EIP 4527, an important standard in the Ethereum ecosystem, represents a significant step forward in the field of cryptocurrency wallets and security. It is a protocol that facilitates secure, offline transactions for Ethereum-based tokens. This standard is designed to enhance security by enabling transactions to be signed in an environment that is completely isolated from online threats.

An Abstract and Motivation

The rise of EIP 4527 comes amidst an increasing preference among users for completely offline signers, such as hardware wallets and mobile phones in offline mode, to access their private keys. These offline signers, however, rely on watch-only wallets to prepare data for signing. Currently, methods like QR Code, USB, Bluetooth, and file transfer exist for data transmission between offline signers and watch-only wallets. QR Code stands out with several advantages:

  • Transparency and Security: QR codes allow users to easily decode and verify the data to be signed, enhancing transparency and security compared to USB or Bluetooth.
  • Improved Compatibility: Unlike USB and Bluetooth, QR Codes are less affected by software changes like browser or system upgrades.
  • Enhanced User Experience: Especially on mobile devices, QR Code transmissions provide a smoother experience than other methods.
  • Reduced Attack Surface: QR Codes present a smaller attack surface compared to USB and Bluetooth.

Given these benefits, QR Code data transmission emerges as a superior choice. However, until now, there was no modern standard for how offline signers should work with watch-only wallets or how data should be encoded. EIP 4527 fills this gap by presenting a standard process and protocol for these interactions.


  • Offline signer: A device or application holding user’s private keys without network access.
  • Watch-only wallet: A wallet with network access, interacting with the Ethereum blockchain.

Development and Integration

The creation and integration of EIP 4527 is a testament to the collaborative efforts of several key figures in the blockchain community, including Aaron Chen, Sora Lee, ligi, Dan Miller, AndreasGassmann, xardass, and Lixin Liu. This team's combined expertise led to a standard that significantly enhances the safety of tokens. Notably, imToken added support for EIP 4527 in early December 2023, reflecting its commitment to providing users with secure storage options.

Reference: EIP-4527 on Ethereum.org

QR Code Transparency and Air-Gapped Design

EIP 4527 emphasizes the security-first approach with its 100% air-gapped QR code signage. This eliminates the risk of malware infiltration and enhances the transparency of data transmission. The benefits are manifold:

  • No Physical Connection: The inherent nature of QR codes means transactions can be signed without exposing the AirGap Vault Cold wallet to the internet, maintaining isolation from potentially compromised devices and safeguarding the secret seed phrase.
  • Ease of Use: Generating and scanning QR codes for transaction signing is straightforward and efficient with the AirGap Vault device.
  • Data Verification: Users can verify the data being transferred through QR codes with AirGap Vault’s QR Code verifier, and all firmware updates are open-source, ensuring transparency.

Using a cold wallet like AirGap Vault in conjunction with a watch-only wallet such as imToken is a practice highly recommended for enhanced token security and reduced risk of wallet compromise.


The introduction of EIP 4527 marks a significant milestone in token security, particularly in the realm of offline transactions. This standard not only streamlines the process of signing transactions securely but also paves the way for more transparent and user-friendly interactions between offline signers and watch-only wallets.

How to get started:

One of the easiest ways to get started is imToken in combination with the AirGap Vault. imToken offers fantastic usability and AirGap Vault can be accessed by everybody for free. Find the step by step guide here: https://support.airgap.it/guides/imTOKEN/

As the blockchain technology continues to evolve, such innovations play a crucial role in ensuring the safety and integrity of token access, with a growing list of supported solutions demonstrating the industry's commitment to this endeavor.