J. Allen. A comparison of non-interference and nondeducibility using CSP. In Proceedings of the 1991.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....or independence) in a multi level security system: that is the question of whether a high level user, High, can pass information to a low level user, Low, via a covert channel. A common approach has been to produce a definition of information flow in a process algebraic setting; see, for example [1, 14, 4, 12, 7, 5]. Most definitions are based around asking whether Low can distinguish between two di#erent behaviours of High, so that High can use the system to pass at least one bit of information to Low. However, in many circumstances, some flow of information will be inevitable and acceptable, providing it ....

P. G. Allen. A comparison of non-interference and non-deducibility using CSP. In Proceedings of the 4th IEEE Computer Security Foundations Workshop, 1991.

....ability to analyse determinism. An excellent survey can be found in Graham Cumming s thesis [5] Some of the proposed conditions have been essentially the same as LtrINV , others have been equivalent to EtrINV , and others di#erent to both. The definitions of non interference given by Allen [1], Graham Cumming [5] and Ryan [17] are all essentially equivalent to LtrINV , the latter also encompassing LfdINV . Graham Cumming demonstrates that these three are essentially equivalent, and it is not at all hard to show that Allen s definition (here altered to reflect our notation and ....

P.G. Allen, A comparison of non-interference and non-deducibility using CSP, In Proceedings of the

....Related Work The use of process algebras to formalize information flow security properties is not new. In [57] it is possible to find a definition of Non Interference given on CSP [39] It looks like SNNI with some side conditions on acceptable low level actions. This definition is recalled in [4], where a comparison with another information flow property is reported. More recent results based on the CSP model are contained in [56] where the authors introduce some information flow security properties based on the notion of deterministic views and show how to automatically verify them ....

P. G. Allen. "A Comparison of Non-Interference and Non-Deducibility using CSP". In Proceedings of the Fourth IEEE Computer Security Foundations Workshop, pages 43--54, Franconia, New Hampshire, June 1991.

....in other words, we give a formal definition of the capacity of covert channels. Our definition uses the process algebra CSP, and is based upon counting the number of di#erent behaviours of a high level user that can be distinguished by a low level user. 1 Introduction Previous work, for example [1, 12, 4, 10, 6, 5], has sought to capture the notion of information flow (sometimes called non interference or independence) in a multi level security system, that is the question of whether a high level user, High, can pass information to a low level user, Low, via a covert channel. Most definitions are based ....

P. G. Allen. A comparison of non-interference and non-deducibility using CSP. In Proceedings of the 4th IEEE Computer Security Foundations Workshop, 1991.

....obtained from fl deleting all the high level actions (inputs and outputs) is still a trace. The need for an explicit protection of high level outputs was argued in [13] The particular property we are going to propose, called Strong NNI (SNNI for short) is similar to a number of generalizations [29, 1, 12] of NI over the CSP [15] process algebra. 5 Definition 3.3 (SNNI: Strong NNI ) E 2 SNNI ( 8fl 2 T (E) low(fl) 2 T (E) The SPA version of SNNI is as follows: Proposition 3.4 E 2 SNNI ( E=ActH T E n ActH . Proof. It is sufficient to show that if E is SNNI then T (E=ActH ) T (E n Act ....

....two papers dealing with security properties in a process algebraic setting. One is [12] where Non Interference is investigated in CSP [15] there, the author proposes a set of algebraic laws which, essentially, characterize the compositionality on NI w.r.t. the CSP combinators. The other one is [1], where Non Interference and Non Deducibility are compared. A strong criticism against the possibilistic approach to information flow security we have investigated here is reported in [16] where the author claims that the properties in this class can only offer necessary conditions to security. ....

P. G. Allen. "A Comparison of Non-Interference and Non-Deducibility using CSP". In Proceedings of the Fourth Workshop on the Foundations of Computer Security, pages 43--54, Franconia, New Hampshire, June 1991.

..... 9 Related Work The use of process algebras to formalize information flow security properties is not new. In [26] it is possible to find a definition of Non Interference given on CSP. It looks like SNNI with some side conditions on acceptable low level actions. This definition is recalled in [1], where a comparison with another information flow property is reported. BNDC SBSNNI Nondiv Lowdet L Sec Figure 11: Relations between L Sec, SBSNNI and BNDC More recent results based on CSP model are contained in [25] where the authors introduce some information flow security properties based ....

P. G. Allen. "A Comparison of Non-Interference and Non-Deducibility using CSP". In Proceedings of the Fourth IEEE Computer Security Foundations Workshop, pages 43--54, Franconia, New Hampshire, June 1991.

.... )g: Hence Ryan s definition of security can be formalized as: INVL (P ) b = 8 tr; tr 0 2 traces(P ) q tr j L = tr 0 j L ) inits after L (P; tr) inits after L (P; tr 0 ) refs after L (P; tr) refs after L (P; tr 0 ) Similar definitions have been put forward by Allen [All91], GrahamCumming [GC92] and Jacob [Jac90b] For example, consider the process P 1 b = h l STOP: This is correctly identified as insecure, for consider the traces tr b = hi and tr 0 b = hhi; then tr j L = hi = tr 0 j L, but inits after L (P 1 ; tr) fg 6= inits after L (P 1 ; tr ....

P. G. Allen. A comparison of non-interference and non-deducibility using CSP. In Proceedings of the 4th IEEE Computer Security Foundations Workshop, 1991.

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J. Allen. A comparison of non-interference and nondeducibility using CSP. In Proceedings of the 1991.

No context found.

P.G. Allen. "A Comparison of Non-Interference and NonDeducibility using CSP," Proceedings of the Computer Security Foundations Workshop IV, pages 43-54. IEEE Press. June 1991.

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