How do we exchange a secret key in the clear? Spoiler: We don't - Dr Mike Pound shows us exactly what happens.

Mathematics bit: https://youtu.be/Yjrfm_oRO0w
Computing Limit: https://youtu.be/jv2H9fp9dT8

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This video was filmed and edited by Sean Riley.

Computer Science at the University of Nottingham: https://bit.ly/nottscomputer

Computerphile is a sister project to Brady Haran's Numberphile. More at http://www.bradyharan.com