BSI C5:2020 CRY-01 — Policy for the use of encryption procedures and key management

What this control requires

Documents encryption and key management policies per SP-01, specifying strong encryption, risk-based usage, and secure key lifecycle management. Aligns with data classification and legal requirements to protect cloud customer data confidentiality and integrity.

In plain English

Documents encryption and key management policies per SP-01, specifying strong encryption, risk-based usage, and secure key lifecycle management. In practice, this means you can prove you risk protection-level controls on a defined cadence.

Why it matters

BSI C5 is the default cloud-security baseline German public-sector buyers and many DAX-listed enterprises expect; gaps here directly block procurement in the DACH region and frequently appear as must-have items in EU public-tender documents.

This control is rated high. Auditors expect a named owner, a remediation SLA, and a tooling artefact that evidences continuous operation.

What an auditor looks for

A C5 attesting auditor (under ISAE 3000 / IDW PS 860) tests both the design and — for a Type 2 — the operating effectiveness over the attestation period. For each criterion they look for both the Basic and any in-scope Additional objectives.

Within Cryptography & Key Management, the assessor will trace your implementation back to the catalogue reference (Criterion CRY-01) and look for objective evidence on the latest two assessment cycles.

How to implement

Cloud Posture

CSPM. Run Wiz / Prisma / Defender for Cloud / Security Command Center over every account; auto-ticket findings above your accepted-risk threshold.

Policy Management

Docs. Keep each policy in version-controlled Markdown alongside the code that implements it; ship a signed PDF snapshot at each annual review and link the SHA into the SoA.

Operational checklist

• Risk. Document the trigger, the owner and the cadence.
• Confidentiality. Document the trigger, the owner and the cadence.
• Protection. Document the trigger, the owner and the cadence.
• Data. Document the trigger, the owner and the cadence.
• Policy. Document the trigger, the owner and the cadence.
• Scope: protection, cloud customer data, key management.

Evidence to collect

• Policy Document. A signed and version-controlled policy / standard / procedure document.
• Infra Scan. Continuous infrastructure-posture telemetry — AWS Config, Azure Policy compliance, GCP Organisation Policy, Wiz / Prisma findings.

Signed policy or standard documents the safeguard. Focus: Policy for the use of encryption procedures and key management.

Common pitfalls

• Treating CSPM findings as a backlog instead of a hot queue: findings older than the policy SLA accumulate until the auditor asks why.
• Policies that no engineer has read; the version in Confluence drifts from the version that's actually being enforced.

How it maps to other frameworks

Computed from shared tags, control component and key-operation subjects — handy when you are reconciling controls across an audit.

• ISO/IEC 27001:2022 A.8.24 — Use of cryptography
• SOC 2 (2017 TSC) P2.1 — Communication of Data Subject Choices and Consequences
• India DPDP Act 2023 PD-001 — Data Protection Impact Assessment Programme
• NIST SP 800-171 Rev. 3 3.13.15 — Session Authenticity
• NIST SP 800-53 Rev. 5 SC-12(2) — Symmetric Keys

Related controls in BSI C5:2020

• Criterion CRY-04 — Secure key management
• Criterion AM-06 — Asset Classification and Labelling
• Criterion CRY-02 — Encryption of data for transmission (transport encryption)
• Criterion AM-03 — Commissioning of Hardware
• Criterion HR-02 — Employment terms and conditions
• Criterion PI-01 — Documentation and safety of input and output interfaces

References

• Bundesamt für Sicherheit in der Informationstechnik (BSI) — BSI C5:2020
• Catalogue identifier: Criterion CRY-01

Topics: governance riskdata protectionkey managementcloud postureencryption at restpolicy management