The methods for testing the security of a computer system or network are black box, grey box and white box penetration testing. The level of access and knowledge required to test the target system is different between the methods.
Black box testing is a method of testing that requires the tester to have no knowledge about the inner workings of the system being tested. The tester is given only the interface to the system. They are expected to use this information in order to identify security vulnerabilities. This testing is used to simulate an attacker acting without any prior knowledge of the system.
Grey box testing is a combination of black box and white-box testing. Grey box testing is a type of testing that requires the tester to have limited knowledge about the internal workings and functions of the system being tested. Grey box testing allows the tester to have limited access to information or to specific components of the system. However, they cannot see the whole system. Grey box testing can be used to simulate an insider’s actions and knowledge of the system.
White box testing allows the tester to have complete access to the internal workings and configurations of the system being tested. The tester has full access to the system including documentation and source code. White box testing can be used to verify security of systems that have been developed internally. The tester is familiar with the system and can perform more detailed tests.
Each of these types of testing is useful in different situations. A comprehensive security assessment will usually include a mix of grey box, black box and white box testing.
Black box testing can be useful in simulating an attacker’s actions, because it allows the tester the ability to view the system from an outsider’s perspective. The tester may not be able find all weaknesses or test every aspect of the system because they do not have any knowledge about the internal workings.
Grey box testing can be a compromise between white box and black box testing. It allows the tester to gain some insight into the system’s internal workings while still looking at it from an outsider’s perspective. This is useful when testing systems that have been developed internally but that are meant to be used externally. It allows the tester to spot vulnerabilities that an outsider might not be aware of.
White box testing is the most comprehensive type of testing. The tester has complete knowledge about the system’s internal workings and can thoroughly test every area of it. It may not be possible to whitebox test systems developed by third parties as the tester may not be able to access the source code and other internal components.
The three main methods for testing the security of computer systems, web applications, and networks are black box, grey, and white box. Black box testing simulates an attacker who has no knowledge of the system. Grey box testing simulates an insider with limited knowledge. White box testing involves a tester who is fully conversant with the system. Each type of testing has its strengths and weaknesses. A comprehensive security assessment will usually include a mix of all three.