What could quantum physics and Paris Hilton possibly have in common?

The Hilton hotel chain heiress and Hollywood starlet got a bonus 15 minutes of fame a few weeks ago after hackers burrowed their way into her mobile phone, stealing her celebrity contact information and distributing it across the Internet.

Her experience raised an issue few had contemplated before That evil techies bent on doing bad things can unlock the contents of a cellphone, Blackberry or wireless PDA just like any other computer system or network.

It also turned the spotlight on an evolving form of Internet security called quantum cryptography, which is being touted as a far more secure way to stop hackers bent on cracking codes and stealing digital information - too late for Paris but possibly in time for the rest of us.

Based on Einstein's theory that something observed is something changed, the idea is that by sending data by way of photons, or microscopic particles of light, eavesdroppers attempting to see that data automatically change the photons' state.

A quantum cryptosystem, as it's called, has a transmitter and a receiver, which like a straw or a water pipe allows photons to travel back and forth from sender to recipient. For added measure, the data is encrypted before sending. If the photons get from one end to the other without being altered, the message is secure and the recipient can look at it. If they've been altered anywhere along the way, the message has been hacked, can't be deciphered, and must be re-sent.

It is light years ahead of the safeguards most computers and networks currently have in place, which use straight encryption - passwords or random strings of letters and numbers that, when punched in and deciphered correctly, unlock the data.

Quantum encryption, which different universities and research labs around the world are perfecting, and which two companies have already started putting to use, stands up to brute-force calculations that can eventually crack a code and yield a message's contents.

"You cannot look at the message without changing it, effectively changing the key," says Martin Illsley, research director for Accenture Technology Labs in Sophia Antipolis, a technology research park in Southern France. "That is what makes it unbreakable."

Typical encryption uses complex mathematics and a special number, called a key, which allows a message to be encoded so that only the intended recipient can read it.

A key for a typical email or Web page today is 128 bits, or about 40 digits - meaning a hacker would have to get all 40 letters and numbers in the correct combination to break the code.

The theory goes that because there are so many possible keys, an attacker has little chance of finding which key corresponds to the message. Algebra, algorithms and other heavy-duty mathematical equations play a part ensuring the code remains difficult to crack.

Difficult, but not impossible. With each sophisticated sequence comes the ability, eventually, using ever more sophisticated computer programs and technology, to figure out a way to unlock it, meaning data can never truly be completely safe and secure.

Just ask Paris Hilton.

Researchers already know that quantum computing, still 10 to 15 years away, holds the potential to slice through regular encryption security like butter.

Who else needs quantum physics to protect data? Governments are keen, which is why they're backing universities researching the area. Banks, healthcare providers and public utilities (think nuclear) are also candidates, as are telecom companies (think Paris Hilton's cellphone network provider).

Two companies - Geneva-based id Quantique and New York-based MagiQ - have so far unveiled commercial quantum key systems that could be put to use today.

id Quantique is a spinoff from the University of Geneva. One of its first customers was the Swiss government, now using the technology to ensure electronic security for elections, since the Swiss vote a lot and online.

MagiQ (pronounced Magic), founded by Wall Street magnate Bob Gelfond, has scientific collaborators from the University of Toronto, the University of Calgary, the Perimeter Institute in Waterloo, and the University of California at Los Angeles, among others, on its team.

Corporations like AT&T, Bell Labs, Hewlett-Packard, IBM, Microsoft and NEC are also busy researching commercial applications for quantum information processing, as are Universities like MIT, Caltech, Stanford and Princeton.

DARPA, the U.S. Defence Advanced Research Projects Agency, allocated $100 million (U.S.) over five years for QIP research.

Realistically, average consumers won't see quantum cryptography until long after quantum computing replaces today's computing technology.

By then its claim to being unbreakable could already be broken.

"As you would expect in the security research environment, there's a yin and there's a yang," says Charles Kolodgy, a director with technology research firm IDC. "There are people out there already saying we'll be able to break this eventually. It's what keeps the circle interesting."

There's another element no computer can ever protect us from human error.

An Atlanta-based data collection company called ChoicePoint has fessed up that detailed consumer information it holds in its database - names, addresses, social security numbers and credit information - got into the wrong hands.

Quantum cryptology, photons, neutrons, or any other form of scientific security wizardry wouldn't have helped ChoicePoint, now facing a potential class-action lawsuit from the angry people whose information it says "may" have been compromised.

Which provides another lesson No science or technology in the world will ever be able to prevent the age-old hazard of being duped.