Quantum Research Could Threaten Encryption Schemes

New quantum computers implement algorithm capable of cracking most current encryption codes

SEPTEMBER 13, 2007 | 6:15 PM

By Tim Wilson
Site Editor, Dark Reading

Two groups of scientists have separately implemented computing schemes that threaten the assumptions made in modern encryption technology.

Now, we don't pretend to understand the quantum mechanics outlined in the papers filed by researchers at the University of Queensland and by Chao-Yang Lu at China's University of Science and Technology. But here's what we could get out of them:

Many current encryption technologies, such as RSA, rely on the difficulty of computing the prime factors in very large numbers. When cryptologists want to increase the difficulty of encryption, they simply increase the size of the numbers involved, making it harder for any computer to find the solution.

Using an experimental computer based on photonics, the researchers in Australia and China have independently been able to do a full-scale implementation of something called Shor's Algorithm, a non-linear method of factoring composite numbers. Shor's Algorithm breaks many of the rules of linear computing and therefore has no trouble finding the prime factors in any number, no matter how large.

The research shakes the foundation of all types of currently available encryption methods. If the quantum computer can factor any number of any size with equal ease, then, theoretically, no algorithm based on linear computing is safe.

For the moment, enterprise computers seem pretty secure, since you'd have to be a quantum physicist to crack today's codes. However, the findings could force cryptographers and vendors to rethink their current assumptions about the capabilities of computers -- and therefore radically change future generations of encryption technology.

"The full realization of Shor's algorithm will have a large impact on modern cryptography," the University of Queensland researchers say.

After attempting to read both of these papers, we'll have to take their word for it.