Content
- Prerequisites for
signing
- Signature
Classes
- The act of
signing
The signee (i.e. the key holder who wishes to obtain a signature
from me, the signer) must make her OpenPGP public key available on a
publicly accessible keyserver, such as the .pgp.net
servers.
The signee must prove her identity to me by way of a passport,
national ID card or a driver's licence or a credit card. The token
must feature a photographic picture of the signee.
Exceptions will be made when the signee can come up with other
means of proof of identity. However at least one of the above tokens
will stay the minimum requirement.
The signee should have prepared a strip of paper with a printout of
the output
gpg --list-keys --with-fingerprint 0xDEADBEEF
(or an equivalent command if you're not using GnuPG), where
0xDEADBEEF is the key ID of the key that is to be signed.
A hand-written sheet featuring all user IDs the signee wants me to
sign and the fingerprint will be accepted, too.
The signee should be willing to cross-sign with me.
I will sign keys using one of the three signature classes:
- Signature Class I
- Used for sign-only keys where the below challenge/response
dialogue was not possible or when signees do not wish to have
their email addresses verified in this way. The latter should
never happen, though.
- Signature Class II
- Used for all other signatures, where I don't have a strong
personal relationship with the signee.
- Signature Class III
- Used for all other signatures, where I have a strong personal
relationship with the signee.
I define a strong personal relationship as knowing the
signee outside a key signing situation.
A signature of Classes II and III always means the email
addresses were verified to belong to the signee.
A signature of Class I always means the email addresses
were not verified to belong to the signee.
The signee should sign above strip in my presence. For efficiency,
exceptions will be accepted on larger key signing parties.
After having received (or exchanged) the proof detailed in the
above, I will sign the sheet of paper myself to avoid fraud.
At home, I will prepare emails and send one to each of the mail
addresses featured in the user IDs that I was asked to sign.
Either
The emails will contain random strings and will be encrypted to the
public key whose fingerprint is printed on the paper. In the event
that the signee requires a signature only key to be signed I will
require an encryption-enabled key that lists the same addresses as the
signature only key. Failing that, the signature (if any) will only be
of Class I. I will also require replies to be signed by the key to be
certified, even if the challenge was encrypted to a different key.
Upon reception of encrypted replies, I will check the returned
random string for equality with what I sent.
User IDs that pass the above test are signed. If one of the user
IDs fails the test, a warning is sent to the rest of the user ID
addresses and the procedure retried with a new challenge at most three
times until a successful response has been received or the procedure
has been canceled by the signee.
The signed keyblock is sent to a randomly chosen, signed, user ID
address and one or more keyservers.
When not cross-signing, the signed keyblock is uploaded immediately
to a randomly chosen set of keyservers.
The signee may hint on which keyservers to use.
Or
I will sign each User ID on the key separately and email the signed
key, encrypted to the email address associated with the User ID. The
signee (who thus controls both the email address and private key) is
then able to upload the signed key to a public keyserver of their
choice (or not).
NOTE: The choice of signing method will be determined by the
signee. An exceptions will be made for larger key signing parties
where the I will determine the optimal method.
|