CAOT 31 Lecture 16:
13 Sep 2020
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Reconstruct message: hleol: not the greatest encryption method, cipher improves when more lines are used. 1: write out the message beneath the key (with padding) If a key can be any arrangement of a regular alphabet (a-z), we can generate a massive number of distinct keys (26! = 4000,000,000,000,000,000,000,000,000) arrangements: with these many keys a brute force attempt at decryption can be very time consuming, however, monoalphabetic ciphers considered a very weak form of encryption. Substitution karma sutra cipher: developed in the 4th century. Involves randomly pairing letters of the alphabet, so each letter in a message is substituted by its partner. Substitution cracking monoalphabetic ciphers: even the caesar cipher seems challenging without a computer, if you are using brute force decryption, there is, however, an alternative to brute force decryption: letter frequency analysis. Substitution polyalphabetic ciphers: similar to monoalphabetic ciphers, characters in the plain text (like a") could encrypt to different characters in the.
