Polyalphabetic Ciphers: practical activity

In this activity you will learn about polyalphabetic ciphers. We will examine the Vigenère cipher in particular, and you will have the opportunity to use it to communicate with other learners.

In the 15th century, the first recorded polyalphabetic cipher was described by Leon Battista Albert. The idea wasn’t widely used at first because of its complexity, but when people began to realise that cryptanalysts would always have the upper hand over monoalphabetic ciphers, that changed.

In this activity, you will create secret messages using polyalphabetic ciphers. You can check your results online and start sending secret messages to other learners.

Your task

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Try creating secret messages to send to your peers by clicking here. Can you decode the messages sent by the others?

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This article is from the free online course:

An Introduction to Cryptography

Coventry University