Physicists defend against Trojan-horse quantum hackers

Summary: 

Physicists in the UK have shown how to defend a quantum cryptographic system against Trojan-horse attacks.

By targeting the physical hardware used to encode quantum keys, a Trojan-horse attack can bypass the quantum-measurement-based security of the key itself. New research shows how three simple optical components can reduce the information obtained in this way to essentially zero.

Read more in an article at physicsworld.com or the research paper at Physical Review X.