Penetration testing is a simulated attack; that helps to identify the type of resources exposed to the outer world, the network security risk involved in it, the possible types of attacks and the prevention of these attacks. Hence, a professional penetration testing service is invaluable for every organization to assess how a malicious user can exploit the security vulnerabilities.

Black Box Penetration Testing

This test is carried out with zero knowledge about the network. The tester will not have access to any of the client’s applications, network and internal information. This is the most authentic testing, which is done to demonstrate how a hacker with no inside knowledge of the organization can compromise your organization’s cybersecurity. Here, the tester may use the publicly available information over the internet or can acquire knowledge using penetration testing tools or social engineering techniques.

Advantages of Black Box Testing

Black Box testing is not very comprehensive testing, but it helps you achieve the user expectation from software or application. Listed below are some advantages of Black Box testing.

• Tester can be non-technical and do not require detailed functional knowledge of the system.
• Tests are done from the user’s point of view
• It helps to identify the gaps in the functional specifications
• As the tester and developer are independent of each other, the test is stable and unbiased.
• Test cases can be designed as soon as the functional specifications are ready, without having to wait for the development completion.
• Test case formation is usually faster in black box testing

Techniques used in Black Box Testing

1. Equivalence Partitioning: In this technique, the tester partitions the input values to the system or application that are likely to exhibit similar behaviour. Thus, instead of using every input value, the tester can select one from each group or class to design the test cases.
2. Boundary Value Analysis: In this technique, the boundary values are given importance in testing as these values are the most prone to issues in an application.
3. Decision Table Testing: In this technique, the tester tests the system behaviour for different input combinations. It considers various test case possibilities in a decision table format, where each condition is checked and fulfilled.
4. State Transition Testing: In this technique, the testers identify the state transition mechanism to design the test cases. This is used to observe the behaviour of the application/system for different input conditions (both positive and negative) passed in a sequence.
5. Use Case Testing: Test cases can be defined as an interaction between user and application. In the Use Case Testing technique, the testers identify the test cases from the beginning to the end of the system on a transaction-by-transaction basis.

Types of Black Box Testing

1. Functional Testing: Functional Testing is done based on the business requirement. It checks whether all the functionalities and features associated with the application are in conformance with the required specifications, rather than testing the underlying code. It mainly checks for the missing functionalities and incorrect specifications.
2. Non-functional Testing: Non-functional testing tests the software, application or system for its non-functional requirements like scalability, usability and performance. It checks how the system operates rather than the specific behaviours.
3. Regressive Testing: Regressive testing is the repetition or re-execution of functional and non-functional testing to ensure that the existing functionalities are not changed due to code modifications.

White Box Penetration Testing

This test is called complete knowledge testing and is used to check the robustness of the network in a specific environment, where the security information cannot be strictly controlled. The aim of this test is to ensure that the system can withstand security threats, even when the hacker has access to some of the security information. Testers are given full information about the target infrastructure like the host IP address, domains owned, applications used, network diagrams, security defences like IPs or IDs in the network, etc.

Advantages of White Box Penetration Testing

White Box testing is comprehensive testing that tests for the internal structures or workings of an application. The main advantages of white box testing include:

• Testing is more comprehensive as all code paths are usually covered.
• Testing can be commenced early in the Software Development Life Cycle (SDLC) even before the GUI is ready.
• It helps to optimize the program by removing the extra lines of codes.
• As internal knowledge is required for testing, maximum coverage can be obtained.
• Various hidden defects can be extracted during white box testing.

Types of White Box Testing

1. Unit testing: Unit testing is the process of testing the individual units or components of source code for successes and failures. This testing is used to uncover the issues within a specific feature and ensures that each component is working as anticipated.
2. Integration testing: The Integration testing process tests integration between the software modules. In this type of testing, the individual components are combined or integrated into a group and tested together. This is done to check the compliance of the system or software with the specified functional requirements.
3. Regressive testing: Regressive testing tests whether all the previously developed and tested software/application still functions even after a code change. It is used to make sure that the updates and changes made in the previous testing have not made severe impacts on the software.

Techniques used in White Box Testing

1. Statement Coverage: In this technique, test cases are derived based on the structure of the code. Every executable statement in the source code is executed at least once.
2. Branch Coverage: In this technique, the tester finds out the minimum number of paths that ensure all the edges are covered. It helps in validating all the branches in the code and makes sure that none of the branches leads to abnormal behaviour.
3. Path Coverage: This is a powerful and comprehensive technique that covers all the paths of the program. In this technique, every statement in the program is tested at least once.

Summing up,

we can say that you cannot substitute white box testing for black box testing and vice-versa. Each testing has a specific purpose and function in the Software Development Life Cycle. Used together, White Box and Black Box testing unveil the maximum number of vulnerabilities and bugs in the software or application. Also, there are so many other types of software testing options for organizations and individuals. So, it is important to verify your project needs before selecting a quality testing service.