# BSI C5:2020 PI-01 — Documentation and safety of input and output interfaces - Source: https://support.icompaas.com/compliance/bsi-c5-2020/pi-01-documentation-and-safety-of-input-and-output-interfaces - Section: [Compliance](https://support.icompaas.com/compliance) › [BSI C5:2020 (Cloud Computing Compliance Criteria)](https://support.icompaas.com/compliance/bsi-c5-2020) › Data Processing Interfaces (PI) - Last updated: 2026-06-05 - Publisher: iCompaas, Inc. (https://www.icompaas.com) **BSI C5:2020**·Criterion `PI-01`·high·Component: **Data Processing Interfaces** ## What this control requires > Documents cloud service interfaces for customer use, ensuring secure communication via standardized, encrypted protocols per CRY-02. Provides detailed guidance for subject matter experts, maintaining interface security for cloud customer data interactions. > > — BSI C5:2020, Criterion PI-01 ### In plain English Documents cloud service interfaces for customer use, ensuring secure communication via standardized, encrypted protocols per CRY-02. In practice, this means you can prove you interfaces 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 **Data Processing Interfaces**, the assessor will trace your implementation back to the catalogue reference (Criterion PI-01) and look for objective evidence on the latest two assessment cycles. ## How to implement #### 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. #### 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 - **Interfaces.** Document the trigger, the owner and the cadence. - **Risk.** Document the trigger, the owner and the cadence. - **Documentation,.** 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. - **Scope:** cloud customer data, management. ## Evidence to collect - **Policy Document.** A signed and version-controlled policy / standard / procedure document. Signed policy or standard documents the safeguard. Focus: Documentation and safety of input and output interfaces. ## Common pitfalls - Policies that no engineer has read; the version in Confluence drifts from the version that's actually being enforced. - 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. - [**ISO/IEC 27001:2022 A.5.5** — Contact with authorities](https://support.icompaas.com/compliance/iso-27001-2022/a-5-5-contact-with-authorities) - [**SOC 2 (2017 TSC) CC2.3** — External Communication on Internal Control Matters](https://support.icompaas.com/compliance/soc-2-trust-services-criteria/cc2-3-external-communication-on-internal-control-matters) - [**CIS Controls v8 3.5** — Securely Dispose of Data](https://support.icompaas.com/compliance/cis-controls-v8/3-5-securely-dispose-of-data) - [**NIST SP 800-171 Rev. 3 3.12.3** — Continuous Monitoring](https://support.icompaas.com/compliance/nist-sp-800-171-rev-3/3-12-3-continuous-monitoring) - [**HIPAA (45 CFR Part 164) 164.308(a)(7)(ii)(A)** — Contingency Plan - Data Backup Plan](https://support.icompaas.com/compliance/hipaa/164-308-a-7-ii-a-contingency-plan-data-backup-plan) ## Related controls in BSI C5:2020 - [**Criterion HR-02** — Employment terms and conditions](https://support.icompaas.com/compliance/bsi-c5-2020/hr-02-employment-terms-and-conditions) - [**Criterion COM-01** — Identification of applicable legal, regulatory, self-imposed or contractual requirements](https://support.icompaas.com/compliance/bsi-c5-2020/com-01-identification-of-applicable-legal-regulatory-self-imposed-or-contractual) - [**Criterion PSS-12** — Locations of Data Processing and Storage](https://support.icompaas.com/compliance/bsi-c5-2020/pss-12-locations-of-data-processing-and-storage) - [**Criterion AM-06** — Asset Classification and Labelling](https://support.icompaas.com/compliance/bsi-c5-2020/am-06-asset-classification-and-labelling) - [**Criterion HR-04** — Disciplinary measures](https://support.icompaas.com/compliance/bsi-c5-2020/hr-04-disciplinary-measures) - [**Criterion SP-03** — Exceptions from Existing Policies and Instructions](https://support.icompaas.com/compliance/bsi-c5-2020/sp-03-exceptions-from-existing-policies-and-instructions) ## References - [Bundesamt für Sicherheit in der Informationstechnik (BSI) — BSI C5:2020](https://www.bsi.bund.de/EN/Topics/CloudComputing/Compliance_Criteria_Catalogue/Compliance_Criteria_Catalogue_node.html) - Catalogue identifier: `Criterion PI-01` Topics: governance riskpolicy managementcloud posture ## Related compliance guidance - [SOC 2 compliance: a practical implementation guide for cloud-native SaaS teams](https://support.icompaas.com/compliance/soc-2-trust-services-criteria): Configuration checks like this one are the technical half of a SOC 2 / ISO 27001 programme — the guide shows where they fit, what else an auditor expects, and how to evidence them. - [ISO/IEC 27001:2022 compliance: a practical implementation guide](https://support.icompaas.com/compliance/iso-27001-2022): ISO 27001 Annex A.8 (technological controls) is where cloud hardening evidence lands; the guide shows how to run the ISMS around it.