The Post-Quantum Web Arrived as a Platform Setting

Nearly half, one default

A new longitudinal study tested more than two billion TLS handshakes across one million domains from 11 global vantage points. By March 2026, 49.22 percent of its stable panel negotiated a hybrid post-quantum key exchange by default. Every one of those default negotiations selected the same construction, X25519MLKEM768. The web appears to be moving quickly, but the route is narrower than the policy calendars suggest.

The platforms moved first

The paper attributes 93.92 percent of observed post-quantum TLS deployment to configurations likely managed by infrastructure providers. Cloudflare and Fastly alone account for nearly 70 percent. Owner-managed services, including many government domains, remain mostly classical. This changes how migration progress should be read: a high aggregate percentage may describe one upstream platform decision repeated across thousands of customers, while slower institutions still face their own software, procurement and legacy-system work.

A safer handshake can keep old baggage

The hybrid exchange added a predictable number of bytes but no meaningful median latency in the measured public-web setting. At the same time, provider-managed post-quantum domains often retained older protocol versions and deprecated cipher support. The result connects engineering, policy and market power. Cryptographic infrastructure concentration can accelerate protection at remarkable speed, yet it can also obscure who made the change, which services inherited it and how much of the harder migration remains unfinished.