What are quantum-safe and hybrid certificates?
Quantum computing poses an existential threat to RSA and ECC encryption, making post-quantum cryptography (PQC) essential. This article explains quantum-safe certificates, the new NIST PQC standards, and hybrid certificates that blend classical and quantum-safe algorithms to enable a smoother transition. Learn how businesses can prepare now with automation, testing, and crypto agility.
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Quantum computing represents one of the biggest game-changers in the modern digital ecosystem. This will transform computing as we know it, bypassing the long-held restrictions of classical computing and ushering in a new age of innovation.
With these advances come exciting new opportunities in far-reaching areas like artificial intelligence and the internet of things (IoT), but there's a definite downside: The advantages of quantum computing will be accompanied by major security challenges, including a huge shakeup to the status quo of encryption and authentication. Algorithms such as RSA and ECC, which currently protect most digital communications, will easily be broken by future quantum systems.
Post-quantum cryptography (PQC) provides a proactive approach to addressing these emerging threats — yet many enterprises still view it as a future concern rather than an immediate priority. However, this perception is rapidly changing. Now is the time for organizations to begin developing a strategy and blueprint for PQC adoption, including evaluating standards, testing in controlled environments, and planning for future migration paths.
Why quantum computing breaks traditional cryptography
Traditional cryptography relies on a few tried-and-tested algorithms that, until recently, have effectively safeguarded sensitive data by leveraging computational complexity. Options such as RSA (Rivest–Shamir–Adleman) and ECC (Elliptic Curve Cryptography) have served users and organizations well throughout the last several decades, with the assumption that the computing power required for the factorization of large prime numbers would simply be too significant for threat actors to overcome.
Quantum computers change this equation by solving problems that classical systems cannot efficiently handle. One of the best-known quantum algorithms, Shor’s Algorithm, factors large numbers exponentially faster than classical methods, enabling the rapid breaking of RSA and ECC encryption. This shift places the future of digital security at risk unless stronger, quantum-resistant algorithms are adopted.
The urgency behind post-quantum cryptography
The quantum computing timeline shows that the post-quantum era is not as far away as it might seem. Already, the National Institute of Standards and Technology (NIST) has established a strict deadline for deprecating some legacy encryption algorithms and shifting to PQC: This must be accomplished by 2030. This timeline includes the phase-out of RSA-2048 and ECC-256, with a full ban on their use expected by 2035.
This sense of urgency is exacerbated by concerns surrounding harvest now, decrypt later (HNDL) attacks, with bad actors potentially gathering encrypted information already with the intention of decrypting this data once quantum systems become more readily available. As a result, vulnerable data could be exposed retroactively, even if its compromised status is not yet recognized.
Threat actors are actively preparing for the quantum shift, and organizations that delay planning risk falling behind. To stay ahead, enterprises should begin testing post-quantum cryptography solutions now, even before final standards are fully adopted.
What is a quantum-safe certificate?
Digital certificates qualify as quantum-safe if they support post-quantum algorithms that have been purposefully designed to combat attacks from quantum computers.
What are the finalized PQC algorithms?
Some PQC algorithms hold the potential to safeguard digital communication, even as we transition into the quantum era. NIST finalized the following post-quantum encryption standards:
FIPS-203: This standard is based on Module Lattice-Based Key Encapsulation Mechanism (ML-KEM), which enables the generation of secure keys for data encryption. It’s built on the Module Learning with Errors problem which keeps it secure against quantum-enabled attacks. FIPS 203 includes three parameter sets, ML-KEM-512, ML-KEM-768, and ML-KEM-1024, with each higher parameter number providing stronger security at the cost of slower performance and longer keys.
FIPS-204: This standard uses Module Lattice–Based Digital Signature Algorithm (ML-DSA), a suite of algorithms for creating and validating digital signatures. FIPS-204 uses lattice-based cryptography to keep digital signatures secure against quantum computing.
FIPS-205: This standard, also used to secure digital signatures, relies on the Stateless Hash-Based Digital Signature Algorithm (SLH-DSA). The hash-based approach offers an alternative mathematical method to the lattice-based methods in FIPS-204 for resisting quantum computing threats.
What are hybrid certificates?
Hybrid certificates are a proposed solution designed to ease the transition to post-quantum cryptography. They are not yet an established or deployable technology, but rather a potential approach under discussion in the cryptographic community.
The concept behind hybrid certificates is to accommodate current encryption and authentication needs while also helping to prepare organizations for the reality of the quantum age. This unique type of certificate would incorporate both classical and post-quantum algorithms within a single certificate. Each hybrid certificate would include two public keys and two signatures, one using a traditional algorithm such as RSA or ECC, and the other using a quantum-safe algorithm to provide compatibility and resilience.
This potential solution aims to allow a gradual migration towards PQC while maintaining compatibility with existing systems.
How would hybrid certificates work?
The value of the hybrid certificate largely derives from the X.509 standard, which clarifies public key certificate formats and involves the interface description language Abstract Syntax Notation One (ASN.1). The X.509 standard has long been a critical component of SSL/TLS certificates — but hybrid certificates would extend this traditional format to also incorporate future-proof PQC keys and signatures.
With hybrid certificates, non-critical extensions would be able to store PQC-focused details, such as quantum-safe public keys and quantum-resistant digital signatures. Because these elements are not immediately needed to drive compatibility with legacy systems, it would remain possible to continue working with classical algorithms such as RSA or ECC, with legacy systems essentially ignoring PQC elements for the time being. At the same time, PQC-ready systems could detect and validate the post-quantum components, enabling a smooth transition path as support for new standards evolves.
Essentially, this dual approach forms the basis for backwards compatibility by leveraging the current advantages of classical cryptography while also providing a layer of protection that will prove valuable in the future.
Benefits of using hybrid certificates
If adopted, hybrid certificates could offer many advantages that make them a compelling potential option for addressing current and future security challenges. Benefits include:
Interoperability: By offering support for both legacy and PQC-centric systems, hybrid certificates could achieve an elevated level of interoperability that remains out of reach for other types of certificates. This means both current and next-generation clients could validate the same certificate during the migration period.
Crypto-agility: To maintain full security in a rapidly changing digital environment, organizations need to be capable of quickly switching algorithms without also disrupting operations. Hybrid certificates are intended to make this possible, thereby promoting the much-advocated quality known as crypto agility.
Simplicity: Avoid the complications of maintaining separate certificate chains; hybrid certificates would be designed to simplify otherwise complex processes by blending classical and PQC components to form one straightforward and effective certificate. This would limit overhead while reducing the administrative burden that would likely come into play while handling multiple certificate systems or solutions.
Security: PQC promises robust security far into the future, addressing challenges with stronger algorithms. Hybrid certificates are intended to add flexibility by including both classical and post-quantum algorithms, making it easier for organizations to transition if one is later found vulnerable.
Limitations and challenges
Hybrid certificates offer one of the most valuable potential solutions for dealing with both current and future cybersecurity challenges — but they won’t be entirely free of complications. Larger key sizes in quantum-safe algorithms can increase bandwidth and processing requirements, making performance a key consideration in their adoption.
Another potential limitation involves compatibility. Because hybrid certificates are still only a proposed solution, no vendors or systems support them today. If adopted in the future, support may vary across applications and platforms, requiring organizations to carefully evaluate interoperability before deployment.
Another concern worth addressing? The deficits of manual certificate management, which is far less efficient and can place a significant burden on IT departments. This burden will only increase as certificate needs grow more complex, which would be a likely response to the potential adoption of hybrid certificates. Thankfully, automated certificate lifecycle management solutions can resolve these issues, improving both efficiency and security, even as organizations adopt quantum-safe or hybrid certificates.
Why you can't wait for perfect compatibility
The journey towards PQC may currently feel expedited, but this is more of a marathon than a sprint. It will take time for the global PKI ecosystem to successfully adopt PQC, and at some point, a bridge between current and future systems will be needed to streamline this transition. Full support across platforms and vendors will take years, and delaying adoption increases long-term risk.
This is where hybrid certificates could come into play. They may not represent a permanent solution, but could be beneficial during the transition to PQC.
How organizations can start preparing
It's never too soon to begin navigating the shift towards PQC. This begins with a detailed inventory, highlighting all existing cryptographic systems, algorithms, keys, and other assets to determine where key sources of risk currently exist. This inventory forms the foundation for understanding cryptographic exposure and planning effective mitigation strategies.
Several practical strategies can leverage this robust understanding to ensure that systems are prepared for the upcoming quantum transition.
Automate certificate lifecycle management (CLM): As quantum technology advances, there is no room for manual certificate processes. Crypto agility is more readily achieved when leveraging automated CLM, which allows for the seamless issuance and renewal of digital certificates at scale, thereby making it possible to respond swiftly to emerging threats.
Test via sandbox environments: PQC and hybrid certificates will require extensive testing, but sandbox environments provide the perfect opportunity to explore these options within highly controlled spaces. This effort could provide valuable insights into performance or potential vulnerabilities without risking disruptions.
Prioritize long-lived assets: Given the risk of HNDL, it is important to examine assets with extensive lifespans to determine whether they are vulnerable and how difficult it might be to update them in the context of PQC. These priorities may vary but often involve signed contracts, firmware, or even legal records.
Educate teams: IT professionals need to be in the know about quantum threats and PQC. Proactive training initiatives will ensure that these professionals are fully prepared to adopt post-quantum solutions and also leverage complementary strategies such as automated CLM. Training should also introduce PQC standards, available tools, and key considerations for future migration paths.
Sectigo leads the way in quantum readiness
As a PQC trailblazer, Sectigo offers several solutions designed to prepare organizations for the realities of the post-quantum era, starting with Sectigo Certificate Manager (SCM). SCM is a purpose-built platform that automates certificate lifecycle management, enabling faster and more efficient issuance and renewal.
Automated CLM provides a strong foundation for crypto agility, but this effort can be further supported with Sectigo's Q.U.A.N.T. framework, which offers much-needed guidance to simplify the transition to PQC. This end-to-end strategy empowers organizations to take a proactive approach to the upcoming quantum transition but also provides support every step of the way.
Future-proof your security with Sectigo’s quantum-safe solutions
Quantum threats are fast approaching. Exploring hybrid certificates as a future option could provide a well-rounded path for preparation during the transition to PQC, without disrupting current systems. Sectigo offers the support needed to navigate this transition with confidence.
Begin by testing quantum-safe certificates in the ultimate safe space: Sectigo's PQC Labs, which provides a purpose-driven environment for exploring post-quantum solutions. Get started with Sectigo Certificate Manager today or learn more about our quantum-safe opportunities.