Quantum computing
Quantum entanglement
A correlation between quantum systems such that the state of one cannot be described independently of the other, regardless of distance. It is a resource for quantum algorithms and for quantum key distribution.
Related terms
Superposition
The property that lets a quantum system hold a combination of states at once. Superposition alone does not make quantum computers fast — the speedups come from interference that amplifies correct answers.
Quantum key distribution
A method of exchanging keys using quantum physics, where eavesdropping disturbs the transmission detectably. QKD needs dedicated hardware and links, and is not a substitute for post-quantum cryptography — the NSA does not recommend it for national-security systems.