The designer must realize the architect's vision as a meaningful design. The designer takes over from the architect. The designer has to interpret the architect's conceptual vision and turn it into a logical structure that can be engineered to create a real building. The architect is an artist and visionary, but the designer is an engineer (Sherwood, Clark, & Lynas, 2005).

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In the world of business computing and data communications, this design process is often called 'systems engineering'. It involves the identification of the logical architectural elements of an overall system. This view models the business as a system, with system components that are themselves sub-systems. It shows the major architectural security elements in terms of logical security services, and describes the logical flow of control and the relationships between these logical elements. It is therefore also known as the logical security architecture (Sherwood, Clark, & Lynas, 2005).

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The logical security architecture is concerned with:

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What?  Business information is a logical representation of the real business. It is this business information that needs to be secured;

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Why?  Specifying the security policy requirements (high-level security policy, registration authority policy, certification authority policy, physical domain policies, logical domain policies, etc.) for securing business information;

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How?  Specifying the logical security services (entity authentication, confidentiality protection, integrity protection, non-repudiation, system assurance, etc.) and how they fit together as common re-usable building blocks into a complex security system that meets overall business requirements;

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Who?  Specifying the entities (users, security administrators, auditors, etc.) and their inter-relationships, attributes, authorized roles and privilege profiles in the form of a schema;

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Where?  Specifying the security domains and inter-domain relationships (logical security domains, physical security domains, security associations);

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When?  Specifying the security processing cycle (registration, certification, login, session management, etc) (Sherwood, Clark, & Lynas, 2005).

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Source:

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Sherwood, J., Clark, A., & Lynas, D. (2005). The Designer's View. In J. Sherwood, A. Clark, & D. Lynas,

        Enterprise  Security Architecture (p. 38). San Francisco: CMP Books.

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