What is blind signing?

Blind signing is when you approve a crypto transaction without being able to read what it does. Your wallet or hardware wallet receives encoded data it cannot interpret, so instead of "swap 100 USDC for ETH" you see a long hash or a generic notice. Ledger's glossary compares this to signing a blank check.

Why does blind signing happen?

Simple transfers are easy for a wallet to display. Interactions with smart contracts, such as swaps, approvals or staking, carry "calldata" that the device must decode. Trezor explains that when the device has no description of that contract, it can only show a hash or "Data Present," leaving you nothing concrete to verify. The details shown on your computer screen could have been altered by malware, phishing or a fake website.

How do you enable blind signing on a Ledger?

Ledger's academy explains that blind signing is disabled by default. To turn it on, open the relevant coin app on your device (for example, Ethereum), go to Settings and enable Blind signing, then accept the warning. Ledger says you will mainly need this for apps outside its own ecosystem, since apps integrated into Ledger Wallet use clear signing and a transaction-risk scan by default.

If you do enable it, Ledger suggests using a separate "burner" account that holds only the funds needed, confirming you are on the genuine website, sticking to well-known apps, and ignoring links sent in social media messages.

Is blind signing safe?

It carries real risk. Ledger's glossary says you have to trust that the app is honest and your computer is free of malware. A malicious transaction can hide behind unreadable data and grant a contract unlimited access to your tokens or send funds somewhere you did not intend. Ledger links blind signing to billions of dollars in losses from malicious contract exploits. This is a common way wallet drainers work.

What is the difference between clear signing and blind signing?

Clear signing turns the encoded transaction into plain language on the device's own screen, so what you see is what you sign. It is defined by ERC-7730, an open Ethereum standard: projects publish files that describe their contract functions, and compatible wallets use them to show the action, tokens, amounts and recipient.

As of October 2026, Ledger's developer portal says it handed stewardship of the clear signing registry to the Ethereum Foundation on May 12, 2026, with Trezor, MetaMask and others also involved. Trezor says its supported devices decode the transaction on the device itself, but if a contract has no published description, the device falls back to blind signing with a warning. So clear signing coverage is growing, but you may still meet both kinds of request in one session. If the decoded details do not match what you expected, do not sign.