62-mile quantum connection extends un-hackable internet range by 100x

Researchers led by Bo-Wei Lu have successfully demonstrated device-independent quantum key distribution (DI-QKD) over 62 miles (100 kilometers) of optical fiber, extending the secure range of this encryption method by approximately 100 times compared to previous records. DI-QKD enhances security by relying on the fundamental laws of physics through Bell inequality violations, rather than trusting the internal workings of hardware devices, which may be compromised. This approach ensures provably secure communication even when devices come from untrusted sources, addressing vulnerabilities posed by future quantum computers. Achieving DI-QKD over such a long distance posed significant technical challenges, including maintaining high-quality entanglement despite signal loss and environmental interference in optical fibers. The team overcame these obstacles by employing advanced techniques such as single-photon interference, quantum frequency conversion to low-loss telecom wavelengths, and noise-suppressed photon emission. Their results demonstrated secure quantum key generation at 11 km with finite data and indicated positive key rates are achievable even at 100 km, making