Transaction Check

May 19, 2025 | Updated May 19, 2025

Transaction Check is a security feature for Ledger devices that simulates crypto transactions, identifying potential threats before you sign.

Transaction Check is a security feature for Ledger devices that simulates crypto transactions, identifying potential threats before you sign.

How Transaction Check Works

Transaction Check operates like an antivirus firewall but for crypto interactions: scanning and analyzing Ethereum Virtual Machine (EVM) transactions before you sign them, identifying potential threats, and providing clear insights to help you make informed decisions.

The process of using Transaction Check is as follows:

The option to enable Transaction Check pops up when an EVM transaction is initiated in Ledger Live
The unsigned transaction is sent securely from Ledger Live to independent simulation providers, which run comprehensive simulations leveraging blockchain state, mempool data, prediction models, historical information, and community insights.
The simulation providers issue transaction assessment reports, which are authenticated by the simulation providers and cryptographically associated with the transaction.
These results are then transmitted to the user’s Ledger device, which verifies that the report assessment comes from the trusted simulation providers and matches the transaction to be signed.
Based on these simulations, Transaction Check provides a clear assessment, including the type of transaction, an indication of any potential risk, the name of the simulation provider, and this risk assessment is securely displayed to the user on their device.
Finally, the user decides if they want to sign this transaction, taking into account the risk assessment report. If they want more info, they can scan a QR code and have more details on the risk assessment report for this specific transaction.

Crucially, this process is specifically designed to resist man-in-the-middle attacks. The secure element has cryptographic guarantees that the risk assessment report is legitimate.

Clear Signing vs Transaction Check

While both Clear Signing and Transaction Check enhance security for Ledger users, they serve different yet complementary purposes.

Clear Signing focuses on transaction transparency, displaying transaction details in a human-readable format on your Ledger device screen, allowing you to know exactly what you’re signing. Transaction Check, on the other hand, goes beyond displaying information to actively simulating transaction outcomes and identifying potential risks based on provider activity and other details.

When used together, these features provide comprehensive protection: Clear Signing ensures you can verify the transaction details are legitimate, while Transaction Check proactively analyzes potential security threats and consequences of the transaction.

For example, if you were to send some crypto, Clear Signing would simply show you the specific address you’re about to send to, whereas Transaction Check could tell you if that specific address belongs to an attacker.