A security firm is writing a response to an RFP from a customer that is building a new network based software product. The firm's expertise is in penetration testing corporate networks. The RFP…

Code review involves systematic examination of the source code to identify security flaws, logic errors, and unsafe coding patterns that dynamic testing alone may miss, ensuring comprehensive coverage of all implemented behaviors.

Penetration testing is primarily a black-box or limited-knowledge technique focused on exploiting externally visible attack surfaces, not on exhaustively verifying all internal code behaviors.

Grey box testing provides only partial internal knowledge, which is insufficient to guarantee that all possible behaviors are identified and tested as the RFP explicitly requires.

Code signing is a mechanism for verifying software authenticity and integrity after build, not a testing methodology that evaluates functional or security behaviors of the product.

White box testing gives testers full knowledge of internal architecture, source code, and data flows, enabling them to design test cases that exercise every code path and satisfy the RFP requirement to test all possible product behaviors.