eth_sign Eyewash: Principles, Techniques, and Countermeasures

Recently, the eth_sign blind signing eyewash has frequently appeared, and many users unknowingly signed seemingly harmless eth_sign signatures on certain websites, resulting in asset losses in their wallets. To help everyone better understand the operational mechanism of this eyewash, it is necessary to first explain the essence of the eth_sign signature.

Introduction to eth_sign Signing

eth_sign is a widely used signing method in the Ethereum ecosystem that allows users to sign messages using their private keys. This signing mechanism plays a key role in blockchain transactions as it can prove that a specific account is the initiator of the transaction. In simple terms, this is similar to signing a paper document to indicate that you agree with or support the content of the document.

However, there is an easily overlooked issue in the use of eth_sign, known as "blind signing." When users sign messages with eth_sign, they often cannot fully understand what content they are signing, nor can they verify the specific meaning represented by the signature in reverse. This is because the input to eth_sign is a raw string, not a human-readable format. It is like signing a contract written in a foreign language, which is why it is referred to as "blind signing."

Common Eyewash Techniques

After understanding the concepts of eth_sign signatures and blind signatures, we can further explore the potential risks of eth_sign and how to prevent such blind signature eyewash.

Since eth_sign can be used to sign various types of messages, including transactions and smart contract instructions, malicious third parties may lure users into signing a message that they do not fully understand, resulting in assets being transferred to the scammers' accounts. More seriously, scammers may provide a seemingly harmless message for the user to sign, but in reality, this message could be an operational instruction, and once the user signs it, the assets will be transferred to the scammers' accounts.

Preventive Measures

In the face of this situation, how should we protect ourselves? In response to such eyewash behaviors, a well-known wallet has upgraded its risk control system in the new version. When users access third-party DApps and call eth_sign to sign messages, the wallet will pop up a risk warning window, informing users that the current transaction may have potential risks and initiating a 15-second countdown cooling period. This setup aims to give users enough time to assess the necessity and safety of the signing operation.

Security Recommendations

Security experts remind everyone:

1. Be highly vigilant regarding all requests that require eth_sign signatures, especially those from unknown or untrusted sources. If you have any doubts about the authenticity or purpose of the request, do not sign lightly.

2. Ensure that the messages or transaction requests you handle come from trusted channels, such as official websites, official social media, or verified communication channels. Never trust links, emails, or private messages from unknown sources.

By staying vigilant and taking appropriate security measures, we can effectively reduce the risk of becoming victims of the eth_sign eyewash. In the blockchain world, security awareness and a cautious attitude are key to protecting one's assets.