| 1. |
- Meech, K. J., et al.
(författare)
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EPOXI: Comet 103P/Hartley 2 Observations from a Worldwide Campaign
- 2011
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Ingår i: Astrophysical Journal Letters. - London : IOP. - 2041-8213 .- 2041-8205. ; 734:L1, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- Earth- and space-based observations provide synergistic information for space mission encounters by providing data over longer timescales, at different wavelengths and using techniques that are impossible with an in situ flyby. We report here such observations in support of the EPOXI spacecraft flyby of comet 103P/Hartley 2. The nucleus is small and dark, and exhibited a very rapidly changing rotation period. Prior to the onset of activity, the period was ~16.4?hr. Starting in 2010 August the period changed from 16.6?hr to near 19?hr in December. With respect to dust composition, most volatiles and carbon and nitrogen isotope ratios, the comet is similar to other Jupiter-family comets. What is unusual is the dominance of CO 2 -driven activity near perihelion, which likely persists out to aphelion. Near perihelion the comet nucleus was surrounded by a large halo of water-ice grains that contributed significantly to the total water production.
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| 2. |
- Stefan, D., et al.
(författare)
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Flexible Dynamic Information Flow Control in Haskell
- 2011
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Ingår i: SIGPLAN Notices (ACM Special Interest Group on Programming Languages). - : Association for Computing Machinery (ACM). - 0730-8566 .- 0362-1340 .- 1558-1160. ; 46:12, s. 95-106
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Tidskriftsartikel (refereegranskat)abstract
- We describe a new, dynamic, floating-label approach to language-based information flow control, and present an implementation in Haskell. A labeled IO monad, LIO, keeps track of a current label and permits restricted access to IO functionality, while ensuring that the current label exceeds the labels of all data observed and restricts what can be modified. Unlike other language-based work, LIO also bounds the current label with a current clearance that provides a form of discretionary access control. In addition, programs may encapsulate and pass around the results of computations with different labels. We give precise semantics and prove confidentiality and integrity properties of the system.
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| 3. |
- Stefan, D., et al.
(författare)
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Addressing covert termination and timing channels in concurrent information flow systems
- 2012
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Ingår i: ACM SIGPLAN Notices. - : Association for Computing Machinery (ACM). - 1523-2867 .- 0362-1340 .- 1558-1160. ; 47:9, s. 201-213
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Tidskriftsartikel (refereegranskat)abstract
- When termination of a program is observable by an adversary, confidential information may be leaked by terminating accordingly. While this termination covert channel has limited bandwidth for sequential programs, it is a more dangerous source of information leakage in concurrent settings. We address concurrent termination and timing channels by presenting a dynamic information-flow control system that mitigates and eliminates these channels while allowing termination and timing to depend on secret values. Intuitively, we leverage concurrency by placing such potentially sensitive actions in separate threads. While termination and timing of these threads may expose secret values, our system requires any thread observing these properties to raise its information-flow label accordingly, preventing leaks to lower-labeled contexts. We implement this approach in a Haskell library and demonstrate its applicability by building a web server that uses information-flow control to restrict untrusted web applications.
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| 4. |
- Stefan, D., et al.
(författare)
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Building secure systems with LIO (demo)
- 2014
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Ingår i: ACM SIGPLAN Notices. - New York, NY, USA : ACM. - 1523-2867. ; 49:12, s. 93-94
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Tidskriftsartikel (refereegranskat)abstract
- LIO is a decentralized information flow control (DIFC) system, implemented in Haskell. In this demo proposal, we give an overview of the LIO library and show how LIO can be used to build secure systems. In particular, we show how to specify high-level security policies in the context of web applications, and describe how LIO automatically enforces these policies even in the presence of untrusted code.
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