Cryptography is the science of securing information by transforming it into a form that cannot be easily understood by unauthorized individuals. Traditional cryptography is based on mathematical problems that are difficult to solve, but as quantum computers become more powerful, these problems will become easier to solve. Quantum cryptography is a promising approach to data security that is immune to attack by quantum computers. It uses the principles of quantum mechanics to create secure communication channels. This article provides an overview of quantum cryptography, including the basic principles, different types of quantum cryptographic protocols, and some of the challenges that are still being addressed. The article also discusses the...