Browsing by Author "Stubblefield, Adam"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    A Security Analysis of My.MP3.com and the Beam-it Protocol
    (2000-03-08) Stubblefield, Adam; Wallach, Dan S.
    My.MP3.com is a service that streams audio in the MP3 format to its users. In order to resolve copyright concerns, the service first requires that a user prove he or she owns the right to listen to a particular CD. The mechanism used for the verification is a program called Beam-it which reads a random subset of an audio CD and interacts with the My.MP3.com servers using a proprietary protocol. This paper presents a reverse-engineering of the protocol and the client-side code which implements it. An analysis of Beam-it's security implications and speculations as to the Beam-it server architecture are also presented. We found the protocol to provide strong protection against a user pretending to have a music CD without actually possessing it, however we found the protocol to be unnecessarily verbose and includes information that some users may prefer to keep private.
  • Thumbnail Image
    Item
    Dagster: Censorship-Resistant Publishing Without Replication
    (2002-07-23) Stubblefield, Adam; Wallach, Dan S.
    In this paper we present Dagster, a new censorship-resistant publishing scheme. Unlike previous censorship-resistant schemes, Dagster does not rely on the widespread replication of data and can even be used in a single server setting. It accomplishes this by ``intertwining'' legitimate and illegitimate data, so that a censor can not remove objectionable content without simultaneously removing legally protected content. The Dagster system was designed to be as simple and efficient as possible. It increases required network traffic by a constant (but tunable) factor, but otherwise has a very low cost for both clients and servers, making it easy to scale.