Unbreakable cryptographic communication made possible

TOKYO - Mitsubishi Electric Corp. and the Research Institute for Electronic Science, Hokkaido University, announced today the success of their quantum cryptographic experimental system.

This is the first report in Japan concerning quantum cryptosystem experiments for absolute security against cryptanalysis.

Quantum cryptography provides secure key distribution and cryptographic communication owing to the instant detection of eavesdroppers on communication channels.

Quantum cryptography is based on the fundamental physical law that observation by eavesdroppers inevitably affects the quantum system and the information of the system before observation, making the information incomplete.

That is, once communication content is tapped on the channel, the content itself changes irreversibly. The eavesdropped content, then, becomes meaningless and the legitimate recipient can detect the eavesdropper by the change in content. Thus the legitimate initiator and recipient are able to take measures against eavesdropping.

Mitsubishi has already developed linear cryptanalysis, the block cipher MISTY, which has provable security, and public key cryptosystems such as elliptic curve cryptography.

Recently KASUMI, based on the design of MISTY, has been adopted as the global standard algorithm for use in next-generation cellular phones (W-CDMA).

Mitsubishi Electric will take the next step and apply quantum cryptography to installed fibers for general telecommunication use and make the bit rate (transmission speed) higher.