Japanese tune into quasar encryption

Randomness makes for secure comms

Japanese scientists are proposing the use of random radio pulses emitted by quasars as "one time pads" for the encryption of sensitive messages, New Scientist reports.

Ken Umeno and his chums at Tokyo's National Institute of Information and Communications Technology reckon quasars could be useful in cryptography because "the strength and frequency of the radio pulses they emit is impossible to predict" - thereby making them truly random in contrast to computer-generated "pseudo-randomness" in which patterns will inevitably be revealed over time.

Umeno told New Scientist: "Quasar-based cryptography is based on a physical fact that such a space signal is random and has a very broad frequency spectrum."

Umeno's team proposes that the two parties wishing to encrypt - and subsequently decrypt - use "an agreed quasar radio signal to add randomness to a stream cipher - a method of encrypting information at high speed". Knowing which quasar to monitor and when would be the only information required to enable the secure communication. A third party without this knowledge would find it impossible to decipher the transmission.

Umeno cites international financial institutions, governments and embassies as possible users for the system. The advantages are, he says, that the method "does not require a large radio antenna or that the communicating parties be located in the same hemisphere, as radio signals can be broadcast over the internet at high speed".

The possible pitfalls? Markus Kuhn of the University of Cambridge noted: "It is easy to play tricks with reception antennas...an attacker could mimic a radio signal and gain a lot of control over the signal that the receiver can see."

Bruce Schneier of Counterpane Security chipped in: "This is interesting research, but there's no reason for anyone to use it in a practical application. Furthermore, this is a brand new idea. Why would anyone want to use something new and untested when we've already got lots of good cryptography?"

The Japanese researchers collected quasar signals using their own Very Long Baseline Interferometry antenna. They've filed two patents: one covering encryption and decryption of messages and a second "for generating digital signatures that can be used to match messages or files to a person". ®