Tools used for Black Box testing:

Many tool vendors have been producing tools for automated black box and automated white box testing for several years. The basic functional or regression testing tools capture the results of black box tests in a script format. Once captured, these scripts can be executed against future builds of an application to verify that new functionality hasn't disabled previous functionality.
Graph Based Testing Methods

Software testing begins by creating a graph of important objects and their relationships and then devising a series of tests that will cover the graph so that each objects and their relationships and then devising a series of tests that will cover the graph so that each object and relationship is exercised and error is uncovered.
Error Guessing

Error Guessing comes with experience with the technology and the project. Error Guessing is the art of guessing where errors can be hidden. There are no specific tools and techniques for this, but you can write test cases depending on the situation: Either when reading the functional documents or when you are testing and find an error that you have not documented.
Equivalence Partitioning

Equivalence partitioning is a black box testing method that divides the input domain of a program into classes of data from which test cases can be derived.

EP can be defined according to the following guidelines:

• If an input condition specifies a range, one valid and one two invalid classes are defined.
• If an input condition requires a specific value, one valid and two invalid equivalence classes are defined.
• If an input condition specifies a member of a set, one valid and one invalid equivalence class is defined.
• If an input condition is Boolean, one valid and one invalid class is defined.

Comparison Testing

There are situations where independent versions of software be developed for critical applications, even when only a single version will be used in the delivered computer based system. It is these independent versions which form the basis of a black box testing technique called Comparison testing or back-to-back testing.
Orthogonal Array Testing

The Orthogonal Array Testing Strategy (OATS) is a systematic, statistical way of testing pair-wise interactions by deriving a suitable small set of test cases (from a large number of possibilities).