Neither of these techniques actually breaks the fundamental principles on which quantum cryptography is based.

ECONOMIST: Secure cryptography is only as safe as its weakest link

Such a photon counter is essential if quantum cryptography is to work, because it will allow what are known as quantum repeaters to be built.

ECONOMIST: Quantum information technology

Quantum cryptography: The end of the code war?

ECONOMIST: Napoleon and Wellington

They stole information from a research version of a system made by ID Quantique, a Swiss firm that is trying to commercialise quantum cryptography, by taking advantage of synchronisation signals that pass between Alice and Bob.

ECONOMIST: Secure cryptography is only as safe as its weakest link

In The Code Book: The Evolution of Secrecy from Mary, Queen of Scots, to Quantum Cryptography, due out soon from Doubleday, British author Simon Singh traces the evolution of the centuries-old battle between code writers and code breakers.

FORBES: I've got a secret

New quantum computers have the potential to be millions of times faster than even our most powerful supercomputers today, quantum cryptography will usher in a new era of super-secure transactions and quantum storage will achieve unparalleled density.

FORBES: The Next Digital Paradigm

That does not matter for classical telecoms, but matters very much for quantum cryptography, which relies on the fact that no eavesdropper can intercept the message without changing those quantum states, and thus giving away the fact that he is on the line.

ECONOMIST: Quantum information technology