Stefano Calzavara

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Browser-based defenses have recently been advocated as an effective mechanism to protect web applications against the threats of session hijacking, fixation, and related attacks. In existing approaches, all such defenses ultimately rely on client-side heuristics to automatically detect cookies containing session information, to then protect them against(More)
—Enforcing protection at the browser side has recently become a popular approach for securing web authentication. Though interesting, existing attempts in the literature only address specific classes of attacks, and thus fall short of providing robust foundations to reason on web authentication security. In this paper we provide such foundations, by(More)
Session cookies constitute one of the main attack targets against client authentication on the Web. To counter that, modern web browsers implement native cookie protection mechanisms based on the Secure and HttpOnly flags. While there is a general understanding about the effectiveness of these defenses, no formal result has so far been proved about the(More)
—Type systems for authorization are a popular device for the specification and verification of security properties in cryptographic applications. Though promising , existing frameworks exhibit limited expressive power, as the underlying specification languages fail to account for powerful notions of authorization based on access counts, usage bounds, and(More)
Recent research has shown that it is possible to leverage general-purpose theorem proving techniques to develop powerful type systems for the verification of a wide range of security properties on application code. Although successful in many respects, these type systems fall short of capturing resource-conscious properties that are crucial in large classes(More)
The widespread adoption of Android devices has attracted the attention of a growing computer security audience. Fundamental weaknesses and subtle design flaws of the Android architecture have been identified, studied and fixed, mostly through techniques from data-flow analysis, runtime protection mechanisms, or changes to the operating system. This paper(More)
—Role-based Access Control (RBAC) is one of the most widespread security mechanisms in use today. Given the growing complexity of policy languages and access control systems, verifying that such systems enforce the desired invariants is recognized as a security problem of crucial importance. In the present paper, we develop a framework for the formal(More)
Browser-based defenses have recently been advocated as an effective mechanism to protect potentially insecure web applications against the threats of session hijacking, fixation, and related attacks. In existing approaches, all such defenses ultimately rely on client-side heuristics to automatically detect cookies containing session information, to then(More)
Sessions on the web are fragile. They have been attacked successfully in many ways, by network-level attacks, by direct attacks on session cookies (the main mechanism for implementing the session concept) and by application-level attacks where the integrity of sessions is violated by means of cross-site request forgery or malicious script inclusion. This(More)
Recent research has shown that it is possible to leverage general-purpose theorem-proving techniques to develop powerful type systems for the verification of a wide range of security properties on application code. Although successful in many respects, these type systems fall short of capturing resource-conscious properties that are crucial in large classes(More)