What are white-box testing methodologies capable of assessing directly?

White-box testing methodologies are designed to evaluate the internal structures or workings of an application. This type of testing allows the tester to have complete knowledge of the system, including the source code, design documents, and architecture. Therefore, it can directly assess code quality and identify security vulnerabilities.

The focus of white-box testing is on the logic, structure, and flow of the code, enabling testers to find issues like insecure coding practices, potential security flaws, and inefficiencies within the code itself. By examining paths through the code, white-box testing can effectively highlight areas where the application may be vulnerable to attacks or may not adhere to best coding practices.

In contrast, the other options touch upon aspects that are not primarily within the scope of white-box testing. While network speed and efficiency, system performance, and vulnerabilities in encryption methods may be assessed through other testing methodologies or approaches, they do not directly correlate with the primary aim of white-box testing, which centers around the internal code and logic of the application.