GES CLI

The software utilizes a simple block cipher encryption algorithm to encrypt and decrypt data. It uses a home-grown encryption algorithm called GES based off of the feistel cipher structure.

Developed and maintained by Mohammed Adekunle

GES Algorithm

Based off of the feistel cipher structure, the block size of the algorithm is 128 bits with a 128 bit key. It utilizes a parity drop for every 8th-bit to reduce the key size to 112 bits, followed by a shift function which condenses the key to 96 bits. Then DES S-Box substitution is done to generate unique 64-bit round keys.

Installation

You can compile the binary manually using the go build command or you can compile via the build system using the make tool.

Via Go Build

To compile via go build, you will require the go 1.22 binary installed. Then follow the steps below:

• Run cd cmd/ges to change your terminal path
• Run go build . to generate a build of the ges cli for your operating system architecture
• Run ./ges to get started

Via make

To compile via make, you will require a recent version of the make utility installed. Then follow the steps below:

• Run make build to trigger an automated build of the project
• Run cd build/binto change your terminal path to the build directory
• Run ./ges to get started

Usage

Before you can get started with encryption or decryption you need to generate an cipher key. Cipher keys for the GES algorithm need to be 128-bits large. An utiliy is provided for this in the ges binary called keygen.

To encrypt data, an encrypt utility is provided in the ges binary which can either encrypt a provided input file or encrypt data directly from the standard input.

Decryption is similar with with the decrypt utility in the ges binary which can also decrypt a provided input file or decrypt directly from the standard input.

Special Notes:

• Like any other cipher, attempting to decrypt a cipher text with the wrong cipher key will not give the expected plain text. But neverthelesss, a plain text will be generated.
• The GES algorithm should not be used in a production environment as it does not meet any international standards for encryption (It is a proof of concept).

License

This project is licensed under the MIT license.