Post-Quantum Cryptography for Sovereigns: What 'Harvest Now, Decrypt Later' Actually Means
The cryptographic threat timeline is shorter than most governments realize. The data being exfiltrated today will be decryptable in 5-10 years — and the secrets it carries don't age.
Quantum computers large enough to break RSA-2048 do not exist yet. Most estimates put this 10-15 years out. This is the wrong way to think about the problem.
Harvest now, decrypt later
State-aligned adversaries are already exfiltrating encrypted traffic — diplomatic cables, defense contracts, healthcare records, intelligence assessments — with the explicit plan to decrypt it when quantum capability arrives.
Data with a 25-year confidentiality horizon — citizen biometric records, classified intelligence, treaty terms — is being harvested today. By 2035, the cryptographic primitive that protected it will be obsolete.
What sovereign-grade PQC requires
- Hybrid post-quantum + classical key exchange (avoid all-or-nothing migrations)
- FIPS 140-3 validated hardware security modules with PQC firmware support
- Customer-controlled key generation (BYOK/HYOK) with quantum-safe key ceremonies
- Migration roadmap with crypto-agility built into the platform — not bolted on
- Independent audit trail of which algorithms protect which data
CEREBRAS P5's posture
S3-SENTINEL ships with post-quantum cryptographic primitives as a first-class option, not as a roadmap item. CRYSTALS-Kyber for key exchange, CRYSTALS-Dilithium for signatures, hybridized with classical RSA/ECDSA. The cryptographic agility layer is exposed through the platform's APIs — customers can rotate algorithms without re-architecting their applications.
Key Questions
What is post-quantum cryptography?
Post-quantum cryptography (PQC) refers to cryptographic algorithms that remain secure against attacks by quantum computers. Standards are being finalized by NIST, with CRYSTALS-Kyber and CRYSTALS-Dilithium as the leading candidates.
What is harvest now, decrypt later?
A threat model where adversaries collect encrypted data today, with the plan to decrypt it later when quantum computers become capable. This makes PQC urgent even before quantum computers arrive.
What is FIPS 140-3?
FIPS 140-3 is the US government standard for cryptographic modules. It validates that the hardware and software implementing cryptography meets rigorous security requirements. CEREBRAS P5's S3-SENTINEL platform is FIPS 140-3 Level 3 certified.