Welcome to Tahoe-LAFS!
======================
-Welcome to `Tahoe-LAFS <http://tahoe-lafs.org>`_, the first
+Welcome to `Tahoe-LAFS <http://tahoe-lafs.org>`_, the first
decentralized storage system with *provider-independent security*.
What is "provider-independent security"?
========================================
-Every seller of cloud storage services will tell you that their service
-is "secure". But what they mean by that is something fundamentally
-different from what we mean. What they mean by "secure" is that after
-you've given them the power to read and modify your data, they try
-really hard not to let this power be abused. This turns out to be
-difficult! Bugs, misconfigurations, or operator error can accidentally
-expose your data to another customer or to the public, or can corrupt
-your data. Criminals routinely gain illicit access to corporate
-servers. Even more insidious is the fact that the employees themselves
-sometimes violate customer privacy out of carelessness, avarice, or
-mere curiousity. The most conscientious of these service providers
+Every seller of cloud storage services will tell you that their service
+is "secure". But what they mean by that is something fundamentally
+different from what we mean. What they mean by "secure" is that after
+you've given them the power to read and modify your data, they try
+really hard not to let this power be abused. This turns out to be
+difficult! Bugs, misconfigurations, or operator error can accidentally
+expose your data to another customer or to the public, or can corrupt
+your data. Criminals routinely gain illicit access to corporate
+servers. Even more insidious is the fact that the employees themselves
+sometimes violate customer privacy out of carelessness, avarice, or
+mere curiousity. The most conscientious of these service providers
spend considerable effort and expense trying to mitigate these risks.
-What we mean by "security" is something different. *The service
-provider never has the ability to read or modify your data in the first
-place -- never.* If you use Tahoe-LAFS, then all of the threats
-described above are non-issues to you. Not only is it easy and
-inexpensive for the service provider to maintain the security of your
-data, but in fact they couldn't violate its security if they tried.
+What we mean by "security" is something different. *The service
+provider never has the ability to read or modify your data in the first
+place -- never.* If you use Tahoe-LAFS, then all of the threats
+described above are non-issues to you. Not only is it easy and
+inexpensive for the service provider to maintain the security of your
+data, but in fact they couldn't violate its security if they tried.
This is what we call *provider-independent security*.
-This guarantee is integrated naturally into the Tahoe-LAFS storage
-system and doesn't require you to perform a manual pre-encryption step
-or cumbersome key management. (After all, having to do cumbersome
-manual operations when storing or accessing your data would nullify one
-of the primary benefits of using cloud storage in the first place --
+This guarantee is integrated naturally into the Tahoe-LAFS storage
+system and doesn't require you to perform a manual pre-encryption step
+or cumbersome key management. (After all, having to do cumbersome
+manual operations when storing or accessing your data would nullify one
+of the primary benefits of using cloud storage in the first place --
convenience.)
Here's how it works:
.. image:: http://tahoe-lafs.org/~zooko/network-and-reliance-topology.png
-A "storage grid" is made up of a number of storage servers. A storage
-server has direct attached storage (typically one or more hard disks).
-A "gateway" uses the storage servers and provides access to the
+A "storage grid" is made up of a number of storage servers. A storage
+server has direct attached storage (typically one or more hard disks).
+A "gateway" uses the storage servers and provides access to the
filesystem over HTTP(S) or (S)FTP.
-Users do not rely on storage servers to provide *confidentiality* nor
-*integrity* for their data -- instead all of the data is encrypted and
-integrity-checked by the gateway, so that the servers can neither read
+Users do not rely on storage servers to provide *confidentiality* nor
+*integrity* for their data -- instead all of the data is encrypted and
+integrity-checked by the gateway, so that the servers can neither read
nor modify the contents of the files.
-Users do rely on storage servers for *availability*. The ciphertext is
-erasure-coded and distributed across ``N`` storage servers (the default
-value for ``N`` is 10) so that it can be recovered from any ``K`` of
-these servers (the default value of ``K`` is 3). Therefore only the
-simultaneous failure of ``N-K+1`` (with the defaults, 8) servers can
+Users do rely on storage servers for *availability*. The ciphertext is
+erasure-coded and distributed across ``N`` storage servers (the default
+value for ``N`` is 10) so that it can be recovered from any ``K`` of
+these servers (the default value of ``K`` is 3). Therefore only the
+simultaneous failure of ``N-K+1`` (with the defaults, 8) servers can
make the data unavailable.
-In the typical deployment mode each user runs her own gateway on her
-own machine. This way she relies on her own machine for the
+In the typical deployment mode each user runs her own gateway on her
+own machine. This way she relies on her own machine for the
confidentiality and integrity of the data.
-An alternate deployment mode is that the gateway runs on a remote
-machine and the user connects to it over HTTPS or SFTP. This means
-that the operator of the gateway can view and modify the user's data
-(the user *relies on* the gateway for confidentiality and integrity),
-but the advantage is that the user can access the filesystem with a
-client that doesn't have the gateway software installed, such as an
+An alternate deployment mode is that the gateway runs on a remote
+machine and the user connects to it over HTTPS or SFTP. This means
+that the operator of the gateway can view and modify the user's data
+(the user *relies on* the gateway for confidentiality and integrity),
+but the advantage is that the user can access the filesystem with a
+client that doesn't have the gateway software installed, such as an
Internet kiosk or cell phone.
Access Control
==============
-There are two kinds of files: immutable and mutable. Immutable files
-have the property that once they have been uploaded to the storage grid
-they can't be modified. Mutable ones can be modified. A user can have
-read-write access to a mutable file or read-only access to it (or no
+There are two kinds of files: immutable and mutable. Immutable files
+have the property that once they have been uploaded to the storage grid
+they can't be modified. Mutable ones can be modified. A user can have
+read-write access to a mutable file or read-only access to it (or no
access to it at all).
-A user who has read-write access to a mutable file or directory can
-give another user read-write access to that file or directory, or they
-can give read-only access to that file or directory. A user who has
-read-only access to a file or directory can give another user read-only
+A user who has read-write access to a mutable file or directory can
+give another user read-write access to that file or directory, or they
+can give read-only access to that file or directory. A user who has
+read-only access to a file or directory can give another user read-only
access to it.
-When linking a file or directory into a parent directory, you can use a
-read-write link or a read-only link. If you use a read-write link,
-then anyone who has read-write access to the parent directory can gain
-read-write access to the child, and anyone who has read-only access to
-the parent directory can gain read-only access to the child. If you
-use a read-only link, then anyone who has either read-write or
-read-only access to the parent directory can gain read-only access to
+When linking a file or directory into a parent directory, you can use a
+read-write link or a read-only link. If you use a read-write link,
+then anyone who has read-write access to the parent directory can gain
+read-write access to the child, and anyone who has read-only access to
+the parent directory can gain read-only access to the child. If you
+use a read-only link, then anyone who has either read-write or
+read-only access to the parent directory can gain read-only access to
the child.
-For more technical detail, please see the `the doc page
+For more technical detail, please see the `the doc page
<http://tahoe-lafs.org/trac/tahoe-lafs/wiki/Doc>`_ on the Wiki.
Get Started
License
=======
-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
-<../COPYING.GPL>`_ for the terms of the GNU General Public License,
+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
+<../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 or, at your option, any later version. The
-Transitive Grace Period Public Licence has requirements similar to the
-GPL except that it allows you to wait for up to twelve months after you
-redistribute a derived work before releasing the source code of your
-derived work. See the file `COPYING.TGGPL <../COPYING.TGPPL.html>`_ for
+You may use this package under the Transitive Grace Period Public
+Licence, version 1 or, at your option, any later version. The
+Transitive Grace Period Public Licence has requirements similar to the
+GPL except that it allows you to wait for up to twelve months after you
+redistribute a derived work before releasing the source code of your
+derived work. See the file `COPYING.TGGPL <../COPYING.TGPPL.html>`_ for
the terms of the Transitive Grace Period Public Licence, version 1.
-(You may choose to use this package under the terms of either licence,
+(You may choose to use this package under the terms of either licence,
at your option.)
-
projects / tahoe-lafs / tahoe-lafs.git / commitdiff