Cryptography By Sunny Mahesh and Andy Yuwen

What is Cryptography • Cryptography = Secret Messages = Cool Stuff• Ciphers• Difference between plaintext and ciphertext• Enciphering and Deciphering

Substitution Ciphers

Hill Ciphers • Hill Ciphers encode messages of plaintext in

successive pairs.• For a Hill n-cipher, pairs of length n are taken and

are enciphered by a n by n matrix•

Hill Cipher Example Part 1•

Hill Cipher Example Part 2•

Hill Cipher Example Part 3•

Modular Arithmetic

• A Cooler Way To Do Math

Reciprocal Mods

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Inverse of a Matrix mod 26

• Why are we still doing this? Because we’re cool, Dealz with it

Example of Inverse of a Matrix mod 26

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Decoding

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Decoding #hardcore#jamesbondstyle

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Decoding #hardcore#jamesbondstyle

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Decoding #hardcore#jamesbondstyle#2

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Decoding #theeasypart#3

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Mission Accomplished, JK

• OK. Now Its Your Time Secret Agents. Complete the final mission and receive your award.

• We have intercepted the code