# ISO/IEC 27701 A.3.26 — Use of cryptography

- Source: https://support.icompaas.com/support/solutions/articles/a_gen_iso27701_a326_9eca0ad75f-isoiec-27701-a326-use-of-cryptography
- 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.3.26 · Priority: critical · Component: Security considerations

### What this control covers

Define and implement rules for effective use of cryptography and key management. Implementation: Define cryptographic policy, key management and provide info to customers about usage. Justification: Cryptography protects confidentiality and integrity of PII.

### 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.

### Evidence to collect

-   `infra_scan` — See the iCompaas Evidence library for the canonical source for this evidence type.
-   `policy_document` — A signed, version-controlled policy stating leadership intent and the named owner.

Signed policies, procedures, and registers document the safeguard. Infrastructure posture tooling (AWS/Azure/GCP configuration, encryption, backup, logging) verifies technical enforcement. Focus: Use of cryptography.

### Quick checklist

-   Implement — Use Of Cryptography
-   Define — Use Of Cryptography
-   Provide — Use Of Cryptography

### Related articles on this site

-   [Ensure Encryption at Rest and in Transit is configured](https://support.icompaas.com/support/solutions/articles/62000234483-ensure-encryption-at-rest-and-in-transit-is-configured)
-   [Implement and Enforce a Global Dependency Usage Policy](https://support.icompaas.com/support/solutions/articles/62000234956-implement-and-enforce-a-global-dependency-usage-policy)
-   [Ensure S3 buckets have default encryption (SSE) enabled or use a bucket policy to enforce it](https://support.icompaas.com/support/solutions/articles/62000086777-ensure-s3-buckets-have-default-encryption-sse-enabled-or-use-a-bucket-policy-to-enforce-it)
-   [Ensure S3 buckets have default encryption (SSE) enabled or use a bucket policy to enforce it](https://support.icompaas.com/support/solutions/articles/62000129497-ensure-s3-buckets-have-default-encryption-sse-enabled-or-use-a-bucket-policy-to-enforce-it)