The post-quantum encryption migration has a built-in casualty: a class of hardware that cannot follow. Billions of IoT devices — pacemakers, industrial controllers, satellites built a decade ago — are permanently locked out of the upgrade because the algorithms replacing today's encryption require more memory than their processors have. No firmware patch is coming. No replacement cycle will close the gap in time. Meta documented the problem from inside its own infrastructure this week, but the company is not the story — the exclusion event is.
The lockout works like this: post-quantum encryption standards require substantially more compute and memory than what they replace. A standard IoT microcontroller with 64 kilobytes of RAM cannot run the replacement algorithms, a constraint written into the hardware itself per Cloudflare's post-quantum roadmap analysis. For a modern server farm this is an engineering problem. For a pacemaker or a satellite with no over-the-air update path, it is a permanent condition.
Security researchers call the result cryptographically orphaned devices: permanently vulnerable to a future quantum computer capable of breaking today's encryption, with no patch path and no replacement cycle that aligns with the threat.
The urgency is new. Three papers published between February and March 2026 reduced the estimated qubit count required to break RSA-2048 encryption by a factor of twenty, from twenty million physical qubits down to under one million, with one architecture using quantum low-density parity-check codes estimating under 100,000. An Oratomic paper from Caltech and the Weizmann Institute went further, showing that elliptic curve cryptography, widely used for authentication, could theoretically be broken with as few as 10,000 physical qubits. Building a fault-tolerant quantum computer at that scale remains an extremely hard engineering problem, but the distance between theoretically breakable and the machine you'd need to build it is one researchers describe with words like shorter than we thought.
Google and Cloudflare moved their migration deadlines to 2029. Meta deployed post-quantum encryption across significant portions of its internal infrastructure this week. These are not organizations constrained by modest IT budgets; they are moving. IoT is not, for reasons that are not mysterious.
The embedded systems industry operates on long refresh cycles, fifteen to twenty years is common for industrial control equipment, and implanted medical devices routinely have expected operational lifespans of ten years or more. The design tradeoffs that create the lockout are the same ones that make the devices secure. A pacemaker cannot ship with an over-the-air update mechanism that could theoretically be exploited by a malicious actor; that same design choice means the device cannot receive a cryptographic update in 2026 any more than it could have in 2016. The security and the lockout are the same feature.
The enterprise migration problem is real and documented. The IoT problem is harder, longer-lived, and largely invisible to the organizations most responsible for managing it. A 2025 Gray Group survey found fewer than 30 percent of enterprises with operational technology footprints had completed even an inventory of IoT assets that would need post-quantum migration, a prerequisite to any planning. Most had not started. The window for new national security system acquisitions to meet CNSA 2.0 compliance is eight months long.
Some companies are trying to bridge the gap. Cloudflare reported in April that over 65 percent of human traffic to its network is now post-quantum encrypted on the transport layer, the pipes are largely secured even if the endpoints at each end are not. That is real progress. But a secure conversation between two endpoints requires both endpoints to participate, and the endpoints that cannot participate are not servers. They are the devices that outnumber servers by an order of magnitude and outlive them by a decade.
The mitigation menu is narrow. Network segmentation can isolate vulnerable devices behind systems capable of terminating TLS with post-quantum cryptography on their behalf. Physical replacement programs can close the gap over years rather than months. In the most sensitive contexts, some operators are treating a subset of hardware as permanently at risk, accepting the exposure rather than pretending it has been eliminated. None of these are solutions. They are ways of living with a problem that cannot be fixed.
The window between now and the end of 2026 is not the window when cryptography breaks. It is the window when the migration decisions being made right now determine what breaks later.