One assignee leads the ranked field with 147 records, well ahead of the fifth-place holder at 23 and the tenth-place holder at 13. The top five assignees combined account for 285 of the 664 records in scope, or 42.9% of the field, which means a small number of filers set much of the early direction on policy decision and enforcement point claims. Below the top 10, which together hold 54.7% of records, the field thins quickly into companies with only one or two filings each.

Yes: filings rose from 44 in 2021 to 107 in 2024, a 143% increase over three years and the fastest growth period documented in this dataset. The apparent drop in 2025 and 2026 is not a real slowdown — publication typically lags filing by around 18 months, so recent years are still incomplete and will revise upward as more filings publish. 2024 is the most recent year that can be treated as a complete data point.

H04L, digital information transmission, appears in 74.4% of the 664 records, making it by far the dominant classification, followed by G06F (electric digital data processing) at 33.9% and H04W (wireless communication networks) at 17.6%. Because a single record can carry several IPC classes, these shares add up to more than 100%. Notably, G06N (AI-based computing) covers only 1.8% of records, suggesting that context-aware and adaptive policy logic is mostly claimed as conventional data processing rather than as machine learning.

The clearest gap sits around AI-framed context-aware policy scoring, since only 12 of 664 records fall under G06N despite frequent discussion of adaptive risk evaluation in the field. Continuous session reevaluation triggers, device posture attestation protocols and least-privilege token lifecycle management are also comparatively thin relative to how central they are to zero trust design. These branches sit adjacent to the dense H04L and G06F claim territory rather than inside it, which is what makes them more open to new filings.

US8452872B2, assigned to Telefonaktiebolaget L M Ericsson (Publ) and granted in 2013, covers a server acting as a policy decision point that tracks a per-user total usage quota across multiple linked connection identifiers, and that responds to quota requests from a policy enforcement point by sizing an allocation against that total and any concurrent sessions. It is tightly scoped to quota-based session allocation tied to a specific connection identifier, so it constrains designs that gate access purely on aggregate usage quota rather than blocking policy decision point architectures generally. Filings built on device posture, risk scoring or context signals rather than usage quotas sit outside its core claim language, though a full freedom-to-operate review should check dependent claims individually.