Simplify the following text for a Grade 15 native English-speaking person.
Original: In the case of a block cipher , it refers to a set of techniques and methods for tracing differences through the network of transformations , discovering where the cipher demonstrates non-random behavior , and extend such properties to recover the secret key .
Simplified: In the case of a block cipher , it refers to a set of techniques for tracing differences through the network of transformations , discovering where the cipher exhibits non-random behavior , and exploiting such properties to recover the secret key .