Trusted declassification: High-level policy for a security-typed language

Boniface Hicks, Dave King, Patrick McDaniel, Michael Hicks

Research output: Chapter in Book/Report/Conference proceedingConference contribution

26 Scopus citations

Abstract

Security-typed languages promise to be a powerful tool with which provably secure software applications may be developed. Programs written in these languages enforce a strong, global policy of noninterference which ensures that high-security data will not be observable on low-security channels. Because noninterference is typically too strong a property, most programs use some form of declassification to selectively leak high security information, e.g. when performing a password check or data encryption. Unfortunately, such a declassification is often expressed as an operation within a given program, rather than as part of a global policy, making reasoning about the security implications of a policy more difficult. In this paper, we propose a simple idea we call trusted declassification in which special declassifier functions are specified as part of the global policy. In particular, individual principals declaratively specify which declassifies they trust so that all information flows implied by the policy can be reasoned about in absence of a particular program. We formalize our approach for a Java-like language and prove a modified form of noninterference which we call noninterference modulo trusted methods. We have implemented our approach as an extension to Jif and provide some of our experience using it to build a secure e-mail client.

Original languageEnglish (US)
Title of host publicationPLAS 2006 - Proceedings of the 2006 Programming Languages and Analysis for Security Workshop
Pages65-74
Number of pages10
StatePublished - Jul 20 2006
EventPLAS 2006 - 2006 Programming Languages and Analysis for Security Workshop - Ottawa, ON, Canada
Duration: Jun 10 2006Jun 10 2006

Publication series

NamePLAS 2006 - Proceedings of the 2006 Programming Languages and Analysis for Security Workshop
Volume2006

Other

OtherPLAS 2006 - 2006 Programming Languages and Analysis for Security Workshop
CountryCanada
CityOttawa, ON
Period6/10/066/10/06

All Science Journal Classification (ASJC) codes

  • Engineering(all)

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