Is It Necessary to Study Classical Cryptography Before Quantum Cryptography?

The question of whether it is necessary to study classical cryptography before moving on to quantum cryptography is intriguing and complex. Many experts and researchers see the value in having a solid foundation in classical cryptography before delving into the more advanced field of quantum cryptography. However, others argue that the two disciplines have distinct challenges and do not always require prior classical cryptography knowledge.

The Argument for Studying Classical Cryptography First

Much of the fundamental understanding in quantum cryptography relies on a strong background in the principles of classical cryptography. Concepts such as information theoretical cryptography, including Shannon's definition of a perfect cipher and the one-time pad developed by Vernam, are crucial. Additionally, understanding authentication codes as developed by Wegman and Carter provides a solid grounding for understanding the security implications in cryptographic systems. In this view, it is beneficial to grasp the traditional concepts before tackling the quantum realm.

The Case Against Pre-requisite Classical Cryptography Knowledge

From my experience and observations, I find that the transition from classical to quantum cryptography can be quite formidable. It is not uncommon for individuals who have studied quantum physics or related fields to embark on quantum cryptography research without a deep understanding of classical cryptography. For example, I have a physicist friend who studied computer science and physics before diving into quantum cryptography. Her formal education did not include advanced classical cryptography beyond the general course material.

My interactions with peers from my research group working in quantum and post-quantum cryptography suggest that the problems they solve are fundamentally different from those in classical cryptography. While some of my peers have extensive knowledge in classical cryptography, others have only basic knowledge and do not seem to be at a significant disadvantage. This experience suggests that while classical cryptography knowledge can be beneficial, it is not strictly necessary to excel in quantum cryptography research.

Conclusion

In conclusion, while a solid understanding of classical cryptography can be advantageous when transitioning to quantum cryptography, it is not a strict requirement. The key to success in quantum cryptography lies in understanding the fundamental principles of quantum mechanics and the unique challenges of the quantum domain.

Keywords: quantum cryptography, classical cryptography, information theoretical cryptography