Krista Bennett, Christian Grothoff, Tzvetan Horozov, and Ioana Patrascu

CERIAS TR 2002-23

inproceedings

This paper describes the design of a censorship-resistant distributed file sharing protocol which has been implemented on top of GNUnet, an anonymous, reputation-based network. We focus on the encoding layer of the GNUnet file-sharing protocol which supports efficient dissemination of encrypted data as well as queries over encrypted data. The main idea advocated in this paper is that simple cryptographic techniques are sufficient to engineer an efficient data encoding that can make it significantly harder to selectively censor information. Our encoding allows users to share files encrypted under descriptive keys which are the basis for querying the network for content. A key property of our encoding is that intermediaries can filter invalid encrypted replies without being able to decrypt the query or the reply. Files are stored in small chunks which are distributed and replicated automatically by the GNUnet infrastructure. Additionally, data files may be stored in plaintext or encrypted form or as a combination of both and encrypted on demand.

2002 – July – 3

Berlin

7th Australasian Conference on Information Security and Privacy

CERIAS

bennett

107-120

Springer-Verlag

Purdue University

Lecture Notes in Computer Science

2384

CERIAS, Secure Software Systems Lab

1900-01-01

- deniability - verification of encrypted reply without knowledge of the key - on-demand encryption

English

Censorship-resistant encoding content that is shared on a network with malicious participants.