Post-quantum trust architectures: Future-proofing privacy, provenance, and verifiability

Privacy programs increasingly depend on systems that can verify key aspects of data handling: confirming user consent, controlling access to data, tracking data lineage, and maintaining audit trails. In fact, the EU General Data Protection Regulation requires organizations to demonstrate valid consent, provide data access, maintain processing records, and secure personal data.

These verification capabilities rely on cryptographic tools, like encryption and digital signatures, to prevent tampering and enable reliable audits. However, the common public key algorithms used today — Rivest-Shamir-Adleman, a system based on the difficulty of factoring large numbers and Elliptic Curve Cryptography, which uses mathematical curves to secure data — are mathematically vulnerable to future quantum attacks like those enabled by Shor’s algorithm. In 2020, the European Data Protection Supervisor warned that this quantum threat “could break currently used cryptography and undermine the protection of personal data.” And in April 2024, the European Commission cautioned that quantum computing could be “capable of breaking today’s encryption” and urged organizations to switch to post-quantum methods “as swiftly as possible.”

While large-scale quantum computers capable of breaking existing public-key cryptosystems remain hypothetical, the National Institutes of Standards and Technology has noted that some experts expect such devices within the next decade, and Europol‑led advisory groups point to a credible 10 to 15-year timeline for post‑quantum risks. For privacy professionals, these warnings signal that crucial compliance functions — proving consent, preserving data integrity, demonstrating lawful processing — must remain viable even after cryptography changes.