Information flow control systems provide the guarantees that are required in today’s security-relevant systems. While the literature has produced a wealth of techniques to ensure a given security policy, there is only a small number of implementations, and even these are mostly restricted to theoretical languages or a subset of an existing language. Previously, we presented the theoretical foun...

Abstract: The real decentralized fixed mode radius measures how “near” a decentralized LTI system is from having a decentralized fixed mode (DFM) present. In this paper, some properties of the real DFM radius are discussed, a procedure for computing the actual system parametric perturbations that achieve the real DFM radius is presented, and the real DFM radius is extended to deal with structur...

Historically, dynamic techniques are the pioneers of the area of information flow in the 70’s. In their seminal work, Denning and Denning suggest a static alternative for information-flow analysis. Following this work, the 90’s see the domination of static techniques for information flow. The common wisdom appears to be that dynamic approaches are not a good match for security since monitoring ...

Most attempts at analysing secure information flow in programs are based on domain-specific logics. Though computationally feasible, these approaches suffer from the need for abstraction and the high cost of building dedicated tools for real programming languages. We recast the information flow problem in a general program logic rather than a problem-specific one. We investigate the feasibility...

The ability to enforce usage policies attached to data in a fine grained manner requires that the system be able to trace and control the flow of information within it. This paper presents the design and implementation of such an information flow control system as a Java Virtual Machine, called Trishul. In particular we describe a novel way to address the hard problem of tracing implicit inform...

Cooperation requires sharing data, but enforcing access restrictions across enterprises is a challenge. Different sites have different policies and use a variety of access control methods that are tailored to the individual enterprises’ needs. Mapping one set of rules into another may require complex computations, possibly with a separate method for each pair of sites. This paper proposes an in...

This document describes use cases and documents call flows that require the History-Info header field to capture the Request-URIs as a Session Initiation Protocol (SIP) Request is retargeted. The use cases are described along with the corresponding call flow diagrams and messaging details.

The modern enterprise depends upon timely and effective flows of knowledge through its organizations for success. But knowledge is not evenly distributed through the enterprise, and a dearth of information systems is available to enable such timely and effective flows. Further, the few theoretical knowledge-flow models available have not yet been developed to a point where they can effectively ...

Given an ensemble of autonomous agents and a task to achieve cooperatively, how much do the agents need to know about the state of the ensemble and about the task in order to achieve it? We introduce new methods to understand these aspects of decentralized control. Precisely, we introduce a framework to capture what agents with partial information can achieve by cooperating and illustrate its u...

The ability to enforce usage policies attached to data in a fine grained manner requires that the system be able to trace and control the flow of information within it. This paper presents the design and implementation of such an information flow control system, named Trishul, as a Java Virtual Machine. In particular we address the hard problem of tracing implicit information flow, which had no...