1. In cryptography, a Caesar cipher, also known as shift cipher, is one of the simplest and most widely known encryption techniques.
2. The Caesar cipher is named after Julius Caesar, who used it, more than 2000 years ago, to protect messages of military significance
3. It is a type of ___________ cipher in which each letter in the plaintext is replaced by a letter some fixed number of positions down the alphabet.
4. For example, with a left shift of four, E would be replaced by A, F would become _______, and so on.
5. The cipher illustrated below uses a left shift of _____, so that each occurrence of E in the plaintext becomes B in the ciphertext.
6. When encrypting, a person looks up each letter of the message in the "plain" line and writes down the ____________________.
7. What would the result of deciphering the following ciphertext be, assuming a right shift of 3.
8. The encryption can also be represented using ________________ by first transforming the letters into numbers.
9. To cipher a given text we need an integer value, known as a ____ which indicates the number of position each letter of the text has been moved down
10. The following code shows the start of an attempt to code a caeser cipher. If 'A' (capital A) is entered, what would the output be?
11. Below, an attempt has been made to extend the program to print out a letter. Assuming 'c' is entered into the program, and we wish 'b' to be output, what needs to be entered instead of 'x' on line 7?
12. What is line 6 of this code doing?
13. One python code snippet uses modular arithmetic in the following way. Why is it necessary to % by 26 to arrive at the correct answer?
14. What line needs to be changed (and to what) in order for the input "BCD" to result in "ABC". (currently it results in "CDE")
15. On line 21 of the following code, what would the output be, if the Shift was changed to '5' instead of '1'?