NIST has developed a quantum key distribution (QKD) system that generates encryption keys at a record-breaking rate of 1 million bits per second, making it practical for various applications. The system, which cannot be intercepted without detection, uses single photons to create a verifiably secret key. The NIST testbed, which provides a measurement and standards infrastructure for research, testing, and technology development, is being used to develop data-handling techniques associated with this type of encryption. The keys are generated by transmitting single photons that are polarized in one of four possible ways, and an eavesdropper reading the transmission causes detectable changes at the receiver. The NIST team has packaged data-handling electronics operating in the gigahertz range in a pair of programmable printed circuit boards that plug into standard PCs. Photon losses caused by imperfections in the photon sources and detectors, optics, and procedures reduce the key generation rate, but the 1 million bps rate makes QKD practical for a variety of new applications.
Keywords: Photons, Quantum Key Distribution, Encryption, Key Generation, Quantum Mechanics
