BSI C5:2020 PSS-05 — Authentication Mechanisms

What this control requires

Provides strong authentication mechanisms, enforcing multi-factor for privileged users and components. Ensures secure access at all interaction points, protecting cloud customer data from unauthorized access within customer environments.

In plain English

Provides strong authentication mechanisms, enforcing multi-factor for privileged users and components. In practice, this means you can prove you review cloud customer data-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 Platform & Service Security, the assessor will trace your implementation back to the catalogue reference (Criterion PSS-05) 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.

Operational checklist

• Review. Document the trigger, the owner and the cadence.
• Security. Document the trigger, the owner and the cadence.
• Data. Document the trigger, the owner and the cadence.
• Access. Document the trigger, the owner and the cadence.
• Authentication. Document the trigger, the owner and the cadence.
• Scope: cloud customer data, mechanisms, environments, management.

Evidence to collect

• Identity Scan. IAM / IdP exports — Entra ID, Okta, IAM Identity Center, Workspace directory — showing accounts, roles, MFA state and last sign-in.

Identity analytics (Okta, SailPoint, Access Analyzer) demonstrates least-privilege. Focus: Authentication Mechanisms.

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.

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.

• SOC 2 (2017 TSC) CC6.2 — Access Provisioning
• ISO/IEC 27001:2022 A.8.2 — Privileged access rights
• CIS Controls v8 14.9 — Conduct Role-Specific Security Awareness and Skills Training
• NIST SP 800-171 Rev. 3 3.13.4 — Information in Shared System Resources
• NIST SP 800-53 Rev. 5 AC-6(6) — Privileged Access By Non-Organizational Users

Related controls in BSI C5:2020

• Criterion PSS-09 — Authorisation Mechanisms
• Criterion PSS-08 — Roles and Rights Concept
• Criterion AM-05 — Commitment to Permissible Use, Safe Handling and Return of Assets
• Criterion HR-01 — Verification of qualification and trustworthiness
• Criterion IDM-03 — Locking and withdrawal of user accounts in the event of inactivity or multiple failed logins
• Criterion INQ-03 — Conditions for Access to or Disclosure of Data in Investigation Requests

References

• Bundesamt für Sicherheit in der Informationstechnik (BSI) — BSI C5:2020
• Catalogue identifier: Criterion PSS-05

Topics: identity accessprivileged accessidentity managementaccess reviewcloud posture