# ISO/IEC 27701 A.3.5 — Classification of information

- Source: https://support.icompaas.com/support/solutions/articles/a_gen_iso27701_a35_a833260c6e-isoiec-27701-a35-classification-of-information
- Section: [Solutions](https://support.icompaas.com/support/solutions) › [ISO/IEC 27701 (Privacy Information Management)](https://support.icompaas.com/support/solutions/c_gen_iso27701) › [Security considerations](https://support.icompaas.com/support/solutions/folders/f_gen_cgeniso27701_securityconsiderations)
- Last updated: 2026-05-30
- Publisher: iCompaas, Inc. (https://www.icompaas.com)

ISO/IEC 27701 · Control A.3.5 · Priority: high · Component: Security considerations

### What this control covers

Classify information considering PII based on confidentiality, integrity and availability needs. Implementation: Implement classification scheme and apply to PII types. Justification: Ensures appropriate handling controls per sensitivity.

### Why it matters

Encryption and key management make data unreadable to attackers and unintelligible under data-breach safe-harbour clauses — a meaningful regulatory benefit.

### How to implement

#### AWS

Default to **SSE-KMS** with customer-managed keys for S3/EBS/RDS/Secrets Manager. Use **S3 Bucket Keys** and **S3 Block Public Access** at the account level, and turn on **S3 Object Lock** on backup buckets for ransomware resilience.

#### Azure

Store secrets in **Key Vault** (HSM-backed where required) with soft-delete + purge protection; use **customer-managed keys** for Storage, SQL, and Azure Disk Encryption. Tag PII data via **Microsoft Purview**.

#### GCP

Use **Cloud KMS** with customer-managed encryption keys (CMEK) for BigQuery, GCS, and Compute. **Sensitive Data Protection** (DLP API) inspects/de-identifies PII at scale.

#### Google Workspace

Enable **client-side encryption** for Drive/Docs and turn on **Drive Labels + DLP** rules to prevent external sharing of regulated data classes.

#### On-premises

Maintain a policy library with a documented review cadence (annual minimum); store in your GRC tool with attestation tracking. Map each policy to controls so an audit pull cites the exact policy clause.

### Evidence to collect

-   `policy_document` — A signed, version-controlled policy stating leadership intent and the named owner.

Signed policies, procedures, and registers document the safeguard. Focus: Classification of information.

### Quick checklist

-   Implement — Classification Of Information
-   Ensure — Classification Of Information
-   Classify — Classification Of Information

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