# COS – Communication Security

- Web page: https://c5.patrickscheid.de/en/cos/

- [COS-01 Technical Safeguards](https://c5.patrickscheid.de/en/cos-01/index.html.md): 4 sub-criteria (3 basic, 1 additional), with customer criteria, changed since C5:2020
- [COS-02 Security Requirements for Connections in the Cloud Service Provider's Network](https://c5.patrickscheid.de/en/cos-02/index.html.md): 1 sub-criterion, changed since C5:2020
- [COS-03 Monitoring of Connections in the Cloud Service Provider's Network](https://c5.patrickscheid.de/en/cos-03/index.html.md): 5 sub-criteria (5 basic), with customer criteria, changed since C5:2020
- [COS-04 Cross-Network Access](https://c5.patrickscheid.de/en/cos-04/index.html.md): 3 sub-criteria (2 basic, 1 additional), with customer criteria, unchanged since C5:2020
- [COS-05 Networks for Administration](https://c5.patrickscheid.de/en/cos-05/index.html.md): 3 sub-criteria (2 basic, 1 additional), changed since C5:2020
- [COS-06 Separation of Data Traffic in Jointly Used Network Environments](https://c5.patrickscheid.de/en/cos-06/index.html.md): 2 sub-criteria (1 basic, 1 additional), with customer criteria, changed since C5:2020
- [COS-07 Documentation of the Network Topology](https://c5.patrickscheid.de/en/cos-07/index.html.md): 4 sub-criteria (4 basic), changed since C5:2020
- [COS-08 Policies for Data Transmission](https://c5.patrickscheid.de/en/cos-08/index.html.md): 2 sub-criteria (2 basic), with customer criteria, changed since C5:2020

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Source: BSI C5:2026, machine-readable edition v1.0.1, © Federal Office for Information Security (BSI) 2026, reproduced unchanged under CC BY-ND 4.0 (https://creativecommons.org/licenses/by-nd/4.0/). Change notes: BSI C5:2026 Changelog, © BSI 2026, CC BY-ND 4.0. Unofficial presentation, not affiliated with BSI.