Encryption is the key to information security. The key to modern encryption is that using only public information, a sender can lock up their message in such a way that it can only be unlocked by the intended recipient. The resource begins with a detailed explanation of the activity and how the process of...

Cryptographic techniques enable information to be shared with other people, yet still maintain a surprisingly high level of privacy. This activity illustrates a situation where information is shared, and yet none of it is revealed: a group of students will calculate their average age without anyone having to reveal...

This activity shows how to accomplish a simple, but nevertheless seemingly impossible task -making a fair random choice by flipping a coin, between two people who don’t necessarily trust each other, and are connected only by a telephone. The resource begins with a detailed explanation of the activity and...