EmLog:Tamper-Resistant System Logging for Constrained Devices with TEEs

Remote mobile and embedded devices are used to deliver increasingly impactful services, such as medical rehabilitation and assistive technologies. Secure system logging is beneficial in these scenarios to aid audit and forensic investigations particularly if devices bring harm to end-users. Logs should be tamper-resistant in storage, during execution, and when retrieved by a trusted remote verifier. In recent years, Trusted Execution Environments (TEEs) have emerged as the go-to root of trust on constrained devices for isolated execution of sensitive applications. Existing TEE-based logging systems, however, focus largely on protecting server-side logs and offer little protection to constrained source devices. In this paper, we introduce EmLog -- a tamper-resistant logging system for constrained devices using the GlobalPlatform TEE. EmLog provides protection against complex software adversaries and offers several additional security properties over past schemes. The system is evaluated across three log datasets using an off-the-shelf ARM development board running an open-source, GlobalPlatform-compliant TEE. On average, EmLog runs with low run-time memory overhead (1MB heap and stack), 430--625 logs/second throughput, and five-times persistent storage overhead versus unprotected logs.Comment: Accepted at the 11th IFIP International Conference on Information Security Theory and Practice (WISTP '17

Spidle: A DSL approach to specifying streaming application

International audienceMultimedia stream processing is a rapidly evolving domain which requires much software development and expects high performance. Developing a streaming application often involves low-level programming, critical memory management, and finely tuned scheduling of processing steps. To address these problems, we present a domain-specific language (DSL) named Spidle, for specifying streaming applications. Spidle offers high-level and declarative constructs; compared to general-purpose languages (GPL), it improves robustness by enabling a variety of verifications to be performed. To assess the expressiveness of Spidle in practice, we have used it to specify a number of standardized and special-purpose streaming applications. These specifications are up to \spidlesmaller times smaller than equivalent programs written in a GPL such as C. We have implemented a compiler for Spidle. Preliminary results show that compiled Spidle programs are roughly as efficient as the compiled, equivalent C programs

Influence of recycled basalt-aramid fibres integration on the mechanical and thermal properties of brake friction composites

In the brake friction composites(BFCs), fibres take part in significant attention as reinforcement in governing mechanical and thermal-mechanical properties. The current investigation aims to develop hybrid brake friction composites using recycled basalt- aramid fibre integration and to characterise for its mechanical and thermal properties. The experiments related to thermal (heat swell, loss of ignition and thermal conductivity) and mechanical (tensile, compression, flexural and impact) properties were conducted as per industrial standards. From the experimental investigations, it was concluded that fibre inclusion in the BFCs enhanced the mechanical and thermal properties considerably. Further, with the aid of scanning electron microscope (SEM), fracture interfaces of the tested friction composites were analyzed for various characteristics like pullout, void, fibre-matrix bonding etc

Characterization of raw and alkali treated new natural cellulosic fibers from Tridax procumbens

The aim of this study is to investigate natural cellulosic fibers extracted from Tridax procumbens plants. The obtained fibers were alkali treated for their effective usage as reinforcement in composites. The physical, chemical, crystallinity, thermal, wettability and surface characteristics were analyzed for raw, and alkali treated Tridax procumbens fibers (TPFs). The test results conclude that there was an increase in cellulose content with a reduction in hemicellulose, lignin, and wax upon alkali treatment. This enhanced the thermal stability, tensile strength, crystallinity, and surface roughness characteristics. The contact angle was also lesser for treated TPFs which prove its better wettability with the liquid phase. The Weibull distribution analysis was adopted for the analysis of the fiber diameter and tensile properties. Thus the considerable improvement in the properties of alkali treated TPFs would be worth for developing high-performance polymer composites

End-to-End Security of Information Flow in Web-based Applications

Web-based applications and services are increasingly being used in security-sensitive tasks. Current security protocols rely on two crucial assumptions to protect the confidentiality and integrity of information: First, they assume that end-point software used to handle security-sensitive information is free from vulnerabilities. Secondly, these protocols assume point-to-point communication between a client and a service provider. However, these assumptions do not hold true with large and complex vulnerable end point software such as the Internet browser or web services middleware or in web service compositions where there can be multiple value-adding service providers interposed between a client and the original service provider. To address the problem of large and complex end-point software, we present the AppCore approach which uses manual analysis of information flow, as opposed to purely automated approaches, to split existing software into two parts: a simplified trusted part that handles security-sensitive information and a legacy, untrusted part that handles non-sensitive information without access to sensitive information. Not only does this approach avoid many common and well-known vulnerabilities in the legacy software that compromised sensitive information, it also greatly reduces the size and complexity of the trusted code, thereby making exhaustive testing or formal analysis more feasible. We demonstrate the feasibility of the AppCore approach by constructing AppCores for two real-world applications: a client-side AppCore for https-based applications and an AppCore for web service platforms. Our evaluation shows that security improvements and complexity reductions (over a factor of five) can be attained with minimal modifications to existing software (a few tens of lines of code, and proxy settings of a browser) and an acceptable performance overhead (a few percent). To protect the communication of sensitive information between the clients and service providers in web service compositions, we present an end-to-end security framework called WS-FESec that provides end-to-end security properties even in the presence of misbehaving intermediate services. We show that WS-FESec is flexible enough to support the lattice model of secure information flow and it guarantees precise security properties for each component service at a modest cost of a few milliseconds per signature or encrypted field.Ph.D

A comparative study of mechanical, dynamic mechanical and morphological characterization of tampico and coir fibre-reinforced LLDPE processed by rotational moulding

Natural fibres find their application as a reinforcing agent for polymer composites to obtain parts with improved mechanical properties. Manufacturing of non-metallic products is incorporated with natural fibres for better strength and to reduce cost. Rotational moulding is a process used for the manufacturing of hollow plastic products, especially water tanks, plastic fuel tanks, barrels, kayaks, refrigerated panels, etc. Incorporation of natural fibres to reinforce polymers in rotational moulding process is a tedious task; since there is no control over fibre and polymer powder mixture, which is rotating bi-axially, it may lead to fibre agglomeration. The present work investigates the mouldability of linear low density polyethylene composites with tampico and coir fibre as the reinforcement agents using a bi-axial rotomoulding machine. NaOH-treated fibres with 5, 10 and 15% by weight have been added to the linear low density polyethylene matrix, and the composites were prepared by rotational moulding process. Mechanical properties such as tensile strength, flexural strength, impact strength and hardness have been investigated. Dynamic mechanical behaviour such as storage modulus, loss modulus and tan  δ of the different composites has been investigated with dynamic mechanical analyser. Fractured surfaces were examined qualitatively with the help of a scanning electron microscope for determining the interfacial properties and fibre adhesion between the fibres and the linear low density polyethylene matrix. </jats:p