Florian Pestoni

Anonymous trust: digital rights management using broadcast encryption

Broadcast encryption is an active area of cryptographic research. Originally defined by Fiat and Naor, broadcast encryption refers to key management schemes that operate when the participating parties do not have a two-way communication path. We contrast that with public-key cryptography: all known public-key protocols require a handshake to establish a common key. We extend the use of broadcast encryption to solve problems that have been traditionally addressed by public-key cryptography: we discuss the xCP cluster protocol, a proposed digital rights management (DRM) system for the home entertainment network, and we illustrate a broadcast-encryption-based content distribution system, which can work without requiring any secrets in the DRM client.

Broadcast encryption's bright future

As a vehicle for content protection, broadcast encryption promises more flexible and resilient security compared with traditional public key cryptography techniques.

Virtual jukebox: reviving a classic

Recent advances in compression technology, combined with lower cost of storage and bandwidth, have made digital distribution of rich content including music not only technically feasible but also popular with a broad audience. However, limited progress has been made in the way this content is enjoyed by eyed users. We focus on the problem of playing music in a shared space, e.g, office, home, car - such that all listeners who are present share a positive music experience. Our scheme enables collaborative selection of content and pooling of content files. Users can express their preferences by contributing songs to be played and through a simple voting scheme. The system builds profiles and automatically selects content for playback, maximizing the match with the groups taste. As users vote, the system learns more about their collective preferences and can adjust the playlist accordingly, thus providing an incentive mechanism.

xCP: peer-to-peer content protection

In this article, we present a new protocol for implementing an authorized domain, a collection of devices that are equally authorized to play content. This is a new direction for content protection schemes that represents a careful balance between the needs and wants of consumers and content owners. Our protocol is a novel application of cryptographic technique known as broadcast encryption in a configuration that had not been explored previously: a peer-to-peer (P2P) network. We discuss the details of a P2P protocol based on broadcast encryption that supports and enforces renewable content protection for home networks. Several technical advantages of this protocol, including lower computational requirements, flexible network topology and support for intermittently connected devices, are given.

The Almaden Distributed Digital Library System

In this chapter we describe the architecture for the Almaden Distributed Digital Library System, which is intended to support an emerging “information marketplace”. Using a distributed server approach and accommodating heterogeneous environments, the system is designed to meet the diverse needs of the publishers, distributors, and users of scientific journal information at low cost, while protecting the information assets of the publishers and the privacy of the users. A prototype is currently being implemented in a joint effort by IBM Almaden Research Center and the Institute for Scientific Information. A pilot is planned to test the system and to explore new economic models.

eXtensible content protection

This paper describes a proof of concept implementation of xCP, a content protection scheme for home networks.