Goldwater Scholar Reveals Talent for Cryptography

John Parish likes to stay as busy as a yellow jacket. When he's not in class or researching quantum cryptography, he's building a robotic sub or working for the Department of Defense as part of Georgia Tech's cooperative education program. As Tech's newest recipient of the national Barry Goldwater Scholarship, all his hard work seems to be paying off.

"John is the caliber of undergraduate student who comes along only once or twice in an advisor's career," said Steven McLaughlin, professor of electrical and computer engineering and director of Georgia Tech Lorraine in Metz, France. "He is certainly the best undergraduate student I have worked with in my twelve years of teaching and research."

Parish came to Tech from Houston in the fall of 2002. When he was in middle school and high school, several people told him he'd never make it in college, especially in any field that was math or science related.

Now, he's working with McLaughlin on developing a method for encrypting communications that will be able to withstand the growing power of computers to crack them.

"A lot of the cryptographic methods in use now are still based on computational complexity," Parish said. "The idea is that computers are going to keep getting faster and people are going to be able to break those easily. If someone develops a quantum computer, you'd be able to break virtually any cryptographic protocol that's based on computational complexity."

One of the benefits of quantum cryptography over traditional methods is due to a rule in known as the uncertainty principle. That rule states that observing or measuring a quantum particle, such as a photon, disturbs that particle - meaning an eavesdropper would be easily detected because the very act of listening causes changes in the encoded bits.

But serious challenges remain before quantum cryptography can be used reliably. Since quantum cryptography relies on the distribution of one quantum bit between parties, it's currently very difficult to establish wireless communication between two parties if the receiver's location is unknown. It is also difficult to communicate with more than one party at a time.

Parish's research could help solve those problems. In a paper he's submitting for publication in a scientific journal, Parish proposes a solution.

Suppose Agent Base wants to send a secret message to Agent Field, who's in an undisclosed secret location. Base sends out a reference signal - comprised of many photons - in all directions. Field receives the signal and uses a device to reduce it to just one photon, which he encodes with a secret quantum key the two will use to decode their messages. He sends that photon back to Base, who measures it in order to find out the secret key. Base and Field can now communicate using the key to code and de-code their messages.

This method eliminates the need for Field to wear a tracking device, which could also be used by opposing agents. It also allows other agents that Base wants to talk with to receive the reference signal and beam back their own keys to Base.

"Using this you'll be able to have a multi-user free space system. The concept is totally new," said Parish.

Last fall, Parish began a new student organization, the Marine Robotics Group. The group is building a robotic submarine, which they plan to enter into a competition this summer.

As to his future plans, Parish said he would like to earn a doctorate and pursue a research career, most likely in electrical engineering.

Named in honor of the former Arizona senator, the Barry M. Goldwater Scholarship Program is designed to foster and encourage outstanding students to pursue careers in the fields of mathematics, the natural sciences and engineering. The award covers the cost of tuition, fees, books and room and board up to a maximum of $7,500 per year for up to two years.

The Georgia Institute of Technology is one of the world's premier research universities. Ranked seventh among U.S. News & World Report's top public universities and the eighth best engineering and information technology university in the world by Shanghai Jiao Tong University's Academic Ranking of World Universities, Georgia Tech’s more than 20,000 students are enrolled in its Colleges of Architecture, Computing, Engineering, Liberal Arts, Management and Sciences. Tech is among the nation's top producers of women and minority engineers. The Institute offers research opportunities to both undergraduate and graduate students and is home to more than 100 interdisciplinary units plus the Georgia Tech Research Institute.

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