From the course: Programming Foundations: Discrete Mathematics
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Cryptography
From the course: Programming Foundations: Discrete Mathematics
Cryptography
- Cryptography is the science of encrypting and decrypting information. You use it every day without realizing it. Have you sent an email today? If so, hopefully your message was encrypted by your mail service provider before it was sent along its way. The person on the other end receives your message and it's automatically decrypted for them to view the content. Messages start out as plain text which can then be converted to a numeric version of the message. Only the receiver knows the key to decrypt back to meaningful words. Modern cryptosystems rely on number theory where the encryption and decryption procedures are mathematical functions whose input and out are integers. The Ceasar Cipher is one of the earliest known and simplest ciphers. It is a type of substitution cipher in which each letter in the plain text is shifted a certain number of places down the alphabet. For example, a shift of three letters would move all the letters down three spaces. Then, we send a text with…
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