Blackberry 8520 Version 5.0 User Guide - Page 79

User Guide Messages 8. Type the contact information. 9. Press the Enter key. 10. Press the Menu key. 11. Click Save. Reset a blocked message counter 1. On the Home screen or in a folder, click the Options icon. 2. Click Security Options. 3. Click Firewall. 4. Highlight a message type. 5. Press the Menu key. 6. Click Reset Count or Reset All Counts. S/MIME-protected messages S/MIME-protected message basics About signing and encrypting messages If your email account uses a BlackBerry® Enterprise Server that supports this feature, you can digitally sign or encrypt messages to add another level of security to email messages and PIN messages that you send from your BlackBerry device. Digital signatures are designed to help recipients verify the authenticity and integrity of messages that you send. When you digitally sign a message using your private key, recipients use your public key to verify that the message is from you and that the message has not been changed. Encryption is designed to keep messages confidential. When you encrypt a message, your device uses the recipient's public key to encrypt the message. Recipients use their private key to decrypt the message. To send an encrypted PIN message, you must have a PIN and an email address for the contact in your contact list. Your device uses the email address in your contact list to locate a PGP® key or certificate for the contact. Sign or encrypt a message You can sign or encrypt email messages and PIN messages. 1. When composing a message, change the Encoding field. 2. If necessary, change the Classification field. Encrypt a message with a pass phrase Your BlackBerry® device can encrypt email messages and PIN messages using a pass phrase shared between the sender and recipient. 1. In an unsent message, set the Encoding field to Encrypt or Sign and Encrypt. 2. Press the Menu key. 77