Ian Clarke
and Scott G. Miller
Uprizer
Theodore W. Hong
Imperial College of Science,
Technology, and Medicine
Oskar Sandberg
and Brandon Wiley
Freenet Project Inc.
Protecting Free
Expression Online
with Freenet
Freenet uses a decentralized P2P architecture to create an
uncensorable and secure global information storage system.
T
he growth of censorship and ero-
sion of privacy on the Internet
increasingly threatens freedom of
expression in the digital age. Personal
information flows are becoming subject
to pervasive monitoring and surveillance,
and various state and corporate actors are
trying to block access to controversial
information and even destroy certain
materials altogether. Recent incidents
such as the publication of Monica Lewin-
sky’s deleted personal e-mails in a U.S.
congressional report further point to an
unprecedented level of intrusion into pri-
vate life.
1
These trends cause concern not
only to whistleblowers and political dis-
sidents, but to anyone disturbed by the
thought of others reading their e-mail or
following their Web activities.
Fortunately, concurrent advances in
the power of personal computers have
made it possible to develop peer-to-peer
technologies to respond to these chal-
lenges. Our project, Freenet, is a distrib-
uted information storage system
designed to address information priva-
cy and survivability concerns.
2
A beta
version of the software is currently
available under open source at http://
www.freenetproject.org/.
In simulations of up to 200,000 nodes,
Freenet has proved scalable and fault tol-
erant. It operates as a self-organizing P2P
network that pools unused disk space
across potentially hundreds of thousands
of desktop computers to create a collab-
orative virtual file system. To increase
network robustness and eliminate single
points of failure, Freenet employs a com-
pletely decentralized architecture. Given
that the P2P environment is inherently
untrustworthy and unreliable, we must
assume that participants could operate
maliciously or fail without warning at
any time. Therefore, Freenet implements
strategies to protect data integrity and
prevent privacy leaks in the former
instance, and provide for graceful degra-
dation and redundant data availability in
the latter. The system is also designed to
adapt to usage patterns, automatically
replicating and deleting files to make the
most effective use of available storage in
response to demand.
40 JANUARY • FEBRUARY 2002 http://computer.org/internet/ 1089
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7801/02/$17.00 ©2002 IEEE IEEE INTERNET COMPUTING
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