descriptor" for a given contract or transaction type in order to parse it correctly — facing a newly deployed contract, a complex nested operation (like the MultiSend batch transactions common in Safe multisig wallets), or a protocol not yet catalogued in any descriptor database, the device often has no choice but to fall back to blind signing. That's exactly why, years after EIP-712 shipped, blind signing has never actually disappeared from many real-world usage scenarios.
Even more worth being alert to: even when a device supports clear signing and the screen displays clean, readable fields, that still doesn't guarantee what you're seeing is true. A hardware device remains a machine running software, and whatever "parsed result" it displays on screen is computed by some piece of code — if the software responsible for generating that display has itself been compromised, what the device faithfully displays becomes a tampered illusion. This is precisely the most fundamental lesson of the Bybit incident: the problem wasn't that the signers couldn't read raw data and signed blind — it's that the "clear, readable screen" they saw had itself been meticulously fabricated by attackers. A decoded screen narrows the risk of signing something unreadable, but it does not establish that the screen is telling the truth.
It's worth noting that this risk hasn't gone unnoticed by the industry — some wallet vendors have had related security issues reported and took well over a year to fully fix them; some mainstream software wallets took several months between announcing the removal of a known-risky signing method and actually finishing that removal. By contrast, after the Bybit incident, the Safe team rolled out response measures addressing the risks exposed by that event within an extremely short window. This contrast makes one thing clear: many of these risks were already known within the industry long before they made headlines — what actually drives the speed of a fix is usually the pressure of a major loss having already occurred, not the moment the risk was first discovered.
If you use a hardware wallet, next time you're about to sign a transaction, check whether your screen shows fully readable fields — amount, recipient, operation type — or a string of hex you can't interpret. The latter is a clear blind-signing red flag, especially for larger transactions or unfamiliar contracts, and it's worth pausing to independently verify through an official channel or a blockchain explorer. But more importantly, remember the lesson from Bybit: even a clean, readable screen isn't a guarantee, since that "clean, readable" result was also computed by software that could potentially be compromised. The practice that actually reduces risk is using a tool entirely independent of your primary signing interface to re-verify the transaction content for especially large operations — not simply reading whatever text appears on screen and hitting confirm.