Gray Box
Candlefocus EditorThe ‘boxes’ used to refer to different levels of knowledge are used to describe the level of knowledge a tester has of the application they're testing. With white box testing, the tester has full knowledge of the application's internal workings and with black box testing, the tester only knows the input and output requirements. The gray box technique sits somewhere in between.
Unlike a black box test, in which the tester does not know anything about the internal structure or code, the tester in a gray box test has partial knowledge of the internal workings of the system; it's a supplemental technique which combines aspects of code-level testing with system-level functional testing. The tester would have knowledge of the system structure, design, coding and internal processes.
This type of testing has become increasingly important as software applications become more complex and interdependent. The tester needs to be aware of the potential vulnerabilities of these complex interconnected layers and how they interact with each other. Having some knowledge of the internal working of the system allows the tester to probe deeper and find issues before malicious hackers can.
Gray box testing also provides the tester with the understanding of the application's architecture; they can therefore better access its untested pathways and deep dive into areas that may not have been explored with other testing techniques. Furthermore, it can be used to assess the impact of implementation bugs - since the tester has a more comprehensive understanding of the application, they can assess how their actions may impact other areas of the application.
Overall, gray box testing is an important technique which both strengthens overall security of the application and ensures that proper safeguards are in place. It helps developers and testers assess and protect against malicious, deliberate attacks and implementation bugs more comprehensively than either a fully black box or white box technique could do on its own.