Breez, a lightning service provider and Bitcoin development lab, has integrated passkey authentication into its Breez SDK, enabling developers to build self-custodial Bitcoin wallets without requiring users to manage seed phrases during standard operations. The update addresses a longstanding barrier to Bitcoin adoption while maintaining backward compatibility with existing industry standards.
Removing Onboarding Friction for Self-Custody
The integration leverages the FIDO2 WebAuthn standard, which major technology companies including Apple, Google, and Microsoft have promoted since 2022. Developers using the Breez SDK can now create wallet applications that authenticate users through biometric methods like Face ID or fingerprint scanning—the same security mechanisms users already trust for banking apps and password managers.
Traditional Bitcoin wallets require users to secure a 12-word seed phrase, a process that creates friction during onboarding and continues to deter mainstream adoption of self-custodial solutions. Breez's implementation maintains seed phrase support as an optional backup, allowing users who prefer traditional recovery methods to export a BIP-39 mnemonic while removing this requirement from the initial setup flow.
Technical Implementation Using PRF Extension
The solution utilizes the Pseudo-Random Function (PRF) extension from WebAuthn Level 3 specifications. This extension enables passkeys to generate deterministic cryptographic outputs from specific inputs during authentication, meeting Bitcoin's requirement for reproducible key derivation while keeping private keys secured in device hardware like Apple's Secure Enclave or Android's Titan chip.
Each passkey creates a unique public-private key pair for specific applications, with private keys never leaving the device's secure element. The FIDO Alliance reported over one billion passkey activations as of mid-2025, indicating widespread platform support for the technology.
Recovery options depend on the user's chosen ecosystem. Synced passkeys through iCloud Keychain or Google Password Manager restore automatically on new devices after account recovery. Users concerned about platform lock-in can export standard seed phrases for cross-wallet compatibility.
Implications for Bitcoin Developers
For developers building Lightning Network applications and Bitcoin wallets, this SDK update offers a pathway to reduce onboarding complexity without sacrificing self-custody principles. The reference application Glow demonstrates the implementation, and the technical specification is publicly available for teams integrating the Breez SDK. This development may influence hiring priorities as companies seek developers with expertise in both Bitcoin protocols and modern authentication standards like WebAuthn.
