# Blind signing: why the screen is the only signature you can read

URL: https://www.caijing188.com/blind-signing-screen/
Published: 2026-10-24T09:09:39+08:00 | Updated: 2026-10-27T22:09:55+08:00
Verified: 2026-10-27

## Quick answer
When a wallet cannot decode a payload it shows a hash and asks for approval, and a hash cannot be checked against intent. Ethereum.org's L2 directory put Base at $14.6B of value as of October 2026. The fix is a screen that renders the amount and the full destination, plus a policy of refusing anything else.

## Summary
A signature is a statement only if you can read it, and a hash is a fingerprint rather than a sentence. Blind signing is the fallback a device uses when no decoder matches the payload, which makes it the quiet path around the secure element, the genuine firmware and the PIN. The control is a screen that shows amount, destination and function, and a refusal to sign anything it cannot render.

## Key takeaways
- A digest cannot be compared with an intention, only with another digest
- One blind-signed payload can carry an unlimited approval, an operator approval or a proxy call
- A usable screen answers three questions: how much, to whom, which function
- Strict decoding turns an unreadable request into a stop, at the cost of failed edge cases

## FAQ
Q: Is blind signing ever legitimate?
A: Yes, for payloads you built yourself and can verify against a second source, such as recovery flows, some script paths and some multisig coordination. The problem is the default, where an undecodable request from a website is treated as routine. On a savings device the safe setting is refusal.
Q: Why can a hardware wallet not decode every transaction?
A: Calldata is open ended: any contract can define any function, and new contracts appear faster than firmware updates. Proxies and delegate calls add a layer where the named contract is not the one that executes. Decoders cover common patterns, and the rest falls back to a digest.
Q: Does a bigger or newer device fix this?
A: Not by itself. What matters is whether the firmware carries decoders for the payloads you actually sign and whether the screen has room to show a full address and an amount with the right decimals. A device that renders raw units has moved the arithmetic back to you.