Franco Frattolillo

Watermarking Protocol for Web Context

Digital watermarking is considered to be a main technology for the copyright protection of multimedia digital content distributed on the Internet. However, watermarking procedures can effectively support copyright protection processes only if they are applied by employing specific watermarking protocols, which define the scheme of the interactions that have to take place among the entities involved in the content protection and web-based distribution. To this end, a number of current watermarking protocols can attain important achievements, such as the correct authentication of buyers without exposing their identities during web transactions and the capability of resorting to trusted watermark certification authorities to ensure a copyright protection process that is able to correctly take into account the rights of both buyers and sellers. However, these protocols are often not suitable for web context, where buyers are usually neither provided with digital certificates issued by trusted certification authorities nor able to autonomously perform complex security actions to purchase digital content distributed by web-based content providers. This paper presents an improved version of a web-oriented and interactive anonymous buyer-seller watermarking protocol previously presented by the author. The protocol overcomes the drawbacks affecting relevant protocols existing in literature, and is based on a design approach that makes it suitable for web contexts.

Running Large-Scale Applications on Cluster Grids

Grid computing enables the enormous, but often poorly utilized, computing resources existing on the Internet to be harnessed in order to solve large-scale problems. However, if they want to solve the problems of configuration and performance optimization of their large-scale applications, programmers wishing to exploit such computing resources have to deal with highly variable communication delays, security threats, machine and network failures, and the distributed ownership of the computing resources. On the other hand, Parallel Virtual Machine (PVM) is still widely used to develop high performance parallel applications on high performance/cost ratio computing platforms, such as workstation clusters. However, workstations belonging to networked clusters cannot often be exploited since they are provided with private IP addresses, being hidden from the Internet by publicly addressable IP front-end machines. This paper presents an extension of PVM that enables such clustered machines hidden from the Internet to take part in a PVM computation as host machines. This way, programmers can exploit low-cost, networked computing resources, such as collections of clusters, widely available within departmental organizations, in a well-known programming environment, such as PVM, without having to tackle the problems affecting grid computing, which often ends up turning the development of parallel applications into a burdensome activity as well as penalizing application performance.

A component-based approach to build a portable and flexible middleware for metacomputing

The huge amount of computing resources in the Internet makes it possible to build meta-computers for solving large-scale problems. Despite the great availability of software infrastructures for managing such systems, metacomputer programming is often based on models that do not appear to be suitable to run applications on wide-area, unreliable, highly-variable networks of computers. In this paper, we present a customisable, Java-based middleware which provides programmers with a portable and flexible framework to run applications over a hierarchical, virtual network architecture. The middleware is designed according to a component-based approach that enables the execution behaviour of each computing node to be customised in order to satisfy application needs. The paper shows some examples of programming model customisation and demonstrates that flexibility can be achieved without significantly compromising performance.

Mobile active objects for highly dynamic distributed computing

The pervasiveness of Internet-based communication technologies is fostering new forms of distributed computing, namely, large-scale, highly decentralized computing and mobile computing. In this context, new application domains such as M-commerce, mobile multimedia, and cooperative information systems, demand for adaptive and flexible middlewares and frameworks which fully exploit logical mobility and support programmable coordination infrastructures. In this paper, we present a distributed computational model which extends an active object model by introducing the mobile active object concept in order to support a multi paradigm design approach. Mobile active objects are autonomous network-aware entities or mobile agents which coordinate to one another through on-demand installable interaction spaces featured by events. The model is embedded in ActiWare - our customizable Javabased framework for the development of highly dynamic distributed applications.

A web oriented and interactive buyer-seller watermarking protocol

This paper presents and discusses a web oriented, interactive anonymous buyer-seller watermarking protocol. In particular, the protocol enables buyers who are neither provided with digital certificates issued by trusted certification authorities (CAs) nor able to autonomously perform security actions to purchase digital contents distributed by web content providers (CPs) while keeping their identities unexposed during web transactions. The protocol also allows guilty buyers, i.e. who are responsible distributors of illegal replicas, to be unambiguously identified. Finally, the protocol has been designed so that CPs can exploit copyright protection services supplied by web service providers (SPs) in a security context. Thus, CPs can take advantage of complex protection services without having to implement them.

Designing a DRM System

The digital rights management (DRM) systems aim at protecting and enforcing the legal rights associated with the use of digital content distributed on the Internet. Most of such systems use watermarking techniques to implement the content protection. Although the effectiveness of the implemented protection strictly depends on the adopted watermarking techniques, an important role is also played by watermarking protocols. They define the scheme of the interactions that have to take place among the entities involved in the processes of content protection and Web-based distribution governed by the DRM systems. This paper presents a DRM system developed as a Web software platform to implement the copyright protection of multimedia digital content distributed on the Internet. The DRM system is based on a watermarking protocol previously developed by the authors, and has been designed as a service oriented architecture composed of a federation of coordinated Web entities that play distinct roles and interact within a trusted environment.

A PVM Extension to Exploit Cluster Grids

Workstations belonging to networked clusters cannot often be exploited since they are not provided with valid IP addresses and are hidden from the Internet by IP addressable front-end machines. The paper presents a PVM extension that enables such clustered machines hidden from the Internet to take part in a PVM computation as hosts. This way, programmers can exploit low-cost, networked computing resources widely available within departmental organizations in a well-known programming environment, such as PVM, without having to adapt their large-scale applications to new grid programming environments.

An effective and dynamically extensible DRM web platform

The digital rights management platforms (DRMps) are the web platforms employed by web content providers (CPs) to ensure the copyright protection of the digital contents they distribute on the Internet. However, the current DRMps that employ watermarking technologies to protect multimedia digital contents implement “centralized” service models in which the protection process is directly implemented by the managers of the DRMps, i.e. CPs, which are also the copyright owners. This has given rise to documented problems that nowadays affect the DRMps and make their use difficult in a web context. This paper presents a DRMp characterized by a distributed architecture that enables CPs to exploit copyright protection services supplied by web service providers (SPs) according to protection processes controlled by trusted third parties (TTPs). The proposed approach exploits web-oriented programming technologies to enable CPs and SPs to dynamically cooperate in the protection process without imposing a tight coupling among them.

Programming metasystems with active objects

The widespread diffusion of metasystems and grid environments makes it necessary to employ programming models able to well exploit a high, variable number of distributed heterogeneous resources. Many software frameworks designed for Grid computing do not address this problem. They only allow the use of existing programming libraries based on explicit message-passing communication models, often not suitable to manage the variability of a Grid. In this paper we present the customization of a component-based middleware for metacomputing, HiMM (Hierarchical Metacomputer Middleware), in order to support distributed programming based on the Active Object model provided by ProActive. This way a meta-system can be efficiently and transparently programmed by unifying the asynchronousremote method invocation model and the reflection provided by meta-objects.

An Approach to Asynchronous Object-Oriented Parallel and Distributed Computing on Wide-Area Systems

This paper presents a flexible and effective model for object-oriented parallel programming in both local and wide area contexts and its implementation as a Java package. Blending r emoteevaluation and active messages, our model permits programmers to express asynchronous, complex interactions, so overcoming some of the limitations of the models based on message passing and RPC and reducing communication costs.