Understanding Post-Quantum Cryptography: Securing Tomorrow's Data Today

Public key cryptography is an integral part of our daily internet activities. Whether you're browsing your favorite website, watching the latest trending series, sending an email, online shopping or social media messaging, it's there, silently ensuring that your data remains secure. But with the advent of quantum computing, the security provided by traditional public key cryptography is under threat. This blog post aims to shed light on the need for new algorithms and the emergence of post-quantum cryptography.

Objectives

• Gain an understanding of the need for new algorithms
• Understand post-quantum cryptography

Traditional Public Key Cryptography: A Quick Primer

Before we dive into post-quantum cryptography, let's take a moment to understand the mechanism behind traditional public-key cryptography. What really makes these algorithms secure?

Traditional public key cryptography relies on two types of mathematical problems: prime integer factorization and the discrete logarithm. These problems are relatively straightforward to compute in one direction but extremely difficult to reverse without specific information.

Prime Integer Factorization

For example, given two huge prime numbers, it's easy to compute their product. However, given the product, it is exceedingly difficult to determine the original prime numbers.

For instance, while it’s simple to multiply 661 and 251 to get 165,911, figuring out the prime factors of 165,911 is significantly harder without knowing them in advance. Real-world applications use much larger prime numbers, adding to the complexity.

Discrete Logarithm

The discrete logarithm problem is another one-way function that is easy to compute but hard to reverse. In the context of cryptography, this often involves a large prime number p and a generator g. Given g and x, where y ≡ g^x  mod p, it is easy to compute y. However, given y, it is extremely difficult to determine x.

For example, if g = 5, p = 23 and y = 8, finding x such that 8 ≡ 5^x mod 23 is a hard problem. In real-world applications, g, p and y are much larger, making the problem even more challenging. In this example, x=6 satisfies 8 ≡ 5⁶mod 23.

In simple terms, public key cryptography relies on these mathematical problems to exchange keys for encryption and to create digital signatures.

The Quantum Threat

If these algorithms have been working fine, what's the issue? The problem lies in the advancements in quantum computing. With tech giants like IBM, Google and Microsoft investing hundreds of millions of dollars, significant breakthroughs in quantum computing are happening.

In 1994, the mathematician Peter Shor devised an algorithm that can quickly and efficiently solve the prime factorization and discrete logarithm problems. Fortunately, Shor’s algorithm only runs on quantum computers which are still in their infancy. However, it is only a matter of time before powerful enough quantum computers can be built to break the cryptographic algorithms we currently rely on.

Some might think, "There’s time left. Why worry now?". Unfortunately, that’s a misconception. Communications exchanged today can be intercepted and stored, only to be decrypted later when quantum computers become available. There is evidence suggesting that some entities might already be engaging in such activities as revealed by Edward Snowden. This means that today’s communications are at risk and need to be secured now to protect future data integrity.

NIST Post-Quantum Cryptography (PQC) Standardization

Recognizing the impending threat, the National Institute of Standards and Technology (NIST) launched a competition to develop new cryptographic algorithms that are resistant to quantum attacks. Researchers from around the world proposed new algorithms based on different mathematical problems such as lattice-based cryptography, code-based cryptography and others. Over several years and rounds, these algorithms were scrutinized and tested.

Some of these algorithms, such as CRYSTALS-Kyber and CRYSTALS-Dilithium, have emerged as leading candidates for standardization. While they haven't been fully standardized yet, they are being actively evaluated and adopted by various organizations. For example, the German Federal Office for Information Security (BSI) and the French ANSSI endorse FrodoKEM for post-quantum security.

Contributions from cyberstorm.mu

Cyberstorm.mu, has been actively working and contributing towards post-quantum algorithms. We have analyzed the impact of post-quantum cryptography in protocols such as QUIC and DNS, and contributed to open-source projects by OpenQuantumSafe. This hands-on experience has given us unique insights into the practical challenges and solutions for integrating post-quantum cryptography into existing systems.

Global Adoption

The adoption of post-quantum cryptography is gaining momentum globally. Singapore and the White House are among the entities that have embraced these new algorithms, signaling a shift towards quantum-resistant security measures.

Transitioning to Post-Quantum Cryptography

It’s important to note that post-quantum cryptographic algorithms have not yet withstood the test of time. As such, the transition is happening in a hybrid manner where traditional cryptographic methods are used alongside post-quantum algorithms to ensure a smooth and secure shift.

Conclusion

The era of quantum computing is on the horizon, bringing with it both incredible opportunities and significant challenges. While traditional public key cryptography has served us well, the advent of quantum computers necessitates the development and adoption of new cryptographic algorithms. By understanding and preparing for these changes now, we can ensure that our data remains secure in the future.

As we continue to explore the realm of post-quantum cryptography, it's crucial to stay informed and proactive. After all, securing tomorrow's data today is not just a necessity; it's a responsibility.