🔐 RSA Cryptography in Java

This Java program demonstrates a simple implementation of RSA encryption and decryption. The user is prompted to choose upper limits for prime numbers p and q, which are used to generate public and private keys. It then allows encrypting and decrypting a message securely using RSA principles.

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📌 Features

• Prime number generation for RSA key components
• Calculation of public (e) and private (d) keys
• Encryption using C = P^e mod n
• Decryption using P = C^d mod n
• Uses BigInteger for large number support
• Custom base-126 encoding to convert numeric ciphertext to printable characters

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🛠️ How to Run

Requirements:

• Java 8 or higher
• A terminal/command prompt

Steps:

1. Clone the Repository:

   git clone https://github.com/your-username/rsa-cryptography-java.git
   cd rsa-cryptography-java