The Monkeysphere project's goal is to extend the web of trust model and other
features of OpenPGP to other areas of the Internet to help us securely identify
each other while we work online.

Specifically, the Monkeysphere is a framework to leverage the OpenPGP web of
trust for OpenSSH authentication. In other words, it allows you to use your
OpenPGP keys when using secure shell to both identify yourself and the servers
you administer or connect to.  OpenPGP keys are tracked via GnuPG, and added to
the authorized\_keys and known\_hosts files used by OpenSSH for connection
authentication.

[[bugs]] | [[download]] | [[news]] | [[documentation|doc]]

## Conceptual overview ##

Everyone who has used secure shell is familiar with the prompt given the first
time you login, asking if you want to trust the server's fingerprint.  In
addition, many of us take advantage of OpenSSH's ability to use RSA or DSA keys
for authenticating to a server, rather than relying on a password exchange.

[OpenSSH](http://openssh.com/) already provides a functional way for managing
the RSA and DSA keys required for these interactions. However, it lacks any
type of [Public Key Infrastructure
(PKI)](http://en.wikipedia.org/wiki/Public_Key_Infrastructure).

The basic idea of the Monkeysphere is to create a framework that uses
[GnuPG](http://www.gnupg.org/)'s keyring manipulation capabilities and public
keyservers to generate files that OpenSSH will accept and handle as intended.

This offers users of OpenSSH an effective PKI, including the possibility for
key transitions, transitive identifications, revocations, and expirations.  It
also actively invites broader participation in the
[OpenPGP](http://en.wikipedia.org/wiki/Openpgp) [web of
trust](http://en.wikipedia.org/wiki/Web_of_trust).

Under the Monkeysphere, both parties to an OpenSSH connection (client and
server) have a responsibility to explicitly designate who they trust to certify
the identity of the other party. This trust designation is explicitly indicated
with traditional GPG keyring trust model. No modification is made to the SSH
protocol on the wire (it continues to use raw RSA public keys), and it should
work with unpatched OpenSSH software.

Monkeysphere does not modify ssh in any way, and ssh can be used "out
of the box".  Monkeysphere is a set of tools that manages keys in the
known\_hosts and authorized\_keys files that ssh uses for connection
authentication.

## Philosophy ##

Humans (and
[monkeys](http://www.scottmccloud.com/comics/mi/mi-17/mi-17.html))
have innate capacity to keep track of the identity of a finite number
of people. After our social sphere exceeds several dozen or several
hundred (depending on the individual), our ability to remember and
distinguish people begins to break down. In other words, at a certain
point, we can't know for sure that the person we ran into in the
produce aisle really is the same person who we met at the party last
week.

For most of us, this limitation has not posed much of a problem in our
daily, off-line lives.  With the Internet, however, we have an ability
to interact with vastly larger numbers of people than we had
before. In addition, on the Internet we lose many of our tricks for
remembering and identifying people (physical characteristics, sound of
the voice, etc.).

Fortunately, with online communications we have easy access to tools
that can help us navigate these problems.
[OpenPGP](http://en.wikipedia.org/wiki/Openpgp) (a cryptographic
protocol commonly used for sending signed and encrypted email
messages) is one such tool. In its simplest form, it allows us to
sign our communication in such a way that the recipient can verify the
sender.

OpenPGP goes beyond this simple use to implement a feature known as
the [web of trust](http://en.wikipedia.org/wiki/Web_of_trust). The web
of trust allows people who have never met in person to communicate
with a reasonable degree of certainty that they are who they say they
are. It works like this: Person A trusts Person B. Person B verifies
Person C's identity.  Then, Person A can verify Person C's identity.

The Monkeyshpere's broader goals are to extend the use of OpenPGP from
email communications to other activities, such as:

 * conclusively identifying the remote server in a remote login session
 * granting access to servers to people we've never directly met

## Links ##

* [OpenSSH](http://openssh.com/)
* [GnuPG](http://www.gnupg.org/)
* [OpenPGP RFC 4880](http://tools.ietf.org/html/rfc4880)
* [URI scheme for SSH, RFC draft](http://tools.ietf.org/wg/secsh/draft-ietf-secsh-scp-sftp-ssh-uri/)


----

This wiki is powered by [ikiwiki](http://ikiwiki.info).