Srijith Krishnan Nair

A Virtual Machine Based Information Flow Control System for Policy Enforcement

The ability to enforce usage policies attached to data in a fine grained manner requires that the system be able to trace and control the flow of information within it. This paper presents the design and implementation of such an information flow control system, named Trishul, as a Java Virtual Machine. In particular we address the problem of tracing implicit information flow, which had not been resolved by previous run-time systems and the additional intricacies added on by the Java architecture. We argue that the security benefits offered by Trishul are substantial enough to counter-weigh the performance overhead of the system as shown by our experiments.

Enabling DRM-preserving digital content redistribution

Traditionally, the process of online digital content distribution has involved a limited number of centralised distributors selling protected contents and licenses authorising the use of these contents, to consumers. In this paper, we extend this model by introducing a security scheme that enables DRM preserving digital content redistribution. Essentially consumers can not only buy the rights to use digital content but also the rights to redistribute it to other consumers in a DRM controlled fashion. We examine the threats associated with such a redistribution model and explain how our scheme addresses them.

A Hybrid PKI-IBC Based Ephemerizer System

The concept of an Ephemerizer system has been introduced in earlier works as a mechanism to ensure that a file deleted from the persistent storage remains unrecoverable. The principle involved storing the data in an encrypted form in the user’s machine and the key to decrypt the data in a physically separate machine. However the schemes proposed so far do not provide support for fine-grained user settings on the lifetime of the data nor support any mechanism to check the integrity of the system that is using the secret data. In addition we report the presence of a vulnerability in one version of the proposed scheme that can be exploited by an attacker to nullify the ephemeral nature of the keys. We propose and discuss in detail an alternate Identity Based cryptosystem powered scheme that overcomes the identified limitations of the original system.

Enforcing DRM policies across applications

In this paper we present Trishul-UCON (T-UCON), a DRM system based on the UCON_ABC model. T-UCON is designed to be capable of enforcing not only application-specific policies, as any existing software-based DRM solution does, but also DRM policies across applications. This is achieved by binding the DRM policy only to the content it protects with no relations to the application(s) which will use this content. Furthermore, to guarantee that the policy is continuously enforced, we designed T-UCON as a JVM-based middleware that mediates the usage requests of any Java application to the protected content. Each request is granted or denied according to the content policy. We illustrate the unique features of T-UCON by using typical examples of DRM policies such as the pay-per-use and the use only N times scenarios. Preliminary results on the overhead of our solution are also provided.

Virtualised Trusted Computing Platform for Adaptive Security Enforcement of Web Services Interactions

Security enforcement framework is an important aspect of any distributed system. With new requirements imposed by SOA-based business models, adaptive security enforcement on the application level becomes even more important. Our work on the enforcement framework to date has resulted in a comprehensive middleware-based solution leveraging on Web services technologies. However, potential merits of hardware-based solutions to further secure application exposure have not been considered so far. This paper describes a method for combining software resource level security features offered by Web services technologies, with the hardware-based security mechanisms offered by trusted computing platform and system virtualisation approaches. In particular, we propose trust-based architecture for protecting the enforcement middleware deployed at the policy enforcement endpoints of Web and grid services. The main motivation is to additionally secure execution environment of the applications, by providing virtual machine level separation that maps from logical domains imposed by Web services level enforcement policies.

Secure web service federation management using tpm virtualisation

Web Services and SOA provide interoperability and architectural baseline for flexible and dynamic cross enterprise collaborations, where execution and use of the participating services contributes to the common objective. Relationships within these collaborations are complex, with services joining and leaving throughout the life cycle, or the same services being offered in several collaborations simultaneously. This provides strong requirements for federated security, where integrity and confidentiality of the collaboration must be maintained through membership control, security policy enforcement and separation of web service instance interactions in different collaborations. In this paper we propose a new Web Services (WS) framework for managing and controlling WS interactions in a federated environment, leveraging on platform virtualisation architecture and the functionalities provided by trusted secure hardware. The framework allows configuring policies that define collaboration membership, and enforce access to the collaboration per-WS instance. In addition, since the access to the configurations is restricted, it provides masterslave model where only authorised administrative entity can modify any of the above - either at the deployment or at the execution time. Some of the benefits of the proposed approach are: fine-grained external exposure of WSs, a flexible model for group membership control and revocation and hardware-enabled secure virtualised system providing functional process isolation and strong data security.

Floodgate: A Micropayment Incentivized P2P Content Delivery Network

As the sale of digital content is moving more and more online, the content providers are beginning to realize that bandwidth infrastructures are not easily scalable. The emergence of peer-to-peer content delivery networks present these providers with a way to overcome this limitation. However, such networks have so far been ad-hoc in nature. One of the main reason for this has been the lack of incentives for end users to contribute their bandwidth to the network. In this paper we present the design and implementation of a peer-to-peer protocol named Floodgate that provides a micropayment based incentive for peers to contribute their bandwidth. Floodgate implements an optimistic fair exchange protocol and is designed to be resilient against targeted attacks. Performance measurements, including those conducted over the PlanetLab infrastructure, show that Floodgates security and cryptographic overheads are low when compared against the standard BitTorrent implementation.