Biblio

In many client-facing applications, a vulnerability in any part can compromise the entire application. This paper describes the design and implementation of Passe, a system that protects a data store from unintended data leaks and unauthorized writes even in the face of application compromise. Passe automatically splits (previously shared-memory-space) applications into sandboxed processes. Passe limits communication between those components and the types of accesses each component can make to shared storage, such as a backend database. In order to limit components to their least privilege, Passe uses dynamic analysis on developer-supplied end-to-end test cases to learn data and control-flow relationships between database queries and previous query results, and it then strongly enforces those relationships. Our prototype of Passe acts as a drop-in replacement for the Django web framework. By running eleven unmodified, off-the-shelf applications in Passe, we demonstrate its ability to provide strong security guarantees-Passe correctly enforced 96% of the applications' policies-with little additional overhead. Additionally, in the web-specific setting of the prototype, we also mitigate the cross-component effects of cross-site scripting (XSS) attacks by combining browser HTML5 sandboxing techniques with our automatic component separation.

Security companies have recently realised that mining massive amounts of security data can help generate actionable intelligence and improve their understanding of Internet attacks. In particular, attack attribution and situational understanding are considered critical aspects to effectively deal with emerging, increasingly sophisticated Internet attacks. This requires highly scalable analysis tools to help analysts classify, correlate and prioritise security events, depending on their likely impact and threat level. However, this security data mining process typically involves a considerable amount of features interacting in a non-obvious way, which makes it inherently complex. To deal with this challenge, we introduce MR-TRIAGE, a set of distributed algorithms built on MapReduce that can perform scalable multi-criteria data clustering on large security data sets and identify complex relationships hidden in massive datasets. The MR-TRIAGE workflow is made of a scalable data summarisation, followed by scalable graph clustering algorithms in which we integrate multi-criteria evaluation techniques. Theoretical computational complexity of the proposed parallel algorithms are discussed and analysed. The experimental results demonstrate that the algorithms can scale well and efficiently process large security datasets on commodity hardware. Our approach can effectively cluster any type of security events (e.g., spam emails, spear-phishing attacks, etc) that are sharing at least some commonalities among a number of predefined features.
 

Threat evaluation is concerned with estimating the intent, capability and opportunity of detected objects in relation to our own assets in an area of interest. To infer whether a target is threatening and to which degree is far from a trivial task. Expert operators have normally to their aid different support systems that analyze the incoming data and provide recommendations for actions. Since the ultimate responsibility lies in the operators, it is crucial that they trust and know how to configure and use these systems, as well as have a good understanding of their inner workings, strengths and limitations. To limit the negative effects of inadequate cooperation between the operators and their support systems, this paper presents a design proposal that aims at making the threat evaluation process more transparent. We focus on the initialization, configuration and preparation phases of the threat evaluation process, supporting the user in the analysis of the behavior of the system considering the relevant parameters involved in the threat estimations. For doing so, we follow a known design process model and we implement our suggestions in a proof-of-concept prototype that we evaluate with military expert system designers.

Cryptographically-Curated File System (CCFS) proposed in this work supports the adoption of Information-Centric Networking. CCFS utilizes content names that span trust boundaries, verify integrity, tolerate disruption, authenticate content, and provide non-repudiation. Irrespective of the ability to reach an authoritative host, CCFS provides secure access by binding a chain of trust into the content name itself. Curators cryptographically bind content to a name, which is a path through a series of objects that map human meaningful names to cryptographically strong content identifiers. CCFS serves as a network layer for storage systems unifying currently disparate storage technologies. The power of CCFS derives from file hashes and public keys used as a name with which to retrieve content and as a method of verifying that content. We present results from our prototype implementation. Our results show that the overhead associated with CCFS is not negligible, but also is not prohibitive.