Transaction Check: Proactive Security for Ethereum Transactions

Before You Dive In:

—  Transaction Check analyzes Ethereum transactions for potential threats before you sign them, offering an additional layer of protection for your digital assets.

—  While Clear Signing ensures you understand what you’re signing, Transaction Check adds a proactive dimension by identifying potential threats before you sign, creating a comprehensive security approach.

—  Together, these complementary features represent Ledger’s commitment to comprehensive security.

Crypto’s Evolving Security Challenge

For a decade, Ledger has been at the forefront of digital asset security, pioneering a comprehensive approach that integrates hardware and software, and delivers a highly accessible user experience without compromising on security. 

As the industry-leading hardware solution featuring a secure screen, Ledger devices allow you to trust the transaction details you see, empowering users to make the most out of their crypto experience. We frame our approach to securing users against threats as ‘Security at Ease’ vs ‘Security in Use’.

Security at Rest vs Security in Use

Ledger has protected users from hacks for over a decade thanks to our robust security model designed to guard against physical and remote attacks.

1. Secure Element: This is the heart of Ledger’s security. It’s a dedicated chip within our devices that keeps your private keys offline, far away from any hacker’s reach.
2. Operating System (OS): Ledger’s device OS is purpose-built to be immune to malware and attacks, implementing hardware and software isolation to provide an additional layer of protection.
3. Secure Screen: The device screen you use to verify transactions is fully isolated and tamper-proof. It’s not connected to the internet, so there’s no risk of someone hijacking your transaction approvals.

While our infrastructure safeguards your digital assets when a Ledger device is at rest, today the greatest risks emerge when the device is in use. Security in use was simple when Bitcoin was the only game in town. Now, with the rise of smart contracts and complex dApps we’ve  seen a corresponding increase in sophisticated threats that exploit human error to blind sign malicious transactions) changing the challenge of digital asset security.

To get a sense of scale, the FBI’s Internet Crime Complaint Center, or IC3, recently reported that Americans lost $9.3bn to crypto crime in 2024 alone, increasing 66% from the previous year.

We can’t fully eliminate human error, but we can design around it. That’s why we’re enhancing the user experience to provide better clarity at the point of transaction. Clear Signing was the first step. Transaction Check is the next.

What is Transaction Check?

Transaction Check is a security feature that leverages transaction simulations, machine learning, and real-time threat detection to validate transactions before they are signed. Think of it as an antivirus for your 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.

With Transaction Check, you gain the ability to simulate transactions before authorizing them, empowering you to make informed decisions based on concrete results rather than blind trust.

Transaction Check represents a fundamental shift in crypto security, from reactive verification to proactive protection. It’s not just about understanding what you’re signing, but about understanding and anticipating potential consequences before you make transactions. 

Importantly, when this transaction happens on a secure device with Clear Signing, it prevents the scenario where attackers swap in a malicious transaction after a legitimate transaction gets checked (as happened in the ByBit hack).  

In an ecosystem where security threats are constantly evolving, adopting a proactive mindset is essential. Transaction Check embodies this philosophy, allowing you to anticipate and prevent potential threats before they materialize.

How Transaction Check Works

Transaction Check employs advanced blockchain simulation technology to analyze transaction outcomes before you sign. When a user initiates an EVM transaction in Ledger Live, there will be an option to enable Transaction Check. If enabled, the unsigned transaction is sent securely from Ledger Live to independent simulation providers.

These providers run comprehensive simulations leveraging blockchain state, mempool data, prediction models, historical information, and community insights. They issue transaction assessment reports. These reports are authenticated by the simulation providers and cryptographically associated with the transaction. 

The results are then transmitted to your Ledger device, which verifies that the report assessment comes from the trusted simulation providers and matches the transaction to be signed. 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.

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.

Transaction Check & Clear Signing: Complementary Security Pillars

It’s crucial to understand that Transaction Check is not a replacement for Clear Signing. Instead, they are complementary security features that work in tandem to provide comprehensive protection.

Clear Signing focuses on transparency and verification by ensuring that you can see and understand exactly what you’re signing. It translates complex transaction details – from the blockchain – into human-readable form, eliminating the dangers of blind signing. Clear Signing is factual and deterministic: your transaction is either Clear Signed and predictable, or it’s blind signed.

Transaction Check, on the other hand, emphasizes proactive analysis and threat detection. It uses simulation to predict potential outcomes and identify risks before you sign. Transaction Check is probabilistic in nature, meaning it assesses the likelihood of various risks based on available data.

If you want to send Ethereum to a malicious address, clear signing will display the amount and the address, transaction check will tell you that this transaction is risky.

On the other hand, if you’re about to sign a swap of 100 ETH against 1 USD on Uniswap, Transaction Check won’t flag any risk, while Clear Signing will show you the actual swap you’re about to sign.

Together, these features create a security paradigm that addresses both transparency and risk assessment; whereas Clear Signing makes sure you understand what you’re signing when you sign it, Transaction Check warns you ahead of time if what you’re signing is potentially dangerous.

By implementing both, Ledger provides unprecedented security for your digital assets at every stage of the transaction process.

Know Before You Sign

Transaction Check is your Ledger device’s proactive security shield. Now you can analyze transactions before you sign, detect potential threats, and gain clarity on what you’re approving. This is what security in use feels like—unrivaled security, backed by Ledger’s commitment to user protection.

As the digital asset ecosystem continues to evolve, so too will our security features. In the near term, Transaction Check is available for Ledger Flex and Ledger Stax on EVM transactions, but we’re committed to expanding its capabilities across additional blockchains and device types.

As we continue to innovate in the realm of digital asset security, our focus remains on empowering users with the tools they need to navigate the crypto landscape safely and confidently. Transaction Check and Clear Signing represent two sides of the same coin, working together to create the most secure environment possible for your digital assets.

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Authored by Charles Guillemet, Chief Technology Officer