GNUnet GNU‘s decentralized anonymous and censorship-resistant P2P framework.

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The Encoding for Censorship-Resistant Sharing

When GNUnet shares files, it uses a content encoding that is called ECRS, the Encoding for Censorship-Resistant Sharing. Most of ECRS is described in this research paper. ECRS obsoletes the previous ESED and ESED II encodings which were used in GNUnet before version 0.7.0.
The rest of this page assumes that the reader is familiar with the ECRS paper. What follows is a description of some minor extensions that GNUnet makes over what is described in the paper. The reason why these extensions are not in the paper is that we felt that they were obvious or trivial extensions to the original scheme and thus did not warrant space in the research report.

NBlocks

An NBlock is a signed advertisement for a namespace. The NBlock contains metadata describing the content of the namespace, in particular the identifier for the root of the namespace. The NBlock is signed with the content provder′s RSA private key. Peers can search for NBlocks in order to find out more about a namespace.

KNBlocks

GNUnet implements KNBlocks which are KBlocks that, instead of encrypting a CHK and metadata, encrypt an NBlock instead. In other words, KNBlocks enable GNUnet to find NBlocks using the global keyword search. The rationale behind KNBlocks and NBlocks is to enable peers to discover namespaces via keyword searches, and, to associate useful information with namespaces. When GNUnet finds KNBlocks during a normal keyword search, it adds the information to an internal list of discovered namespaces. Users looking for interesting namespaces can then inspect this list, reducing the need for out-of-band discovery of namespaces. Naturally, namespaces can also be referenced from directories, but KNBlocks should make it easier to advertise namespaces for the owner of the pseudonym since they eliminate the need to first create a directory.

Collections are also advertised using KNBlocks.

Copyright (C) 2002, 2003, 2004, 2005, 2006 Christian Grothoff.
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