Binary rewriting techniques comprise confinement and diversification. The goal of confinement is to prevent undetected vulnerabilities from causing a failure in an executing application. Techniques to detect and prevent certain specific classes of vulnerabilities already exist to some extent, but often lead to a program failure state, which, in turn, leads to a denial of service. Although an attack might be prevented, these consequences are unacceptable in critical systems. GrammaTech has been researching sophisticated confinement techniques that allow applications to detect the same kinds of attacks, but continue operation (while still containing the vulnerability). Combining binary analysis to detect the potential vulnerability with static rewriting to confine the exploit, it's possible to greatly reduce and even eliminate the impact.

Analysing application binaries allows GrammaTech's rewriting tools to discover the use of potentially problematic code patterns, libraries or OS functions. The rewritten binaries have wrappers around such code to prevent erroneous behaviour. For example, function call stack usage can be instrumented to prevent stack overflow and subsequent code injection. Another example would be preventing calls to known problematic library functions such asstrcpy() from causing buffer overflow errors.

Rewriting a binary executable into a hardened version provides quality and security assurance for any version of the application-current and future versions are protected. GrammaTech's hardening tools static rewrite binaries into more secure applications.

Binary analysis and rewriting by nature doesn't require source and is version-independent. As such, IoT device manufacturers can use GrammaTech’s hardening techniques on every release of their applications, making software hardening a standard procedure in the software release process.