Clarify requirements & constraints
- Purpose: analytics on EU personal data in US
- Data types, retention, acceptable risk, latency, third parties, regulatory constraints (GDPR, EDPB guidance)
High-level architecture
- EU ingestion zone (edge): collect + validate
- Minimize & pseudonymize in EU (tokenize or one-way hashing with salt stored in EU KMS)
- Encrypted transfer channel (TLS 1.3 + mTLS) to US analytics zone
- US analytics holds only pseudonymous encrypted identifiers; re-identification keys remain in EU HSM/KMS under strict access controls
- Results export: aggregated/less-identifiable summaries back to EU
Contractual & legal controls
- Execute SCCs with US processors + DPIA-backed Transfer Impact Assessment
- Include EU SCCs + supplementary measures: local encryption, key residency, narrow access clauses, breach notification SLAs, audit rights
- Maintain records of processing activities (RoPA) and Data Processing Agreements
Technical controls
- Pseudonymization: deterministic tokenization for analytics joins; salt/key never leaves EU
- Encryption: envelope encryption; data-at-rest AES-256, keys in EU HSM/KMS; keys never exported
- Access control: least privilege, role-based access, just-in-time elevation, MFA
- Logging & monitoring: immutable audit logs, SIEM, alerting for anomalous exports
- Data minimization: collect only attributes needed; apply field-level masking, sampling, retention TTLs, automated deletion workflows
DPIA & documentation
- DPIA sections: purpose, lawful basis, risk assessment, transfer impact, mitigation, data flow diagrams, stakeholders, retention, DSAR handling
- Transfer Impact Assessment mapping access, US govt access risk, and supplementary measures
Operationalization & evidence for auditors
- Implementation artefacts: SCCs, DPIA, RoPA, technical design docs, network diagrams
- Controls evidence: KMS/HSM configuration exports, key policies, access control lists, IAM role change history, SIEM logs, data flow captures, encryption-at-rest proofs (snapshots)
- Processes: runbooks for key rotation, incident response, DSARs; change control tickets; periodic privacy/security assessments and penetration test reports
- Automation: infra-as-code templates, CI/CD pipelines with policy-as-code (OPA), automated retention enforcement
- Audit cadence: quarterly control self-assessments, annual external audits + ad-hoc SCC audits; produce signed attestation reports and sample logs (redacted) for auditors
Why this works: combines legal (SCCs + TIA), strong technical isolation of re-identification capability in EU, minimization, and operational evidence to demonstrate continuous compliance.
