cloud-provider-assessment

Cloud Service Provider Privacy Assessment

Overview

Cloud service providers present unique privacy assessment challenges due to shared responsibility models, multi-tenancy architectures, global infrastructure, and the abstraction of physical processing locations. GDPR Article 28 obligations apply fully to cloud processing relationships, but the assessment approach must account for cloud-specific characteristics.

ISO/IEC 27018:2019 provides the international standard for protecting personally identifiable information (PII) in public clouds, supplementing ISO 27001 with cloud-specific privacy controls. The Cloud Security Alliance (CSA) STAR program provides a cloud-specific security assurance framework. SOC 2 Type II with the Privacy trust services criterion addresses personal data handling controls.

At Summit Cloud Partners, cloud providers undergo enhanced assessment incorporating these cloud-specific frameworks alongside standard vendor due diligence.

Cloud Service Models and Privacy Implications

IaaS (Infrastructure as a Service)

Aspect	Controller Responsibility	Provider Responsibility
Data encryption at rest	Configure and manage keys	Provide encryption infrastructure
Access management (app level)	Define and manage	Provide IAM platform
Network security (app level)	Configure security groups, firewall rules	Provide network infrastructure
Physical security	None	Full responsibility
Patch management (OS)	Controller (or managed service)	Hypervisor and below
Data backup	Configure and manage	Provide backup infrastructure
Incident detection (app)	Application-level monitoring	Infrastructure-level monitoring

PaaS (Platform as a Service)

Aspect	Controller Responsibility	Provider Responsibility
Application code security	Full responsibility	None
Data handling in application	Full responsibility	None
Runtime and middleware	Limited — configuration only	Manage platform components
OS and infrastructure	None	Full responsibility
Platform security patching	None	Full responsibility
Identity management	Configure	Provide identity platform

SaaS (Software as a Service)

Aspect	Controller Responsibility	Provider Responsibility
Data entered by users	Determine what data to process	Process per controller instructions
Application security	None (except configuration)	Full responsibility
Infrastructure security	None	Full responsibility
Data portability	Define export requirements	Provide export functionality
Data deletion	Request deletion	Implement deletion per DPA
Access configuration	Configure user roles	Provide RBAC platform

Assessment Framework

Domain 1: Data Residency and Sovereignty

Assessment Questions:

#	Question	Expected Evidence
1.1	In which regions/availability zones will personal data be stored at rest?	Architecture documentation specifying data storage locations
1.2	Can the controller restrict processing to specific geographic regions?	Configuration documentation showing region-locking capability
1.3	Are there any circumstances where data may be processed outside the selected region?	Disclosure of any cross-region processing (DR, support, analytics)
1.4	Where is metadata and telemetry data stored?	Often stored in provider's home jurisdiction — must be disclosed
1.5	Where do support staff access data from?	List of countries from which support personnel may access data
1.6	What government access or disclosure obligations apply in processing jurisdictions?	Legal analysis of government access powers per EDPB Recommendations 01/2020

Domain 2: Multi-Tenancy and Data Isolation

#	Question	Expected Evidence
2.1	How is tenant data isolated from other customers' data?	Architecture documentation — logical/physical separation details
2.2	Are encryption keys unique per tenant?	Key management architecture documentation
2.3	Can one tenant's operations affect another tenant's data?	Side-channel and cross-tenant risk assessment
2.4	How are shared infrastructure components secured?	Hypervisor security, shared storage controls
2.5	What tenant isolation testing has been performed?	Penetration test results covering cross-tenant attacks

Domain 3: ISO 27018 Cloud Privacy Controls

ISO/IEC 27018:2019 extends ISO 27001 with cloud-specific PII protection controls:

Control	Requirement	Assessment Check
A.1	PII processor consent — process only per controller instructions	Verify contractual terms and processing boundaries
A.2	Purpose limitation — no processing beyond controller purpose	Review processing scope documentation
A.3	Use for marketing — no use of PII for marketing without consent	Confirm no data monetization or marketing use
A.4	Notification — notify controller of government access requests	Verify government access notification process
A.5	Disclosure — document all disclosures of PII	Review disclosure logging mechanism
A.10	Return, transfer, and disposal — secure data handling at termination	Verify deletion procedures and certification
A.11	Confidentiality — binding confidentiality obligations on personnel	Verify personnel agreements cover cloud-specific risks
A.12	Sub-contracting — notification of sub-processor engagement	Verify sub-processor management per Art. 28(2)

Domain 4: CSA STAR Assessment

The Cloud Security Alliance STAR (Security, Trust, Assurance, and Risk) program provides three levels:

Level	Description	Assessment Method
Level 1: Self-Assessment	Provider completes CSA Consensus Assessments Initiative Questionnaire (CAIQ)	Review self-assessment for completeness and substantiation
Level 2: Third-Party Audit	Independent audit against CSA Cloud Controls Matrix (CCM)	Review audit report, scope, and findings
Level 3: Continuous Monitoring	Real-time monitoring of control effectiveness	Review continuous monitoring dashboard and alerts

Key CCM Control Domains for Privacy:

Domain	Controls	Privacy Relevance
DSP (Data Security & Privacy)	DSP-01 through DSP-19	Data classification, retention, inventory, privacy by design
GRC (Governance, Risk, Compliance)	GRC-01 through GRC-08	Governance framework, risk assessment, policy management
IAM (Identity & Access Management)	IAM-01 through IAM-16	Access control, credential management, MFA
SEF (Security Incident Management)	SEF-01 through SEF-08	Incident response, breach notification

Domain 5: SOC 2 Type II Privacy Criterion

The AICPA Trust Services Criteria Privacy criterion evaluates:

Criterion	Area	Assessment Focus
P1	Notice	Provider discloses privacy practices to controllers
P2	Choice and consent	Controller can configure privacy settings
P3	Collection	Data collection limited to stated purposes
P4	Use, retention, disposal	Processing per instructions; retention per DPA; certified deletion
P5	Access	Controller can access and retrieve their data
P6	Disclosure to third parties	Sub-processor disclosure and management
P7	Security for privacy	Technical controls protecting PII
P8	Quality	Data integrity and accuracy controls
P9	Monitoring and enforcement	Compliance monitoring and breach response

Domain 6: Shared Responsibility Model Mapping

Document the shared responsibility boundary for every control domain:

Control Domain	Controller Responsibility	Provider Responsibility	Gap/Risk
Data classification	Classify data before upload	Provide classification tools	[Gap?]
Encryption key management	[Depends on model]	[Depends on model]	[Gap?]
Access control (application)	[Depends on model]	[Depends on model]	[Gap?]
Vulnerability management	[Depends on model]	[Depends on model]	[Gap?]
Incident detection	[Depends on model]	[Depends on model]	[Gap?]
Data backup	[Depends on model]	[Depends on model]	[Gap?]
Compliance reporting	[Depends on model]	[Depends on model]	[Gap?]

Assessment Scoring

Domain	Weight	Score (1-5)	Weighted
Data residency and sovereignty	20%
Multi-tenancy and isolation	20%
ISO 27018 compliance	15%
CSA STAR level	15%
SOC 2 Privacy criterion	15%
Shared responsibility clarity	15%
TOTAL	100%

Key Regulatory References

• GDPR Article 28 — Controller-processor relationship applies fully to cloud
• GDPR Article 32 — Security measures including cloud-specific controls
• ISO/IEC 27018:2019 — Code of practice for protection of PII in public clouds
• ISO/IEC 27017:2015 — Code of practice for information security controls for cloud services
• CSA Cloud Controls Matrix (CCM) v4.0 — Cloud security control framework
• EDPB Recommendations 01/2020 — Supplementary measures for cloud transfers
• ENISA Cloud Computing Risk Assessment (2009, updated) — EU cloud risk framework