What is the purpose of post-quantum cryptography? | Sectigo® (2024)

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The purpose of post-quantum cryptography and when to prepare

Quantum computing is no longer science fiction material. Recent advancements have raised concerns among security experts. A quantum computer powerful enough to break today's cryptographic algorithms may be just 10-15 years away from becoming a reality.

Organizations must respond to this new threat. The good news is that post-quantum cryptography (PQC) is now available to help organizations future-proof their data security measures against the looming quantum apocalypse.

Let's explore what quantum computing means for cybersecurity, why classical cryptography can't protect us from quantum threats, what PQC is, the different types of PQC, how to implement quantum-resistant solutions, when to start preparing for quantum-safe cryptography, and how to get started.

Understanding quantum computing

Quantum computing leverages the principles of quantum mechanics to perform tasks and solve problems at speeds unachievable by the computers we use today. Classical computers use bits, which are binary (i.e., 0s and 1s), while quantum computers use qubits, which can exist in multiple states simultaneously.

Quantum computers excel at factoring large numbers, searching unsorted databases, and simulating quantum systems. Unlike classical computers that follow a sequential execution model, they can perform numerous calculations in parallel. Their unprecedented speed allows them to easily break today's encryption methods—such as Rivest-Shamir-Adleman (RSA), Elliptic Curve Cryptography (ECC), and Digital Signature Algorithm (DSA), the foundation of secure communications on the internet— posing significant threats to data security and privacy.

The vulnerabilities of classical cryptography

RSA and DSA involve algorithms that require solving complex mathematical equations. The vast number of possibilities makes it almost impossible for even the most powerful classical computers to crack the code in a reasonable amount of time. EEC uses the same concept but is based on the mathematical algorithms of elliptic curves.

RSA and DSA face key length concerns as computational power increases, while poorly chosen curves for ECC may introduce vulnerabilities. Advancements in quantum computing mean we're approaching the point where quantum computers will become powerful enough to solve the mathematical problems behind today's encryption algorithms.

To mitigate this threat, we must develop and adopt PQC algorithms to withstand attacks from quantum computers and ensure long-term data security.

What is post-quantum cryptography?

Post-quantum cryptography is a set of cryptographic techniques and algorithms designed to address classical cryptography's vulnerabilities.

PQC algorithms ensure the long-term security and privacy of digital communications and data exchange in a future where quantum computers can efficiently break classical cryptographic schemes. They will be critical for maintaining the confidentiality, integrity, and authenticity of data. By transitioning to quantum-resistant algorithms, organizations can future-proof their security measures and protect sensitive information from quantum threats.

The role of NIST in quantum cryptography

The National Institute of Standards and Technology (NIST) held a public competition to select and standardize a new set of cryptographic “primitives” that are secure against cracking by quantum computers. These well-vetted and practical post-quantum algorithms use fundamentally different mathematical techniques than the related math problems underlying RSA and ECC. They're equipped to protect sensitive data in a quantum-threatened environment.

There are four winning algorithms: The CRYSTALS-Kyber algorithm provides general encryption for accessing secure websites. CRYSTALS-Dilithium, FALCON, and SPHINCS+ support digital signature or remote document signing. NIST recommends using Dilithium as the primary algorithm and FALCON for smaller signatures.

Types of post-quantum cryptography

There are many approaches to creating quantum-resistant cryptography. Here are the most commonly used ones:

• Code-based cryptographyuses error-correcting codes and relies on the hardness of decoding specific linear codes, such as the McEliece cryptosystem.
• Hash-based cryptography leverages hash functions to create secure digital signatures and authentication protocols, using one-time signature (OTS) schemes like the Lamport-Diffie or the Merkle signature scheme.
• Multivariate polynomial cryptographyinvolves solving systems of multivariate polynomial equations. One such well-known scheme is the unbalanced oil and vinegar (UOV) system.
• Lattice-based cryptography relies on the hardness of specific lattice-related problems in multi-dimensional spaces. Popular lattice-based schemes include NTRUEncrypt and NTRUSign.

How to implement quantum-resistant solutions

Organizations must start preparing for the quantum apocalypse by implementing quantum-resistant algorithms through quantum-safe digital certificates. These certificates use post-quantum cryptographic algorithms to secure data and protect communication between parties in a quantum-threatened environment.

Companies should use hybrid certificates to ensure a smooth transition as quantum-resistant algorithms are being adopted while classical encryption methods are still prevalent. Hybrid certificates merge classical cryptographic methods and post-quantum cryptographic ones to cover all the bases while ensuring compatibility and interoperability to support a phased transition without compromising security.

When and how businesses should prepare for quantum cryptography

If you rely on classical cryptography, and quantum computers become capable of breaking these systems, your sensitive data and secure communication can be compromised, leading to data breaches, loss of customer trust, regulatory fines, and reputational damage.

As such, businesses should take a proactive stance in preparing for the quantum computing threat because implementing quantum-resistant security measures is a long-term process. Starting your initiatives now allows you to stay ahead of potential security risks and be ready when quantum computers become a threat.

While the timeline for quantum computing threats is uncertain, understanding these three phrases can help you plan your transition to quantum-safe encryption methods:

• Near-term (5-10 years): Quantum computers are unlikely to be powerful enough to break classical encryption widely but are advancing rapidly.
• Mid-term (10-20 years): Quantum computers may threaten some encryption methods, necessitating the transition to post-quantum cryptography.
• Long-term (20+ years): Quantum computers may be able to break most classical encryption, making quantum-resistant solutions essential.

Your level of readiness depends on these three parameters:

• Shelf life time: The number of years you must protect the data.
• Migration time: The time it takes to migrate the system protecting the information.
• Threat timeline: Time before threat actors can potentially access cryptographically relevant quantum computers.

Your implementation plan should ensure that the sum of the shelf life and migration times is shorter than the quantum threat timeline.

Overcoming the challenges of implementing post-quantum cryptography solutions

Not preparing for quantum threats poses substantial security risks, and organizations can't afford to ignore the importance of implementing PQC solutions.

When planning the transition, consider the costs of change to support research, software and hardware upgrades, and staff training. Your expenses will depend on the size of your organization and the complexity of your infrastructure, but the investment will be essential for long-term data security.

Continuously adapt your cybersecurity measures as quantum computing advances. For example, monitor the progress of quantum technologies, evaluate the readiness of quantum-resistant algorithms, and stay informed about best practices in securing digital communications. Additionally, encourage proactive measures among employees, partners, and customers for long-term data protection.

To help organizations transition to a post-quantum world, Sectigo has introduced quantum-safe hybrid TLS/SSL certificates. Learn more about our solutions and download the Sectigo Quantum Safe Certificate Toolkit to start your PQC journey.

Want to learn more? Get in touch to book a demo of Sectigo Certificate Manager!

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