Notion Of Non-interference Research Articles

Security validation of VP-based SoCs using dynamic information flow tracking

Abstract Modern System-on-Chips (SoCs) are notoriously insecure. Hence, the fundamental security feature of IP isolation is heavily used, e. g., secured Memory Mapped IOs (MMIOs), or secured address ranges in case of memories, are marked as non-accessible. One way to provide strong assurance of security is to define isolation as information flow policy in hardware using the notion of non-interference. Since, an insecure hardware opens up the door for attacks across the entire system stack (from software down to hardware), the security validation process should start as early as possible in the SoC design cycle, i. e. at Electronic System Level (ESL). Hence, in this paper we propose the first dynamic information flow analysis at ESL. Our approach allows to validate the run-time behavior of a given SoC implemented using Virtual Prototypes (VPs) against security threat models, such as information leakage (confidentiality) and unauthorized access to data in a memory (integrity). Experiments show the applicability and efficacy of the proposed method on various VPs including a real-world system.

Fighting Status Inequalities: Non-domination vs Non-interference.

Status inequalities seem to play a fairly big role in creating inequalities in health. This article assumes that there can be good reasons to fight status inequalities in order to reduce inequalities in health. It examines whether the neorepublican ideal of non-dominance does a better job as a theoretical foil for this as compared to a liberal notion of non-interference. The article concludes that there is a prima facie case for incorporating non-dominance into our thinking about public health, but that it needs to go hand in hand with a more traditional liberal ideal of non-interference.

Proof-Carrying Code Based Tool for Secure Information Flow of Assembly Programs

Problem statement: How a host (the code consumer) can determine with certainty that a downloaded program received from untrusted source (the code producer) will maintain the confidentiality of the data it manipulates and it is safe to install and execute. Approach: The approach adopted for verifying that a downloaded program will not leak confidential data to unauthorized parties was based on the concept of Proof-Carrying Code (PCC). A mobile program (in its assembly form) was analyzed for information flow security based on the concept of proof-carrying code. The security policy was centered on a type system for analyzing information flows within assembly programs based on the notion of noninterference. Results: A verification tool for verifying assembly programs for information flow security was built. The tool certifies SPARC assembly programs for secure information flow by statically analyzing the program based on the idea of Proof-Carrying Code (PCC). The tool operated directly on the machine-code requiring only the inputs and outputs of the code annotated with security levels. The tool provided a windows user interface enabling the users to control the verification process. The proofs that untrusted program did not leak sensitive information were generated and checked on the host machine and if they are valid, then the untrusted program can be installed and executed safely. Conclusion: By basing proof-carrying code infrastructure on information flow analysis type-system, a sufficient assurance of protecting confidential data manipulated by the mobile program can be obtained. This assurance was come due to the fact that type systems provide a sufficient guarantee of protecting confidentiality.

Non-Interference Control Synthesis for Security Timed Automata

In this paper, the problem of synthesizing controllers that ensures non interference for multilevel security dense timed discrete event systems modeled by an extension of Timed Automata, is addressed for the first time. We first discuss a notion of non interference for dense real-time systems that refines notions existing in the literature and investigate decidability issues raised by the verification problem for dense time properties. We then prove the decidability of the problem of synthesis of the timed controller for some of these timed non interference properties, providing so a symbolic method to synthesize a controller that ensures them.

Process Algebra and Information Flow

Controlling information flows through a system is the fundamental issue in information security. It turns out that making precise the notion of information flow, and in particular the absence of information flow, is a remarkably subtle question. Many formalizations have been proposed, many inspired by the seminal ideas of Goguen and Meseguer with their notion of non-interference. Even now the security community has not reached a consensus on its definition. In this talk we show that casting the problem in a process algebraic framework sheds light on many of the sources of controversy. In particular we argue that non-interference reduces to characterizing the equivalence of processes, itself a rather controversial problem in the process algebra world.