Novell LINUX ENTERPRISE DESKTOP 10 SP2 - KDE 08-05-2008 Manual page 191

IMPORTANT: Establishing a Web of Trust
Encrypted communication is only secure to the extent that you can positively
associate public keys in circulation with the specified user. By cross-checking
and signing these keys, you contribute to the establishment of a Web of Trust.
For these reasons, make really sure you only sign keys you personally checked.
Select the key to sign in the key list. Select Keys > Sign Keys. In the following dialog,
designate the private key to use for the signature. An alert reminds you to check the
authenticity of this key before signing it. If you have performed this check, click Con-
tinue and enter the password for the selected private key in the next step. Other users
can now check the signature by means of your public key.
10.4.2 Trusting Keys
Normally, you are asked by the corresponding program whether you trust the key, or
rather, whether you assume it is really used by its authorized owner. This happens each
time a message needs to be decrypted or a signature must be checked. To avoid this,
edit the trust level of the newly imported key. By default, the newly imported key is
listed with a white box, meaning that no concrete value has been assigned for the trust
level. To trust a key, do the following:
1 Right-click the newly imported key to access a small context menu for the key
management.
2 Select Sign Keys. KGpg opens a dialog that asks the user to recheck the fingerprint
of the key.
3 Use Continue to access the key signing dialog.
4 Select your trust level, for example, select I Have Done Very Careful Checking.
Finish this dialog.
5 Enter your passphrase to finish the key signing process. The imported key now
appears green in the trust column.
The lower the trust level is, the less you trust the signer of the key to have checked the
true identity of the keys signed. You may be entirely sure about the signer's identity,
but he may not check other people's identities properly before signing their keys.
Encryption with KGpg 179