Overview of Post Quantum Cryptography Algorithms

Did you know that as quantum computing advances, experts estimate that around 40% of cryptographic systems will need to be replaced? It doesn’t sound surprising, though. Most of today’s systems rely on traditional cryptography methods to protect data against cyber threats - and it works against classical computers.

But quantum computers are a different breed of machines that require entirely new approaches ... which brings us to the importance of post-quantum cryptography. While the concept is technically interesting, the transition towards PQC adoption comes with a number of challenges.

Today, let's talk about these challenges around post quantum cryptography algorithms and how you can strategize to overcome the barriers to migration:

Understanding Post-Quantum Cryptography

To put it simply, post-quantum cryptography (PQC) is a class of algorithms designed to keep data secure against attacks by both classical and quantum computers. PQC uses mathematical problems to secure communications, making it resilient against quantum attacks. Therefore, post-quantum cryptography becomes essential while also remaining compatible with existing cryptographic environments.

The primary concern stems from traditional elliptic-curve cryptography, which uses elliptic-curve mathematics to generate keys and protect data. While classical computers cannot break to solve and factor large numbers, quantum computers are perfectly equipped to break encryption within a matter of minutes. This is because quantum computing relies on Shor’s algorithm to factor large integers. 

As a result, it allows quantum computers to solve hard mathematical problems, meaning that once large-scale quantum computers are available, data encrypted with RSA and ECC will instantly become vulnerable.

Why Organizations Need to Start Preparing Now

While Google has already announced the Q-day deadline, many organizations are not taking it seriously. The biggest misconception is the assumption that migration can wait until quantum computing is made publicly available. Post quantum security experts highlight that this is a major mistake given the ‘harvest now, decrypt later’ threat model.

The ‘harvest now, decrypt later’ model suggests that if a hacker can intercept encrypted traffic today, they can decrypt it later using future quantum computers to read sensitive information. The problem is that a lot of sensitive information, such as financial records. Government communications and military intelligence will still be highly relevant and valuable for decades. This means that any individual with access to this data will be able to spy, manipulate, or even blackmail.

For organizations, this means they have to protect long-term confidential information by adopting post-quantum cryptography and crypto-agility. Otherwise, delaying migration can cause data breaches and significant financial losses, damaging the organization's reputation. Not only that, but regulatory pressure will also cause organizations to rush to comply for its own sake, which can result in operational inefficiencies.

Five Main Types of Post Quantum Cryptography Algorithms

It is important to understand that post quantum is not a single method or algorithm. Instead, it is a conglomerate of five different cryptographic approaches designed to resist quantum attacks on both classical and quantum computers. This classification is similar to grouping based on hardness assumptions of the mathematical problems for which security is defined. Let's explore these approaches one by one:

1. Lattice-Based Cryptography:

First and foremost, lattice-based cryptography is the most studied and most promising category of post quantum cryptography algorithms. It uses mathematical lattices with high-dimensional structures to build cryptographic security. These lattices are complex geometric structures that serve as the foundation for modern encryption schemes, making even quantum computers struggle to solve them.

ARMchain also uses MLDSA, a lattice-based digital signature scheme, for the security layer of its algorithm. This integration allows our systems to operate securely with quantum-resistant cryptography. As a result, users can transact with a high level of post quantum security.

2. Hash-Based Cryptography:

Hash-based cryptography is a new cryptography that relies on cryptographic hash functions to generate digital signatures rather than on algebraic structures. The security of this approach is strong because it relies on the difficulty of reversing hash functions or finding collisions.

This approach is considered highly secure, but hash-based systems can have their own limitations, such as larger signature sizes or restricted use cases, which have limited wider adoption in this category.

3. Code-Based Cryptography:

Code-based cryptography is a scheme that is built on the difficulty of decoding random error-correcting codes. An interesting fact about these is that they have been studied for decades, since the 1970s, and are widely believed to remain resistant even in the quantum era.

However, due to the large key sizes of these systems, code-based cryptography has never really achieved mainstream adoption. But nonetheless, it remains an important candidate for post quantum security.

4. Multivariate Polynomial Cryptography:

MPC cryptography is highly interesting because it uses multivariate polynomial equations to solve hard mathematical problems for secure encryption and signatures. These systems are computationally very hard and resistant to classical attacks. However, many multivariate schemes have been broken by cryptanalysts over time, leaving this category more experimental than lattice or hash-based systems.

5. Isogeny-Based Cryptography:

Isogeny-based cryptography is a relatively new cryptography. It is an emerging field and is in its experimental phase. This approach relies on mathematical relationships between isogenies of elliptic curves.

It is considered promising due to its small key sizes, but over the years, some proposed systems have been broken. Research in this area is ongoing, but it could be an interesting direction for post-quantum cryptography.

Top 4 Key Migration Challenges in PQC Transition

When it comes to migration from traditional cryptography to post quantum cryptography, one may face a number of significant challenges. Let's discuss them one by one:

1. Cryptographic Discovery and Inventory Gaps

One of the key challenges when adopting post quantum cryptography algorithms can be the complexity of simply identifying gaps across your ecosystem. See, in most companies, encryption is embedded in existing applications, APIs, and databases, and information is often kept without proper centralized documentation. This lack of visibility can cause delays and inefficiencies in the migration process.

The lack of standardization in environments, especially around new cryptography, can make discovery a very time-consuming step for many organizations. But you need to understand that inventory is the most important aspect of migration; without it, planning will be incomplete, leading to security gaps.

2. Performance and Infrastructure Overhead

The problem with post quantum cryptography algorithms is that they usually introduce higher resource and computational demands as compared to traditional encryption methods. For instance, lattice-based schemes entail larger digital signature sizes, higher memory usage, and greater bandwidth consumption.

All these overheads can directly affect latency-sensitive systems and high-throughput cloud services. Therefore, for organizations to adopt PQC, they also need to benchmark PQC algorithms with extensive performance testing and optimization.

3. Legacy System and Protocol Compatibility

For many large-scale organizations, a huge hurdle is the legacy systems. Many legacy systems are not designed to support PQC cryptographic primitives. As a result, integrating PQC may become a bottleneck, as it will likely be blocked by outdated libraries and unsupported frameworks.

To modernize without disruption, organizations need to use phased upgrades and interoperability layers to integrate hybrid cryptographic deployments rather than full replacements. Doing so will allow systems to evolve without the risk of downtime or failures.

4. Vendor Ecosystem Readiness

Stakeholder readiness is a major factor when taking this decision as well. Enterprises that rely heavily on third-party vendors will require coordination, which slows migration. Enterprises using cloud services, communication platforms, or SaaS providers need to ensure that security standards are consistent across vendors and timelines.

For any migration strategy to truly succeed, dependency on external vendors results in delays so organizations will need to collaborate in the ecosystem. This will allow vendors to align with organizations' cryptographic roadmaps.

Top 7 Recommended Steps Before Migration

Before stepping into post-quantum cryptography migration, we recommend that organizations assess readiness and build alignment with stakeholders so they can transition without any disruption:

1. Identify Cryptographic Assets: Before migration, create a comprehensive inventory of all cryptographic dependencies with your applications, databases, APIs, systems, and services.
2. Assess Risk Exposure: Classify your data assets and determine which datasets require long-term protection against quantum attacks, and which systems are the most vulnerable to cryptographic compromise.
3. Evaluate Current Security Infrastructure: Review your existing networking, hardware security modules, and software systems for limitations before preparing for PQC-compatibility.
4. Crypto Agility Strategy: Next, implement a flexible, modular design to simplify future transitions within the cryptographic ecosystem.
5. Conduct Pilot Deployments: Before final deployments to production environments, it is critical to test PQC algorithms in controlled settings to assess the performance impact of deployment.
6. Engage Technology Vendors: We also recommend that you deploy automation tools and cryptographic libraries to upgrade systems and ensure readiness for quantum-resistant technologies across your infrastructure.
7. Establish Long-Term Migration Plans: This is especially important for organizations using legacy systems. Plan phased deployment strategies that align with your business objectives and compliance requirements.

Final Words

Post quantum cryptography represents a paradigm shift in the Web3 world. It is not only inevitable but also essential for the future of cybersecurity. As organizations prepare to tackle this transition, we also need to consider the challenges in transitioning systems from classical cryptography to PQC algorithms. 

It may be difficult for organizations to migrate immediately. But it is crucial to begin planning today so that enterprises are better positioned to defend against quantum threats and navigate the future of cryptography with confidence.