Executing code can be dangerous. This thesis describes a scheme for protecting the user by constraining the behavior of an executing program. We introduce Naccio, a general architecture for constraining the behavior of program executions. Naccio consists of languages for defining safety policies in a platform-independent way and a system architecture for enforcing those policies on executions b...

This work introduces a new approach to code safety. We present Naccio, a system architecture that allows a large class of safety policies to be expressed in a general and platform-independent way. Policies are defined in terms of abstract resource manipulations. We describe mechanisms that can be used to efficiently and conveniently enforce these safety policies by transforming programs. We are...

This paper presents a process for the stepwise refinement of safety code assertions from identified system hazards. The code assertions are intended for use in system safety verification. The development of the safety code assertions increases the feasibility of using code verification tools such as SPARK Examiner in the safety verification of large software-intensive systems. The process is de...

Software language descriptions comprise several heterogeneous interdependent artifacts that cover different aspects of languages (abstract syntax, notation and semantics). The dependencies between those artifacts demand the simultaneous adaptation of all artifacts when the language is changed. Changes to a language that do not change semantics are referred to as refactorings. This class of chan...

Low probability of detection (or covert) communication refers to the scenario where information must be sent reliably to a receiver, but with low probability of detection by an adversary. Recent works on the fundamental limits of this communication problem have established achievability and converse bounds that are asymptotic in the block length of the code. This paper uses Gallager’s random co...