How Ledger eliminated multisig blind signing with the 1inch Swap API

Ledger integrated the 1inch Swap API into its new multisig security layer to eliminate blind signing and deliver secure, best-rate treasury swaps for on-chain organizations.

For years, multisig wallets have been the backbone of on-chain treasury management for DAOs, funds, enterprises and DeFi teams. But despite their reputation for security, multisig systems have lived with one fundamental vulnerability: blind signing. 

According to Sebastien Badault, EVP of Enterprise at Ledger, blind signing had become “a silent, critical flaw accepted as ‘the cost of doing business’ for too long.”

For an organization managing large treasuries, relying on simulations on a computer - while the actual signature happens on a separate, potentially compromised device — was simply not sufficient. “True security is only achieved when the final verification happens on a trusted, isolated hardware device with a Secured Display,” says Badault, adding that Ledger needed a way to guarantee transaction integrity at the moment of signing and maintain efficient treasury operations across multiple chains.

Challenge: safe multisig teams needed secure, reliable swaps

Ledger Enterprise customers depend on multisig accounts for collective asset management. But every multisig operation, including crypto swaps, required signers to approve transactions blind, without seeing full, verified transaction details directly on their Ledger device.

Off-device simulations helped, but they didn’t solve the core issue: the signer still had no cryptographically verified guarantee that the transaction displayed off-device was the same one they were about to authorize.

At the same time, multisig organizations need to move assets efficiently to rebalance portfolios, execute treasury strategies and manage liquidity across networks. Achieving both high security and execution efficiency required a new approach.

Solution: integrating the 1inch Swap API into Ledger Multisig

Ledger’s overhaul of multisig security - Ledger Multisig - introduces clear signing, displaying full transaction details directly on the Ledger device. To support the same high standard for swaps, Ledger chose the 1inch Swap API as its execution layer.

The 1inch Swap API brings several key advantages for a multisig environment:

• Verified swap routes delivered to the device for clear signing
• Deep liquidity aggregation to ensure the best execution price across hundreds of DEXs
• Safe-compatible, multi-chain support
• MEV-resistant execution paths that protect treasury swaps
• No need for blind signing, thanks to structured, readable data via EIP-712

This means Ledger Multisig users can execute swaps with the same security guarantees that the platform applies to governance operations or asset transfers - all through their trusted hardware device.

As Badault explains, Ledger Multisig “is the experience and security layer that brings world-class Clear Signing Safe accounts.” By integrating the 1inch Swap API, every swap is displayed clearly and verifiably on the secure Ledger screen before approval.

Result: safe, efficient, multi-chain treasury swaps

With the 1inch Swap API powering swaps inside Ledger Multisig, organizations benefit from:

• Eliminated blind signing for all swap operations
• Accurate, trusted clear signing for complex contract interactions
• Best-rate swap execution via 1inch aggregation tech
• Automated threat detection through Ledger’s Transaction Check
• Zero-migration onboarding - teams can use existing Safe accounts seamlessly

Ledger strengthened the security foundations of multisig accounts while enabling a fast, intuitive treasury workflow.

In addition to bringing swaps to Ledger Multisig, 1inch is also adopting the signing technology to elevate its own security across its own treasury workflows. By utilising Ledger Multisig, 1inch is creating and setting the standard for secure and seamless operations.

A safer future for on-chain organizations

Ledger Multisig sets a new standard for multisig operations, combining world-class hardware signing with trusted swap execution from 1inch. The result: organizations can manage assets, rebalance treasuries and interact with DeFi with clarity, confidence and uncompromising security.

Stay tuned for more case studies on 1inch products!