Examples for enhancements for cloud security standards

Design and implementation in line with Service Model Patterns

This section describes how the details about the Service Model can be requested and provided:

  • The Security Measure text below is an example how cloud security standards can request Cloud Service Providers (CSP) to deliver the Service Model Patterns. The measure text also stipulates minimal requirements about the content of the Patterns (what needs to be addressed and described).
  • The Implementation Guidance below provides further explanations and provides details regarding the Service Model. More importantly, the structure of the Patterns is defined (in Table 2). In this example, combining a) user groups (UG), b) purposes and activities (PA) and c) tools and means used for this (TM) in each Pattern is considered to be sufficient for characterizing the cloud service’s Service Model. Patterns are created by choosing one element from a) the list of user groups (UG), b) the list of purposes and activities (PA) and c) the list of tools and means used for this (TM). The Cloud Service Provider (CSP) characterizes the cloud service under consideration by combining elements from the lists and forming statements accordingly. At the end of Table 2, an example is given for one Pattern (sentence) that help characterizing a specific cloud service. Such sentences are expected to be delivered as user’s guide by the Cloud Service Providers (CSP).
  • It is important to note that different cloud security standards can develop different solutions. The required content, the structure and format my differ between them. That’s why this Zero Outage Industry Standard only describes the concept and provides example. Nevertheless, each standard shall define unique requirements to be met by the Cloud Service Providers (CSP).
  • A Rationale is also given which shall explain why this Security Measure (requirement for the Cloud Service Provider, CSP) is defined and part of the cloud security standards.

Note that the Security Measure text is formulated as a statement and not as a requirement using shall, should etc. in order to avoid different interpretations of the level of bindingness.

The remaining part of this section provides an example specification requiring the Cloud Service Provider (CSP) to deliver Service Model patterns.

Security Measure: Design and implementation in line with Service Model Patterns The cloud computing service is designed and implemented according to predefined Service Model Patterns. These Patterns describe characteristics of the cloud computing service’s Service Model. As a minimum the following is defined: The Patterns identify all user groups (or types of users) accessing the cloud’s resources (e.g., customers, CSP’s administrators) and characterize the purpose and activities (e.g., end-user access, cloud management, administration of IT infrastructure) as well as the means used for this (e.g., Internet network connectivity, self-service portal, CSP’s admin infrastructure).

Implementation guidance:

  • The Patterns are simply a set of rules or of statements that characterize a specific implementation.
  • This security measure requires a) the definition of Service Model Patterns and b) that these Patterns are adhered to during design, implementation and for planning the cloud’s operations.
  • Service Models are characterized by a specific division of work within the IT stack. Service Models are about distributing responsibility. This in turn requires having the necessary accesses and rights to perform actions. As a result, a Service Model describes “which party or user group is doing what”. The Patterns reflect this.
  • E.g., in case of IaaS and PaaS, the creation and management of the VMs can be performed by the CSP or by its customers. In case of SaaS, this is performed by the IT service provider (CSP). Implementing connectivity and granting accesses is a security topic. That’s why, the Patterns describe a) what party b) does what c) by using what. By implementing the Patterns, it is ensured that connectivity, accesses etc. are intentionally designed and implemented in a secure way.
  • The identification of means and other IT services that are combined with the cloud computing core service and their characteristics ensures that configurations that are insecure are not used.
  • Table 3 shows how Service Model Patterns can be built. The table shows lists of three factors. A Pattern is created by combining items from the three lists. Each Pattern has the following structure: A “user group” is enabled and responsible for performing “an activity” and uses “tools and means” for this. The activities (PAx, refer to Table 3) can be combined in one pattern depending on the distribution of responsibilities between the user groups (UGx).
  • Other circumstances can be added as appropriate.
  • Create as much policies as required to describe the Service Model being implemented.

Table 3: Building a Service Model Pattern that characterizes a Cloud Service Model by combining three factors (number of factors as well as the factors are examples and illustrative only)

  • The Service Model Patterns are used during design, implementation and for planning the cloud’s operations. Whenever required, appropriate security measures are implemented to implement the Patterns.
  • Implementing a specific Service Model also entails technical modifications.
  • The Service Model Pattern are part of the service description document. The structure of the Patterns described above eases the comparison of different cloud computing services.

Rationale: Different Service Models are characterized by a specific division of work. This in turn requires having the necessary accesses and rights to perform actions. By implementing the Service Model Patterns, it is ensured that connectivity, accesses etc. are intentionally designed, implemented in a secure way and in line with the Service Model. Moreover, user organizations know the activities they are still responsible for so that they can prepare accordingly.