Quantum Leap In Network Security

Posted by: Jennifer L. Schenker on October 14

Researchers in Europe are getting close to commercializing a dramatically different and more secure way of transporting sensitive data sent over networks. Among the first customers will be big phone companies, which are expected to offer the new type of encryption service to banks, corporations, and governments.

The technology, called quantum cryptography, is one of the first computer applications of quantum physics, which is expected to replace today’s binary system of computing, where data is represented in ones and zeros. Sometime between 2015 and 2020, scientists say they hope binary bits will be encoded on particles like photons or electrons. These quantum bits would allow computers simultaneously to perform multiple complex calculations.

Quantum cryptography uses encoded photons to thwart spying. Single photons, which are discrete particles of light, transfer the numeric keys used to encrypt a message. The photons are so delicate that any attempt by a hacker to intercept these photons scrambles their encoding and alerts users that their key is not secret.

This system has a number of advantages over the way things work now. Most system today use very long prime numbers, called keys. Two keys are involved in each encryption: a private key that can be accessed only by the sender, and a public key available to anyone. The two systems work together so that a message scrambled with a public key can only be unscrambled with the private key. Public key systems require that the sender know the recipient's public key to encrypt a message, necessitating the establishment of a global registry of public keys.

Trouble is, given a powerful enough computer it's possible to figure out the private key from the public key. Quantum cryptography does away with the need for a registry--and the use of photons build in an extra degree of security to thwart hacking.

Until now, quantum cryptography has had only limited use. Its low bit rate meant that quantum crypto messages sent over fiber optic cables couldn't travel very far and would only work point-to-point, i.e. with computers directly connected to each other, not those linked by a network.

But that's about to change. On Oct. 8 in Vienna, researchers from across Europe working on a project overseen by the EU-sponsored SECOQC (Development of a Global Network for Secure Communication Based on Quantum Cryptography) demonstrated support of eight users in a network configuration. What's more, on the same day, researchers at Toshiba Research Europe's Cambridge lab announced they had increased the bit rate of quantum key distribution, allowing quantum cryptography to be applied for the first time to optical fiber networks connecting many users.

The Toshiba breakthrough allows a 100-fold increase, to more than one megabit-per-second for a 20 kilometer link, enabling use of the technology on networks with 8,000 users. This brings commercialization much closer, says Andrew Shields, head of the quantum information group at Toshiba's British research laboratory. Phone companies and banks are among those already testing Toshiba's technology.

Eric Domage, an analyst at technology consultancy IDC, says he believes quantum cryptography will offer significant advantages over the current ways of protecting data. But, he stressed, given enough time and computing resources, nothing is uncrackable.