Observation

Certificate authority and key exchange protocol land within two bits of each other — 40A5F9D9 and 40A5FB89 — despite one being an organizational entity that issues credentials and the other being a stepwise algorithmic procedure. UHT appears indifferent to this ontological distinction, encoding instead the shared function of establishing trust between parties. This is the tightest cross-category pairing found in any corpus expansion so far.

Evidence

Seven cryptography entities were classified. Intra-domain Jaccard similarities measured from public-key cryptography: zero-knowledge proof 0.833, key exchange protocol 0.800, cryptographic hash function 0.615, digital signature 0.600. Cross-domain comparisons revealed zero-knowledge proof to model checking at 0.600 and to theorem proving at 0.583, rivalling the weaker intra-domain similarities. Key management to configuration item scored 0.500, while key management to change control board scored 0.444 — both sharing governance traits (rule-governed, compositional, regulated, system-integrated). The baseline management comparison collapsed to 0.077, indicating UHT does not conflate management-as-governance with management-as-snapshot.

The hex codes cluster tightly in the 40A0-40A5 range, all sharing the synthetic, intentionally-designed, processes-signals, rule-governed, digital, and economically-significant trait core. Digital signature diverges by picking up institutionally-defined and regulated traits that the more abstract concepts lack.

Interpretation

The certificate-authority/key-exchange convergence reinforces the confirmed hypothesis from session 16 that UHT organises by semantic role rather than domain vocabulary — and extends it further. Prior evidence showed cross-domain clustering of concepts sharing a role (change request to peer review at 0.857). This session shows that even within a single domain, UHT collapses structurally different entities when their functional purpose aligns. The implication is that UHT’s trait system encodes purpose and effect more heavily than form or category.

The cross-domain similarities between cryptography and formal verification (zero-knowledge proof to model checking at 0.600) are particularly notable: these fields share the concept of proving properties without exhaustive disclosure, and UHT captures that shared epistemic structure.

Action

Created COR-DOMAINEXPANSIONS-007 recording all seven cryptography entities with hex codes and cross-domain observations. Baseline CORPUS-2026-03-09-cryptography established. The certificate-authority/key-exchange convergence suggests a calibration hypothesis for a future session: whether UHT consistently collapses entity-vs-process distinctions when functional purpose aligns, testable across multiple domain pairs. The next session should consider a TRACE_GAP or CALIBRATION pass to formalise this as a testable hypothesis and check whether any corpus-log domains remain untested by calibration.