Rotational (AKA shift) Encrypton / Decryption

Introduction

A rotational encryption / decryption implementation. A play toy for your enjoyment.

Note: This is a toy. Do not use it in production or any serious environment.

Motivation

This project was enspired by:

• A general interest in cryptography.
• History. See: Caesar Cipher
• Reading. Example:
  • An Introduction to Mathematical Cryptography, by Jeffrey Hoffstein, Jill Pipher, and Joseph H. Silverman.
  • A PDF might be available at: Intro PDF
• Having some fun coding.

Technical Notes

• Written in the go language, and useful only in that environment.
• Uses go modules. You will need a module capable version of go (go1.11+).
• Hosted on github.

Installaton

Use git clone to obtain a copy. Not available using go get.

Your project will need to have an appropriate go.mod to use red.

Character Set

The only supported character set is UTF8. Errors are returned if an alphabet, plaintext or ciphertext parameter contains invalid characters.

Shift / Rotation Values

Shift Value 0

Supported. You get what you ask for in terms of encryption.

Shift Value a Multiple of Alphabet Length

Supported. Treated like a shift value of 0.

Shift Values Greater Than 0

All values are supported. Note that by default this is a left shift of the alphabet.

Shift Values Less Than 0

All values are supported. Note that by default this is a right shift of the alphabet.

Shift Values Left Versus Right

Default is a positive shift value uses a left shift of the alphabet.

And a negative shift value uses a right shift of the alphabet.

Default behavior can be changed by calling the constructor with an appropriate instance of NewParms.

Examples

Examples are found in the subdirectories of the cmd directory.