In a pivotal step toward reinforcing cybersecurity, a quantum-resistant FIDO2 security key implementation has been introduced as part of OpenSK, an open-source security key firmware.
Developed with collaboration from ETH Zürich, this groundbreaking implementation leverages an innovative ECC/Dilithium hybrid signature schema. The schema integrates ECC’s security against conventional attacks and Dilithium’s quantum resistance, marking a significant advancement in cryptographic defense mechanisms. This pioneering hybrid approach was honored with recognition at the ACNS secure cryptographic implementation workshop.
With the rapid progression of practical quantum computing, the urgency to prepare for its potential security implications has intensified. Traditional public key cryptography, designed for protection against conventional computers, faces vulnerability against quantum attacks. Encouragingly, the recent standardization of public key quantum-resilient cryptography, including the Dilithium algorithm, has paved the way to secure security keys against quantum threats.
While quantum attacks may remain distant, implementing cryptography at an internet-wide scale is a substantial undertaking, underscoring the significance of early action.
For security keys, the transition is expected to be gradual, with users acquiring new keys as FIDO standardizes post-quantum cryptography and major browser vendors support the new standard. The proposed hybrid implementation combines the well-tested ECDSA signature algorithm with the newly standardized quantum-resistant Dilithium algorithm. This approach balances security with caution, acknowledging the evolving landscape of quantum-resistant algorithms.
On a technical front, the challenge of implementing a compact Dilithium version suitable for constrained security key hardware was met with success through meticulous optimization efforts.
A Rust memory-optimized implementation requiring just 20 KB of memory was developed, while maintaining signature speed within expected security key specifications. As future strides are pursued, the hope is to standardize this implementation within the FIDO2 key specification, supported by major web browsers. This would offer users protection against quantum attacks, a testament to the ongoing commitment to advancing cybersecurity.