Senior Physics: A lesson in Cryptography

Senior Physics: A lesson in Cryptography

On Wednesday May 6th, 2015, twenty of Rockway’s Physics Students were treated to a high-tech lecture and a hands-on activity presented by Dr. Martin Laforest from the University of Waterloo’s Institute for Quantum Computing (IQC).

The lecture introduced our students to Cryptography (Coding and Decoding), a topic of utmost importance to security on the Internet and integral to our online banking systems.

Students learned that classical Crypto Systems can be eavesdropped on too easily but a Quantum Crypto System can detect an eavesdropper instantly. Message transmission is then halted, re-encrypted and re-sent making it impossible to successfully intercept. Laforest explained that these Quantum Systems rely on the polarization of light and our ability to send a single photon (a light particle with wave properties) at a time.

Students then had the opportunity to work in teams and use lasers and polarizers to send a polarized laser light signal. Only when the receiving polarizer was properly oriented could the signal be detected and displayed by Laforest’s laptop computer. Any interruption of the signal was immediately detected.

This may sound complicated, but at its core, students were challenged to apply their Physics knowledge to a real-world cutting edge application, guided by a leading researcher in the field. What a fantastic opportunity, and a tribute to how our deepest understandings about our Universe have important applications in our daily lives. Yeah Physics!

Note: This event was the follow-up to the UW Physics Tour our students participated in early spring.

Steve Pfisterer, Physics Teacher