Lesson: [WIP] EV3 - Telegraph Machine: Key Exchange

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This lesson shows students how to use Diffie-Hellman key exchange (using relatively small prime numbers). This lesson introduces a practical use for the modulo operation and prime numbers, and is a neat demonstration of mathematics applied to cryptography.

After completing this lesson, students should be able to:

  • Describe how the Diffie-Hellman key exchange works in theory.
  • Exchange a message with another group without the teacher being able to decrypt the message.
  • Explain why the Diffie-Hellman key exchange is secure.
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(C) 2015 Ernest Gu, CC-BY