Cipher

Cipher is a command-line tool for encrypting and decrypting text using passwords and sets of keys. It also provides an option to hide the length of the text.

Encrypt Function

The encrypt function transforms the input text into an encrypted form using the provided password and key set. Here’s a breakdown of how it works:

1. Padding: If the hideLength argument is set to 1, the function pads the text with * characters until its length is a power of 2. This is done to obscure the original length of the text.

2. Encryption: Each character in the text is replaced based on its position, the password, and the key set. The character's index in the chars list is incremented by the sum of:

   • The password value for the current position.
   • The key value for the current position.
   • The length of the text.

   This transformation is applied to each character in the text.

Hide Length Function

The hideLength option is used during encryption to obscure the length of the text. When hideLength is set to 1:

• The text is padded with * characters until its length becomes a power of 2.
• This padding helps to prevent revealing the length of the original text, adding an extra layer of obfuscation.

When hideLength is set to 0 or not provided, the text is encrypted without any padding, and the length remains visible.

Features

• Encryption: Encrypt text using a password and a set of keys.
• Decryption: Decrypt text using the same password and set of keys.
• Hide Length: Optionally hide the length of the text during encryption.

Prerequisites

• Java Runtime Environment (JRE) 8 or later.

Download

Download the latest release of cipher.jar from the releases section.

Usage

To use Cipher, run the JAR file with the required arguments. Open a terminal or command prompt and use the following syntax:

java -jar cipher.jar <command> <password> <keySet> <text> [hideLength]

Arguments

• <command>: Specify e for encryption or d for decryption.
• <password>: The password used for encryption or decryption.
• <keySet>: The set of keys used for encryption or decryption.
• <text>: The text to encrypt or decrypt.
• [hideLength] (optional): Specify 1 to hide the length of the text during encryption. By default, it is 0 (false).

Examples

• Encrypt Text

java -jar cipher.jar e "password" "1-2-3 22-4" "Hello, World!" 1

This command encrypts "Hello, World!" with the password "password", using the key set "1-2-3 22-4", and hides the length of the text.

• Decrypt Text

java -jar cipher.jar d "password" "1-2-3 22-4" "EncryptedTextHere" 0

This command decrypts "EncryptedTextHere" with the password "password", using the key set "1-2-3 22-4", and does not hide the length of the text.