Toshiba plans to apply its break-through to the development of ultra-secure video conferencing and CCTV systems. The quantum video link enhances the security of communication systems by encrypting each frame with a unique digital key. The secrecy of each key is guaranteed by quantum cryptography, the most secure key distribution technique known. A prime advantage of quantum cryptography is that it also allows the key distribution link to be monitored for tapping. Cryptography, the science of information security, is essential to protect electronic business communication and e-commerce. It enables, for example, the confidentiality and identification of users and validation of electronic transactions. All of these applications rely upon digital keys which are shared between legitimate users, but which must be kept secret from everyone else. It is essential therefore to be able to distribute keys between users securely. Furthermore, in order to protect the system from crypto-analysis or key theft, it is important to change the keys regularly. Quantum cryptography allows users on an optical fibre network to refresh their keys frequently in a completely secret way. It takes advantage of the particle-like nature of light. In quantum cryptography, each bit of the key is encoded upon a single light particle (or ‘photon’). The impossibility of faithfully copying this stream of encoded photons ensures that an adversary can never determine the key without leaving detectable traces of their intervention. The encryption of streaming video with quantum keys follows Toshiba’s realization of a quantum key distribution system that can work without interruption. This was achieved using an active stabilization system, which manages and automatically adjusts the hardware to maintain continuous operation. The result is an efficient, easy-to-use system that serves keys for crypto applications and requires no user adjustments. The technology was demonstrated to financial institutions and government representatives in London by scientists working at the Cambridge Research Laboratory of Toshiba Research Europe where the system was developed. Dr Andrew Shields, who leads the Toshiba group developing the system, said, “Corporate networks are increasingly vulnerable to the theft of keys from the desktop, either by hacking, Trojans or fraudulent employees. The Toshiba Quantum Key Server mitigates this risk by allowing frequent key refresh. The Toshiba Quantum Key Server can be used to enhance the security of not just video and speech, but also a wide range of other high bandwidth data communications, ranging from sensitive legal documents to medical and tax records”. Professor Michael Pepper, Managing Director of Toshiba Research Europe Ltd, commented “This new advance extends the range of communications systems whose security can be enhanced using quantum techniques.”