ANNOUNCING Allmydata.org "Tahoe", the Least-Authority Filesystem, v1.0

We are pleased to announce the release of version 1.0 of the "Tahoe"
Least Authority Filesystem.

The "Tahoe" Least Authority Filesystem is a secure, decentralized,
fault-tolerant filesystem.  All of the source code is available under
a Free Software, Open Source licence (or two).

This filesystem is encrypted and distributed over multiple peers in
such a way it continues to function even when some of the peers are
unavailable, malfunctioning, or malicious.

A one-page explanation of the security and fault-tolerance properties
that it offers is visible at:

http://allmydata.org/source/tahoe/trunk/docs/about.html


We believe that this version of Tahoe is stable enough to rely on as a
permanent store of valuable data.  The version 1 branch of Tahoe will
be actively supported and maintained for the forseeable future, and
future versions of Tahoe will retain the ability to read files and
directories produced by Tahoe v1.0 for the forseeable future.

This release of Tahoe will form the basis of the new consumer backup
product from Allmydata, Inc. -- http://allmydata.com .


This is the successor to Allmydata.org "Tahoe" Least Authority
Filesystem v0.9, which was released March 13, 2008 [1].  Since v0.9
we've made the following changes:

 * Use an added secret for convergent encryption to better protect the
   confidentiality of immutable files, and remove the publically
   readable hash of the plaintext (ticket #365).

 * Add a "mkdir-p" feature to the WAPI (ticket #357).

 * Many updates to the Windows installer and Windows filesystem
   integration.


Tahoe v1.0 produces files which can't be read by older versions of
Tahoe, although files produced by Tahoe >= 0.8 can be read by Tahoe
1.0.  The reason that older versions of Tahoe can't read files
produced by Tahoe 1.0 is that those older versions require the file to
come with a publically-readable hash of the plaintext, but exposing
such a hash is a confidentiality leak, so Tahoe 1.0 does not do it.


WHAT IS IT GOOD FOR?

With Tahoe, you can distribute your filesystem across a set of
computers, such that if some of the computers fail or turn out to be
malicious, the filesystem continues to work from the remaining
computers.  You can also share your files with other users, using a
strongly encrypted, capability-based access control scheme.

Because this software is the product of less than a year and a half of
active development, we do not categorically recommend it for the
storage of data which is extremely confidential or precious.  However,
we believe that the combination of erasure coding, strong encryption,
and careful engineering makes the use of this software a much safer
alternative than common alternatives, such as RAID, or traditional
backup onto a remote server, removable drive, or tape.

This software comes with extensive unit tests [2], and there are no
known security flaws which would compromise confidentiality or data
integrity.  (For all currently known security issues please see the
Security web page: [3].)

This release of Tahoe is suitable for the "friendnet" use case [4] --
it is easy to create a filesystem spread over the computers of you and
your friends so that you can share files and disk space with one
another.


LICENCE

You may use this package under the GNU General Public License, version
2 or, at your option, any later version.  See the file "COPYING.GPL"
for the terms of the GNU General Public License, version 2.

You may use this package under the Transitive Grace Period Public
Licence, version 1.0.  The Transitive Grace Period Public Licence says
that you may distribute proprietary derived works of Tahoe without
releasing the source code of that derived work for up to twelve
months, after which time you are obligated to release the source code
of the derived work under the Transitive Grace Period Public Licence.
See the file "COPYING.TGPPL.html" for the terms of the Transitive
Grace Period Public Licence, version 1.0.

(You may choose to use this package under the terms of either licence,
at your option.)


INSTALLATION

Tahoe works on Linux, Mac OS X, Windows, Cygwin, and Solaris.  For
installation instructions please see "docs/install.html" [5].


HACKING AND COMMUNITY

Please join us on the mailing list [6] to discuss uses of Tahoe.
Patches that extend and improve Tahoe are gratefully accepted -- the
RoadMap page [7] shows the next improvements that we plan to make and
CREDITS [8] lists the names of people who've contributed to the
project.  The wiki Dev page [9] contains resources for hackers.


SPONSORSHIP

Tahoe is sponsored by Allmydata, Inc. [10], a provider of consumer
backup services.  Allmydata, Inc. contributes hardware, software,
ideas, bug reports, suggestions, demands, and money (employing several
allmydata.org Tahoe hackers and instructing them to spend part of
their work time on this free-software project).  We are eternally
grateful!


Zooko O'Whielacronx
on behalf of the allmydata.org team
March 25, 2008
San Francisco, California, USA

[1] http://allmydata.org/trac/tahoe/browser/relnotes.txt?rev=2315
[2] http://allmydata.org/trac/tahoe/wiki/Dev
[3] http://allmydata.org/trac/tahoe/wiki/Security
[4] http://allmydata.org/trac/tahoe/wiki/UseCases
[5] http://allmydata.org/source/tahoe/trunk/docs/install.html
[6] http://allmydata.org/cgi-bin/mailman/listinfo/tahoe-dev
[7] http://allmydata.org/trac/tahoe/roadmap
[8] http://allmydata.org/trac/tahoe/browser/CREDITS?rev=2345
[9] http://allmydata.org/trac/tahoe/wiki/Dev
[10] http://allmydata.com
