What you see is what you sign — never blindly approve a transaction again.
The first rule of crypto safety is: Don’t blindly trust, always verify.
Over the years, hardware wallets have proven effective in protecting private keys. However, due to the complexity and unreadability of transaction data, many users still fall victim to phishing scams by blindly signing transactions — mistakenly transferring assets or authorizing malicious contracts, leading to irreversible losses.
These scams are not caused by vulnerabilities in smart contracts, but by users being unable to understand the transaction content or identify risks before signing.
That’s why OneKey created SignGuard — to ensure every user can clearly understand a transaction before signing and identify potential risks before confirming.
What is SignGuard?
SignGuard is OneKey’s exclusive transaction protection system. It operates through collaboration between the OneKey App and hardware devices, fully parsing and presenting transaction details before signing, helping users make safe, informed decisions.
How Does SignGuard Work?
SignGuard is OneKey’s exclusive transaction protection system. The OneKey App and the hardware wallet work together to deliver clear signing preview and real time scam detection. They simulate and preview transaction details before you sign, so you know exactly what will happen.
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1) On the App Side: Clear Signing and Scam Detection
The OneKey App simulates key elements of on-chain transactions, including:
• Smart contract method (transfer, approve, permit, delegatecall)
• Approval amount and target address
• Contract name instead of a confusing address
It also integrates with GoPlus and Blockaid to detect malicious contracts, fake tokens, phishing websites, and suspicious contract methods, providing real time risk warnings before users sign.
2) On the Hardware Side: Offline Clear Signing and Final Confirmation
The hardware wallet simulates the transaction locally. It then shows a trusted, human readable summary on the device screen: the method, the amount and recipient or spender, and the contract name.
Even if the user operates from a compromised computer or browser, they can verify the transaction intent on the independent secure hardware device.
Users must complete the final signature on the hardware device, ensuring true What You See Is What You Sign and a fully verifiable and secure process.
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Why Is SignGuard Critical?
Many users mistakenly believe that using a hardware wallet alone guarantees safety. In reality, it does not.
In actual phishing cases, attackers lure users to fake DApps or phishing sites and trick them into signing seemingly “normal” transactions that may:
Grant full token access to an attacker (approve all)
Approve access to a malicious address (hidden from the UI)
Appear to “claim” an NFT but actually authorize or transfer assets
Most wallets only display vague data like transaction hashes, making it impossible for users to understand what they’re approving — a vulnerability attackers love to exploit.
Blind signing is like signing a blank check without seeing the amount or recipient. Anyone can become a victim.
Not All “Signing Previews” Can Be Trusted
Some wallets claim to support “clear signing” or “transparent previews”, but many only work with certain chains or contracts. Most lack real-time phishing detection, and few can ensure consistent display across both App and hardware screen.
Only OneKey SignGuard offers all of the following:
Feature | Typical Wallets | OneKey SignGuard |
Transaction Parsing | Limited | ✅ Supports major chains & methods |
Phishing Detection | ❌ Not supported | ✅ Real-time alerts (mainstream DApps supported) |
Hardware Display | ❌ Not available | ✅ What You See Is What You Sign |
Note: SignGuard’s support continues to expand. It currently covers Ethereum, BNB Chain, Tron, and most commonly used methods. Some complex or uncommon contract calls are not yet supported.
How to Use SignGuard
Getting started with SignGuard is easy:
Install or update to the latest version of the OneKey App (iOS, Android, or desktop)
Connect your OneKey Pro or OneKey Classic 1S
When you interact with any DApp, approve or transfer, SignGuard automatically activates
The App will show parsed transaction details and risk warnings
After reviewing, complete the signature on your hardware device
Supported networks include Ethereum, BNB Chain, Polygon, Arbitrum, Optimism, Base, Scroll, and more coming soon.
Signing Isn’t the Final Step — It’s the Security Gatekeeper
We used to think that signing a transaction was just a final confirmation step.
But in today’s world of sophisticated scams, signing has become the last line of defense.
SignGuard is not just an add-on — it’s a core security component.
With human-readable transaction previews and real-time risk analysis, SignGuard empowers every user to detect threats and avoid traps, ensuring a truly What You See Is What You Sign experience.
Update your OneKey App and device firmware now to start your safer on-chain journey: