Your secrets are safe with quasar encryption

Sean McGrath sean at
Wed Mar 29 21:20:33 EST 2006

Your secrets are safe with quasar encryption

     * 16:00 29 March 2006
     * news service
     * Will Knight

Intergalactic radio signals from quasars could emerge as an exotic but 
effective new tool for securing terrestrial communications against 

Japanese scientists have come up with a method for encrypting messages 
using the distant astronomical objects, which emit radio waves and are 
thought to be powered by black holes.

Ken Umeno and colleagues at the National Institute of Information and 
Communications Technology in Tokyo propose using the powerful radio 
signals emitted by quasars to lock and unlock digital communications in 
a secure fashion.

The researchers believe quasars could make an ideal cryptographic tool 
because the strength and frequency of the radio pulses they emit is 
impossible to predict. "Quasar-based cryptography is based on a physical 
fact that such a space signal is random and has a very broad frequency 
spectrum," Umeno told New Scientist.
One-time pad

Randomness provides a simple means of high-security information 
encryption, providing two communicating parties have access to the same 
source of random information. For example, a randomly generated 
"one-time pad" shared by two parties can be used to encrypt and decrypt 
a message by simply transposing each individual bit of a message for 
bits on the pad.

Genuine randomness is hard to generate artificially and the 
“pseudo-randomness” which most computers use is unsuitable for use in 
cryptography as patterns will be revealed over time. In addition, it is 
also tricky for two parties to share a source of randomness securely.

Umeno and his colleagues suggest using an agreed quasar radio signal to 
add randomness to a stream cipher - a method of encrypting information 
at high speed.

Each communicating party would only need to know which quasar to monitor 
and when to start in order to encrypt and decrypt a message. Without 
knowing the target quasar and time an eavesdropper should be unable to 
decrypt the message.

Umeno believes astronomical cryptography could appeal to anyone who 
requires high-security communications. He adds 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.

"Concerning potential users, I suggest international financial 
institutions, governments and embassies," Umeno says.

The researchers used quasar signals collected by Very Long Baseline 
Interferometry antenna at the institute to encrypt messages and have 
filed two patents covering quasar-based cryptography: one for locking 
and unlocking messages and another for generating digital signatures 
that can be used to match messages or files to a person.

However, some cryptography researchers question the need for such an 
unusual means of securing messages.

"This is interesting research, but there's no reason for anyone to use 
it in a practical application," says Bruce Schneier of Counterpane 
Security. "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 

Markus Kuhn from the University of Cambridge, UK, adds that the physical 
set-up could have potential weaknesses. "It is easy to play tricks with 
reception antennas," he says. For example, he suggests that an attacker 
could mimic a radio signal and "gain a lot of control over the signal 
that the receiver can see."

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     * Let chaos keep your secrets safe
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     * National Institute of Information and Communications Technology
     * Quasar Encryption patent
     * Quasar Authentication patent

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