QUANTUM THEORY WITH INFORMATION ASSURANCE

Quantum Theory with Information Assurance

Quantum Theory with Information Assurance

Abstract

Quantum information processing” is a new and dynamic research field at the crossroads of quantum physics and computer science. It looks at the consequence of encoding digital bits - the elementary units of information - on quantum objects. In order to emphasize this difference, a digital bit is called a quantum bit or a "qubit" in this context. With the miniaturization of microprocessors, which will reach the quantum limit in the next fifteen to twenty years, this new field will necessarily gain prominence.

Its ultimate goal is the development of a fully quantum computer, possessing massively parallel processing capabilities. Cryptography is the art of rendering information exchanged between two parties unintelligible to any unauthorized person. Although it is an old science, its scope of applications remained mainly restricted to military and diplomatic purposes until the development of electronic and optical telecommunications. In the past twenty-five years, cryptography evolved out of its status of "classified" science and offers now solutions to guarantee the secrecy of the ever-expanding civilian telecommunication networks. Although confidentiality is the traditional application of cryptography, it is used nowadays to achieve broader objectives, such as authentication, digital signatures and nonrepudiation

Background

Quantum Cryptography

Based on the laws of quantum physics, a new type of encryption may offer better protection for companies willing to pay a premium.

Traditional cryptography relies on keys so mathematically challenging that they defy quick decryption efforts. Thus, they require that would-be eavesdroppers have considerable computing resources to crack the code. But as computers become more powerful, faster code cracking becomes more feasible.

On the horizon is a possible solution, a mind-boggling brand of cryptography called quantum cryptography. As the name implies, the system is based on quantum physics (Neeley, 1999). The mere act of intercepting and reading a message encrypted this way would disturb its "quantum state" and therefore scramble it into meaningless bits. In addition, a mechanism would warn the intended recipient that "error rates" have increased since the message was sent so that he or she would know that some potential alterations or interference has occurred.

Nabil Amer, manager of IBM's quantum information department, is leading efforts to make this system a reality. Now working with a prototype, Amer envisions the eventual product as a "compact" card, built from off-the-shelf components that can be installed on a server. Quantum cryptography, in this instance, would work by encoding bits of information into single photons - the tiny particles of energy that make up light - polarizing them in one of two directions, and transmitting them through channels such as fiber-optic cable over short distances.

"Quantum physics tells me that I cannot copy or clone anything," says Amer. "It gives me absolute security. If there is an eavesdropper, we will instantly know."

Amer bills the new twist on technology as most practical in securing "islands," such as a set of extremely sensitive servers, within a network. He says that as e-commerce takes off, companies might ...