The Target of Evaluation (TOE) is a set of software, firmware, and/or hardware components that are the subject of a security evaluation process.
In essence, the TOE represents the specific product, system, or collection of components that an evaluation is focusing on to assess its security posture. It is the defined scope for the security testing and analysis.
Understanding the Target of Evaluation
The concept of a TOE is fundamental in structured security evaluation methodologies, such as Common Criteria (ISO/IEC 15408). It precisely defines what is being evaluated, setting clear boundaries to ensure the evaluation is thorough and relevant.
According to the provided reference, the TOE specifically:
- Includes: A set of software, firmware, and/or hardware components.
- Is the Subject Of: A security evaluation process.
- Defines:
- The boundaries of the product or system being tested.
- Its security functions.
- Its interfaces.
- Its implementation.
Key Components of a TOE
A TOE can be composed of various elements working together. Identifying these components is crucial for defining the TOE accurately.
Common components include:
- Software: Operating systems, applications, libraries, etc.
- Firmware: Low-level software embedded in hardware devices.
- Hardware: Physical devices like servers, network devices, smart cards, or even specific chips.
The specific combination and configuration of these elements determine the unique TOE for a given evaluation.
Why is Defining the TOE Important?
Clearly defining the TOE is critical for a successful and meaningful security evaluation. It ensures:
- Clear Scope: Evaluators know exactly what is within and outside the scope of the assessment, preventing ambiguity.
- Focused Effort: Resources are concentrated on the specific product or system intended for evaluation.
- Reproducibility: The evaluation can be understood and potentially replicated based on the defined TOE.
- Relevant Results: The findings and conclusions of the evaluation directly relate to the identified target.
Defining the TOE's Boundaries and Functions
Beyond listing components, the TOE definition details key characteristics:
| Aspect | Description |
|---|---|
| Boundaries | Physical and logical limits of the system/product under evaluation. |
| Security Functions | Specific security capabilities the TOE claims to provide (e.g., authentication, access control, encryption). |
| Interfaces | Ways users, administrators, or other systems interact with the TOE. |
| Implementation | How the security functions and interfaces are actually built and operate. |
Defining these elements provides a complete picture of what is being evaluated and how its security claims will be tested.
By acting as the defined subject and scope, the TOE ensures that a security evaluation process is focused, comprehensive within its limits, and yields relevant results regarding the security properties of that specific set of components.
