This article describes how to verify PGP Keys in PGP Desktop 10.
Signing a Public KeyWhen you create a keypair, the keys are automatically signed. Similarly, once you are sure a key belongs to someone, you can sign that person's public key, indicating you are sure it is verified.
|Note:Select the Allow signature to be exported checkbox, to allow your signature to be exported with this key.
An exportable signature is one that is allowed to be sent to servers and travels with the key whenever it is exported, such as by dragging it to an email message. The checkbox provides a shorthand means of indicating that you wish to export your signature.
Changing the Trust level for a PGP KeypairAfter importing a keypair from backup, the key is not Verified and is not available for encryption or decryption. To enable the key, the trust level must be changed on the key properties of the key.
|Note: If you are changing the trust level for a keypair, you can select None or Implicit. Only keypairs that you are importing from backup or from another computer of yours need to have their trust set to Implicit; when you create a keypair, its trust is automatically set to Implicit.
If you are granting trust for a public key, you can select None, Marginal, or Trusted.