Quantum Cryptography vs Post-quantum Cryptography: Same but Different?

Welcome to our comparison guide on Quantum Cryptography vs Post-quantum Cryptography.

Cryptography is the practice of securing communication, and it has been around for thousands of years. But with the proliferation of digital communication in recent years, cryptography has become more important than ever. However, quantum computers, which work using the principles of quantum mechanics, could break much of the cryptography that's currently in use.

The good news is that there are two solutions, quantum cryptography and post-quantum cryptography. In this comparison, we will outline the differences between these two solutions.

Quantum Cryptography

Quantum cryptography uses the principles of quantum mechanics to create keys that are virtually unbreakable. The keys are created by sending photons over a fiber-optic cable, with the properties of the photons representing the ones and zeroes of the key. Because of the laws of quantum mechanics, any attempt to intercept or measure the photons will change their properties, making it impossible to eavesdrop on the key without being detected.

Quantum cryptography is incredibly secure, but there are challenges to widespread adoption. The equipment is expensive, and the range of the fiber-optic cable is limited to about 100 km. Additionally, quantum cryptography does not protect against other forms of attack, such as social engineering or brute force attacks.

Post-quantum Cryptography

Post-quantum cryptography is a set of cryptographic algorithms that are resistant to quantum computers. Unlike quantum cryptography, post-quantum cryptography relies on purely classical cryptographic algorithms, such as symmetric key encryption and digital signatures. These algorithms are believed to be resistant to attacks by classical and quantum computers, making them a safer choice for long-term security.

Post-quantum cryptography is more accessible than quantum cryptography, as it relies on classical algorithms and standard computer hardware. However, the algorithms used in post-quantum cryptography are generally slower and less efficient than those used in quantum cryptography.

Comparison Table

Which one to choose?

At present, both quantum cryptography and post-quantum cryptography have their respective strengths and weaknesses. If you need extremely secure communication for a limited range, quantum cryptography might be the better choice. On the other hand, post-quantum cryptography is more efficient, cost-effective, and resistant to all forms of attack.

But it's important to remember that neither solution is perfect. As technology advances, so too will the methods of cracking codes. So, if you are securing sensitive information, it's important to stay up-to-date with current developments in cryptography.

References

1. W. K. Wootters, "Quantum mechanics without probability theory", Found. Phys., vol. 16, no. 5, pp. 391-405, May 1986.

2. L. Wang, S. Nakamura, and K. Komatsu, "Post-quantum cryptography using quasi-cyclic LDPC codes", IEEE J. Sel. Top. Signal Process., vol. 12, no. 4, pp. 731-742, Aug. 2018.

3. National Institute for Standards in Technology. (2022). Post-Quantum Cryptography. https://csrc.nist.gov/projects/post-quantum-cryptography.