Privacy Implementation Guide

ARPA can expose a high-value graph of agents, principals, operators, beneficiaries, delegations, capabilities, incidents and governance relationships. Privacy therefore applies not only to record contents but also to searchability, graph reconstruction, query telemetry, status probing and historical resolution.

Data minimization and disclosure classes

Publish only data required for a relying decision. Keep principals, beneficiaries, confidential delegation terms, detailed evidence and execution records behind authorized resolution. Every deployment should classify records and relationships as public, ecosystem-visible, pairwise/context-scoped, tenant-specific, or confidential according to the sensitivity of the association.

Unauthenticated discovery must return only content explicitly classified for public disclosure. Authenticated access does not itself authorize broader disclosure: policy must bind caller, purpose, audience and retention expectations.

Correlation controls

Where stable identifiers or public relationships can enable cross-context linkage, use pairwise/context-scoped identifiers or an equivalent anti-correlation mechanism. Avoid publishing edges that reveal beneficiaries, protected professional relationships, sensitive organizational structure, security topology, or confidential commercial associations when a scoped assertion or derived decision is sufficient.

Query and enumeration privacy

Treat list/search endpoints, status lookups and historical queries as privacy-sensitive surfaces. Apply bounded pagination, rate controls, query minimization and auditable access. Higher-assurance deployments should detect systematic enumeration and distinguish ordinary relying-party resolution from bulk graph extraction.

Evidence and historical state

Execution receipts should use digests, encrypted references and scoped evidence packages rather than embedding raw protected inputs or outputs. Point-in-time reconstruction must respect retention and legal constraints without erasing the existence of terminal lifecycle events needed for accountability. Access to historical evidence should itself be auditable.

Deployment evidence

A privacy claim should be backed by a data-flow inventory, disclosure matrix, retention schedule, access-control tests, enumeration-abuse tests and evidence-access logs. Repository conformance proves protocol behavior, not jurisdiction-specific privacy compliance.

See Governance and Security Assurance and the 2026-08-16 RAHP audit.