Digital Media and Textuality: From Creation to Archiving

Due to computers' ability to combine different semiotic modes, texts are no longer exclusively comprised of static images and mute words. How have digital media changed the way we write and read? What methods of textual and data analysis have emerged? How do we rescue digital artifacts from obsolescence? And how can digital media be used or taught inside classrooms? These and other questions are addressed in this volume that assembles contributions by artists, writers, scholars and editors. They offer a multiperspectival view on the way digital media have changed our notion of textuality

Digital Media and Textuality

Due to computers' ability to combine different semiotic modes, texts are no longer exclusively comprised of static images and mute words. How have digital media changed the way we write and read? What methods of textual and data analysis have emerged? How do we rescue digital artifacts from obsolescence? And how can digital media be used or taught inside classrooms? These and other questions are addressed in this volume that assembles contributions by artists, writers, scholars and editors such as Dene Grigar, Sandy Baldwin, Carlos Reis, and Frieder Nake. They offer a multiperspectival view on the way digital media have changed our notion of textuality

Digital Media and Textuality

Due to computers' ability to combine different semiotic modes, texts are no longer exclusively comprised of static images and mute words. How have digital media changed the way we write and read? What methods of textual and data analysis have emerged? How do we rescue digital artifacts from obsolescence? And how can digital media be used or taught inside classrooms? These and other questions are addressed in this volume that assembles contributions by artists, writers, scholars and editors such as Dene Grigar, Sandy Baldwin, Carlos Reis, and Frieder Nake. They offer a multiperspectival view on the way digital media have changed our notion of textuality

Compositional Typed Analysis of ARBAC Policies

Model-checking is a popular approach to the security analysis of ARBAC policies, but its effectiveness is hindered by the exponential explosion of the ways in which different users can be assigned to different role combinations. In this paper we propose a paradigm shift, based on the observation that, while verifying ARBAC by exhaustive state search is complex, realistic policies often have rather simple security proofs, and we propose to use types as an effective tool to leverage this simplicity. Concretely, we present a static type system to verify the security of ARBAC policies, along with a sound and complete type inference algorithm used to automate the verification process. We then introduce compositionality results, which identify sufficient conditions to preserve the security guarantees obtained by the verification of different sub-policies when these sub-policies are combined together: this compositional reasoning is crucial when policy administration is highly distributed and naturally supports the security analysis of evolving ARBAC policies. We evaluate our approach by implementing TAPA, a static analyser for ARBAC policies based on our theory, which we test on a number of relatively large, publicly available policies from the literature