Paolo Falcarin

A family of experiments to assess the effectiveness and efficiency of source code obfuscation techniques

Context: code obfuscation is intended to obstruct code understanding and, eventually, to delay malicious code changes and ultimately render it uneconomical. Although code understanding cannot be completely impeded, code obfuscation makes it more laborious and troublesome, so as to discourage or retard code tampering. Despite the extensive adoption of obfuscation, its assessment has been addressed indirectly either by using internal metrics or taking the point of view of code analysis, e.g., considering the associated computational complexity. To the best of our knowledge, there is no publicly available user study that measures the cost of understanding obfuscated code from the point of view of a human attacker. Aim: this paper experimentally assesses the impact of code obfuscation on the capability of human subjects to understand and change source code. In particular, it considers code protected with two well-known code obfuscation techniques, i.e., identifier renaming and opaque predicates. Method: We have conducted a family of five controlled experiments, involving undergraduate and graduate students from four Universities. During the experiments, subjects had to perform comprehension or attack tasks on decompiled clients of two Java network-based applications, either obfuscated using one of the two techniques, or not. To assess and compare the obfuscation techniques, we measured the correctness and the efficiency of the performed task. Results: —at least for the tasks we considered—simpler techniques (i.e., identifier renaming) prove to be more effective than more complex ones (i.e., opaque predicates) in impeding subjects to complete attack tasks.

Guest Editors' Introduction: Software Protection

A computer systems security can be compromised in many ways a denial-of-service attack can make a server inoperable, a worm can destroy a users private data, or an eavesdrop per can reap financial rewards by inserting himself in the communication link between a customer and her bank through a man-in-the-middle (MITM) attack. What all these scenarios have in common is that the adversary is an untrusted entity that attacks a system from the outside-we assume that the computers under attack are operated by benign and trusted users. But if we remove this assumption, if we allow anyone operating a computer system- from system administrators down to ordinary users-to compromise that systems security, we find ourselves in a scenario that has received comparatively little attention. Methods for protecting against MATE attacks are variously known as anti-tamper techniques, digital asset protection, or, more commonly, software protection.

Dynamic context-aware business process: a rule-based approach supported by pattern identification

Making a business process more dynamic is an open issue, and we think it is feasible if we decompose the business process structure in a set of rules, like ECA (Event Condition Action) rules, each of them representing a transition of the business process, i.e. an edge of the business process graph structure. As a consequence the business process engine can be realized by reusing and integrating an existing Rule Engine. We are proposing a way for representing Dynamic Business Process in terms of Rules based on patterns identification. With this approach it is easy to apply on a business process instance both user-based personalization rules and automatic rules inferred by an underlying context-aware system.

Communication Web Services Composition and Integration

Nowadays, the development of services that span over both the Internet and telephony networks is driving significant efforts towards the integration of services offered by IT providers with telecom operators ones. Web services have often been recommended for providing, composing and realizing telecom services but introducing them means facing up with several challenges. This work sharpens benefits and drawbacks of Web service applications within a telecom environment focusing in particular on JAIN SLEE architecture, which defines a standard environment targeted at communication-based applications

Synthesizing service composition models on the basis of temporal business rules

Transformational approaches to generating design and implementation models from requirements can bring effectiveness and quality to software development. In this paper we present a framework and associated techniques to generate the process model of a service composition from a set of temporal business rules. Dedicated techniques including path-finding, branching structure identification and parallel structure identification are used for semi-automatically synthesizing the process model from the semantics-equivalent Finite State Automata of the rules. These process models naturally satisfy the prescribed behavioral constraints of the rules. With the domain knowledge encoded in the temporal business rules, an executable service composition program, e.g., a BPEL program, can be further generated from the process models. A running example in the e-business domain is used for illustrating our approach throughout this paper.

Towards experimental evaluation of code obfuscation techniques

While many obfuscation schemes proposed, none of them satisfy any strong definition of obfuscation. Furthermore secure general-purpose obfuscation algorithms have been proven to be impossible. Nevertheless, obfuscation schemes which in practice slow down malicious reverse-engineering by obstructing code comprehension for even short periods of time are considered a useful protection against malicious reverse engineering. In previous works, the difficulty of reverse engineering has been mainly estimated by means of code metrics, by the computational complexity of static analysis or by comparing the output of de-obfuscating tools. In this paper we take a different approach and assess the difficulty attackers have in understanding and modifying obfuscated code through controlled experiments involving human subjects.

Towards an Efficient Context-Aware System: Problems and Suggestions to Reduce Energy Consumption in Mobile Devices

Looking for optimizing the battery consumption is an open issue, and we think it is feasible if we analyze the battery consumption behavior of a typical context-aware application to reduce context-aware operations at runtime. This analysis is based on different context sensors configurations. Actually existing context-aware approaches are mainly based on collecting and sending context data to external components, without taking into account how expensive are these operations in terms of energy consumption. As a first result of our work in progress, we are proposing a way for reducing the context data publishing. We have designed a testing battery consumption architecture supported by Nokia Energy Profiler tool to verify consumption in different scenarios.

Application-Oriented Trust in Distributed Computing

Preserving integrity of applications being executed in remote machines is an open problem. Integrity requires that application code is not tampered with, prior to or during execution, by a rogue user or a malicious software agent. This paper presents a methodology to enforce runtime integrity of application code by means of an integrity- preserving software component that is combined with the application. The software component is a trusted logic that can be replaced continuously from a remote location during run-time. For added assurance, the software component produces continuous sequence of proofs of its proper operation that are verified remotely.

Communication Web Services and JAIN-SLEE Integration Challenges

Meshing up telecommunication and IT resources seems to be the real challenge for supporting the evolution towards the next generation of Web Services. In telecom world, JAIN-SLEE (JAIN Service Logic Execution Environment) is an emerging standard specification for Java service platforms targeted to host value added services, composed of telecom and IT services.In this paper we describe StarSLEE platform which extends JAIN-SLEE in order to compose JAIN-SLEE services with Web services and the StarSCE service creation environment which allows exporting value added services as communication web services, and we analyze open issues that must be addressed to introduce Web Services in new telecom service platforms.

Realizing an MDA and SOA Marriage for the Development of Mobile Services

The paper presents an approach for developing composite tele-communication services running on mobile phones which takes advantage of the use of model driven techniques as well as the loose coupling paradigm in SOA. A domain-specific UML dialect named SPATEL has been developed which serves as the basis for generating applications that can be deployed in distinct terminals and servers technologies. The composite services typically combines telecommunication enablers - like SMS sending and GSM locali-sation - with traditional IT components accessible over the internet, such as a Yellow Page facility. This work has been conducted in the context of the IST SPICE European collaborative project.