Zach Herbert explains Foundation’s QuantumLink, a post-quantum Bluetooth bet for hardware wallets
Foundation Devices has introduced QuantumLink, a secure Bluetooth protocol for its Passport Prime hardware wallet, enabling real-time connectivity while maintaining security against quantum computing threats.
Foundation Devices, known for its air-gapped security approach, is now embracing Bluetooth connectivity through QuantumLink, a secure protocol for its Passport Prime hardware wallet. The technology aims to provide real-time connectivity while maintaining the isolation that made the company's reputation.
QuantumLink replaces Foundation's previous QR code-based data transfer method with a direct Bluetooth connection to the company's Envoy companion app. The protocol handles onboarding, transaction signing, firmware updates, and syncing, all while maintaining security against both current and future quantum computing threats.
Isolated Bluetooth chip
The Passport Prime uses a dedicated, isolated Bluetooth chip that operates independently from KeyOS, the wallet's primary security processor. While this chip handles the traffic, it is never allowed to read the messages, which are end-to-end encrypted before transmission.
The link handles onboarding, transaction signing, firmware updates and syncing.
Post-quantum cryptography
QuantumLink employs a two-part cryptographic approach. CRYSTALS-Kyber handles key exchange, while ChaCha20-Poly1305 encrypts the actual messages. Kyber serves as the post-quantum component, designed to remain secure against quantum computers.
The pairing process adds another security layer by exchanging public keys via QR code before any Bluetooth traffic flows. This ensures the Bluetooth chip never sees plaintext data, even if compromised. For security purists, Passport Prime allows disabling Bluetooth entirely, with fallback options to QR, NFC, or USB.
From QR to quantum resistance
Foundation's evolution from QR-based air-gapping to QuantumLink reflects the company's adaptation to changing security needs. The protocol was developed in collaboration with Blockchain Commons and publicly introduced on January 23, 2025, with the Passport Prime launching on March 26, 2026.
As community discussions focus on Bluetooth vulnerabilities, Foundation must demonstrate that the hardware separation performs as well in practice as it does in theory. The company's founder, Zach Herbert, a Bitcoin advocate since 2013, has been explaining the protocol across multiple platforms to build confidence in this new approach to secure connectivity.
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