Menu

Transitioning to Post-Quantum Cryptography (PQC) Adoption

Quantum computing effectively breaks the encryption that safeguards our digital universe today, including RSA and ECC. And while the exact timeline for cryptographically relevant quantum computers (CRQCs) is still fuzzy, we are already firmly in the post-quantum (PQ) era.

“Harvest now, decrypt later” (HNDL) style attacks that target long-life data and devices are underway, post-quantum cryptography (PQC) algorithms are available from NIST, and there are an increasing number of government PQC mandates and timelines across sectors. With that, it is well past the time to move from PQ preparedness to PQC adoption.

PQC around the globe

Transitioning our digital universe requires global collaboration across governments and industry. Some of the more notable initiatives include the NIST Post-Quantum Cryptography Project, the National Cybersecurity Center of Excellence Migration to Post-Quantum Cryptography, the Internet Engineering Task Force (IETF), the Open Quantum Safe (OQS) project, and MITRE’s Post-Quantum Cryptography Coalition.

NIST PQC standards

After running a global competition, NIST published the first three PQC algorithms in August 2024:

  • ML-KEM (FIPS 203) – module-lattice-based key-encapsulation mechanism standard (formerly CRYSTALS-Kyber)
  • ML-DSA (FIPS 204) – module-lattice-based digital signature standard (formerly CRYSTALS-Dilithium)
  • SLH-DSA (FIPS 205) – stateless hash-based digital signature standard (formerly SPHINCS+)

NIST also selected HQC in March 2025 as a backup for general encryption, with a draft standard expected in 2026.

Hybrid vs. Pure PQC migration

One of the ongoing debates is whether to take a hybrid or pure approach to PQC migration. Hybrid PQC migration applies both a traditional public key algorithm like RSA and a PQC algorithm together in the same handshake or signature scheme.

Pure PQC migration replaces all traditional algorithms with PQC algorithms for all cryptographic assets. While pure PQC migration helps ensure quantum readiness now and provides a simpler long-term architecture, it is often incompatible with legacy systems that cannot handle PQC key sizes and message formats and presents with a higher migration risk. In comparison, a hybrid approach affords a more gradual PQC migration with operational continuity but comes with added overhead and complexity.

ANSSI in France and BSI in Germany both favor a hybrid approach to PQC migration, expressing concerns over the relatively untested nature of new standards to real-world attacks. And the European Commission has published the Post-Quantum Cryptography Implementation Roadmap for EU Member States that promotes a hybrid approach employing PQC alongside existing cryptographic approaches or with quantum key distribution (QKD).

However, the U.S. National Security Agency (NSA) favors a pure approach with exclusive PQC algorithm use by 2030 for all National Security Systems (NSS). As well, the UK’s National Cyber Security Centre (NCSC) advises that a hybrid approach should only be used as an interim measure on the path to full PQC adoption.

PQC migration is a staged enterprise-wide transformation

Hybrid or pure, the journey to PQC is not a simple flip of the switch, but rather a staged enterprise-wide transformation. Armed with NIST’s PQC algorithms, here is a practical roadmap to facilitate your own PQC journey.

Source: Entrust.com