Last updated on Dec 27, 2018

Security Target (ST). An ST defines information assurance security and functional requirements for the given information system product, which is called the Target of Evaluation (TOE). An ST is a complete and rigorous description of a security problem in terms of TOE description, threats, assumptions, security objectives, security functional requirements (SFRs), security assurance requirements (SARs), and rationales. The SARs are typically given as a number 1 through 7 called Evaluation Assurance Level (EAL), indicating the depth and rigor of the security evaluation, usually in the form of supporting documentation and testing, that the product meets the SFRs.