Implement Caesar Cipher

aditigupta17 commented 6 years ago

Description

The Caesar Cipher technique is one of the earliest and simplest method of encryption technique. It’s simply a type of substitution cipher, i.e., each letter of a given text is replaced by a letter some fixed number of positions down the alphabet. For example with a shift of 1, A would be replaced by B, B would become C, and so on.

Thus to cipher a given text we need an integer value, known as shift which indicates the number of position each letter of the text has been moved down. The encryption can be represented using modular arithmetic by first transforming the letters into numbers, according to the scheme, A = 0, B = 1,…, Z = 25.

Input:

A String of lower case letters, called Text.
An Integer between 0-25 denoting the required shift.

You are expected to write a program that receives a Text (string) and Shift value( integer) and returns the encrypted text.

Details

Technical Specifications:

Type of issue: No more than one implementation will be accepted for each language. Once the implementation for a language has been taken up (i.e if it is checked in the 'Issue Progress' section), you must choose from the remaining.
Time Limit: Issues will be given on a first-come, first-serve basis. Once you take this issue up, you must complete it within 2 days, failing which the issue will be allocated to the next person who requested for this issue.
Additional instructions: While making the Pull Request, attach screenshots of 5 sample inputs and their corresponding output.

Issue requirements / progress

[x] C
[x] C++
[x] Python
[x] Java

Resources

https://learncryptography.com/classical-encryption/caesar-cipher

Directory Structure

For this issue, use the following directory of the Hacktoberfest-2k18 repository: /systems/cryptography/caesar-cipher/language_name (where language_name is one of the languages mentioned above.)