15,123 research outputs found
Plugging Side-Channel Leaks with Timing Information Flow Control
The cloud model's dependence on massive parallelism and resource sharing
exacerbates the security challenge of timing side-channels. Timing Information
Flow Control (TIFC) is a novel adaptation of IFC techniques that may offer a
way to reason about, and ultimately control, the flow of sensitive information
through systems via timing channels. With TIFC, objects such as files,
messages, and processes carry not just content labels describing the ownership
of the object's "bits," but also timing labels describing information contained
in timing events affecting the object, such as process creation/termination or
message reception. With two system design tools-deterministic execution and
pacing queues-TIFC enables the construction of "timing-hardened" cloud
infrastructure that permits statistical multiplexing, while aggregating and
rate-limiting timing information leakage between hosted computations.Comment: 5 pages, 3 figure
Using formal metamodels to check consistency of functional views in information systems specification
UML notations require adaptation for applications such as Information Systems (IS). Thus we have defined IS-UML. The purpose of this article is twofold. First, we propose an extension to this language to deal with functional aspects of IS. We use two views to specify IS transactions: the first one is defined as a combination of behavioural UML diagrams (collaboration and state diagrams), and the second one is based on the definition of specific classes of an extended class diagram. The final objective of the article is to consider consistency issues between the various diagrams of an IS-UML specification. In common with other UML languages, we use a metamodel to define IS-UML. We use class diagrams to summarize the metamodel structure and a formal language, B, for the full metamodel. This allows us to formally express consistency checks and mapping rules between specific metamodel concepts. (C) 2007 Elsevier B.V. All rights reserved
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