The 30-Year Ship and the 10-Year Cipher: Post-Quantum Cryptography for Maritime OT
A ship lives 20–30 years. Its public-key cryptography may not. Why maritime OT has to think about the quantum threat at the design stage — not after Q-Day.
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Most cryptographic threats ask one question: can it be broken today? The quantum-computing conversation asks a different one, in a different tense. The problem is not today — it is 20 to 30 years out, while the asset is still alive. And few assets live as long as a ship.
The lifespan of a ship and the lifespan of a cipher no longer line up
A merchant vessel's hull and automation systems typically operate for 20 to 30 years, with major technology refreshes that are rare and only partial. Yet most of what that ship exchanges over satellite today rides on RSA, elliptic-curve cryptography (ECC), and Diffie-Hellman — the public-key family that a sufficiently powerful quantum computer is expected to break within a practical time frame.
So the two lifespans no longer line up. A newbuild delivered in 2026 may still be trading around 2050, and the scenario in which public-key cryptography falters somewhere in between is no longer science fiction. Experts treat it not as fear, but as structural risk. This piece takes that structure apart on the hard ground of maritime OT.
Harvest Now, Decrypt Later — the collection has already started
The reason the threat exists already, before any quantum computer does, is HNDL (Harvest Now, Decrypt Later). An adversary captures and stores today's encrypted traffic and decrypts it retroactively once a capable quantum computer arrives. Today's ciphertext becomes tomorrow's plaintext.
Maritime data is an especially attractive target from that angle. Routes, cargo, charter parties, maintenance histories, crew records — much of it retains value decades later, and for naval or government vessels that value lasts longer still. The threat surface is already wide: one maritime SOC (Marlink) reported monitoring roughly 1,998 vessels in the second half of 2024, logging on the order of 9 billion security events and more than 10,000 malware detections.
The key is tense. Even if "when will a quantum computer arrive?" is uncertain, if the secrecy lifetime of the data you must protect today is longer than that arrival, you have to act now. That is the intuition behind Mosca's inequality.
On a ship, both X (secrecy lifetime) and Y (migration time) are unusually long. The vessel is precisely the asset for which this inequality resolves in the worst possible way.
So when? Treating uncertainty as uncertainty
Honestly: nobody knows the exact date. But a probability distribution does exist. The Global Risk Institute's annual expert survey (Michele Mosca / evolutionQ), in its 2024 edition, polled 32 global experts on the odds of a cryptographically relevant quantum computer (CRQC) capable of breaking RSA-2048:
| By year | Probability of a CRQC (RSA-2048) |
|---|---|
| 2029 | 5–14% |
| 2034 | 19–34% |
| 2039 | ~50% |
| 2044 | ~79% |
What matters is the trend. The 2024 report says the threat may be closer than previous surveys suggested. The message is not "everything breaks soon" — it is that the risk already falls within long-lived asset planning horizons. For anyone designing a 20-to-30-year asset, a 19–34% expert-response range by 2034 and roughly 50% by 2039 are already material planning signals.
The standards and regulations have already moved
Read through the lens of standards and regulatory timelines, not technology hype, the direction is unambiguous.
Government, finance, telecom, and critical infrastructure have already begun migrating. So — what about maritime?
The maritime blind spot: E26/E27 say nothing explicit about post-quantum readiness
IACS UR E26 (the ship as a whole) and E27 (in-scope onboard computer-based systems and equipment) apply through IACS member rules to covered new ships contracted for construction on or after 1 July 2024. Exact mandatory or non-mandatory applicability depends on vessel type and size under UR E26. For the computerized systems behind core functions — propulsion, steering, power generation — they set an important baseline for maritime cyber resilience.
The current E26/E27 contain no explicit requirement for post-quantum readiness or cryptographic migration planning.
E26/E27 themselves do not require a PQC transition or crypto-agility plan. A class society's rules, flag requirements, owner specifications, or contract terms may add requirements beyond the IACS minimum. For an asset that will live 20 to 30 years, that gap is not small. Regulation usually follows the threat — but the cost of that lag lands on the owner.
Why maritime OT is harder than shore-side IT
PQC migration is hard even in shore-side enterprise IT. In maritime OT it is an order of magnitude harder, for structural reasons.
The conclusion is not "swap the algorithm" — it is crypto-agility
Here the practical conclusion flips. It is not "replace RSA with ML-KEM." No one can fix today which algorithm ultimately wins, or when the next weakness surfaces. The goal is therefore not a specific algorithm, but a structure that can change algorithms — crypto-agility.
What it means in practice: the newbuild design stage is the only cheap window
By the nature of ships, retrofitting after commissioning is expensive and slow. So the cheapest place to prepare for PQC is the newbuild design and construction stage. For a ship being contracted now:
☑ Make a CBOM submission and a PQC support timeline contractual conditions on the supply chain.
☑ Design IT/OT separation and zoning (zones and conduits) so that even if cryptography falters, the blast radius is contained.
☑ Judge by asset-lifetime risk through Mosca's inequality, even where E26/E27 does not yet require it.
Whether a quantum computer arrives in 2034 or 2044, no one can promise. But the ship you contract today will sail straight through that entire band of uncertainty.
The case for preparing is not fear — it is the arithmetic of asset lifetime.
· NSA — CNSA 2.0 algorithms and timeline
· EU PQC Workstream — Coordinated Implementation Roadmap (2025-06)
· Global Risk Institute / evolutionQ — Quantum Threat Timeline Report 2024 (32-expert survey)
· CISA — Post-Quantum Considerations for Operational Technology
· MarineLink / Marlink — "Harvest Now, Decrypt Later" (maritime-specific; SOC statistics)
· IACS / ClassNK — UR E26 / E27
Owner-side maritime cybersecurity advisor covering IACS UR E26/E27 compliance, zone and conduit design, and OT/IT security architecture for commercial vessels — working across LR, ClassNK, DNV, ABS, and BV newbuilding projects.
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Quantum may still feel like a distant concept to many, but I believe the maritime industry should start preparing sooner rather than later.
ReplyDeleteShips have service lives of 20–30 years, while cryptographic technologies evolve much faster. In the age of AI-driven cyber threats, attackers do not distinguish between sea and shore. Maritime systems are becoming part of the same connected digital ecosystem, making proactive adoption of quantum-safe security an important long-term investment rather than a future option.