The most valuable information stored in iPhone, iPod Touch and iPad backups is keychains. This includes email account passwords, Wi-Fi passwords, and passwords you enter into websites and some other applications. If you encrypt the backup with iOS 4 and later, the keychain information can be transferred to the new device. With an unencrypted backup, the keychain can only be restored to the same iPhone or iPod touch. If you are restoring to a new device with an unencrypted backup, you will need to enter these passwords again.
EPPB is able to decrypt keychain data from password-protected backups (iOS4 only), if backup password is known (or recovered). Select [File] | [Apple] | [Keychain Explorer] menu item and browse for password-protected backup; you will be prompted for backup password. If password is correct, you will see all data stored in the keychain - for wireless access points (stored under Generic Passwords | AirPort); VPN passwords are also there (with "PPP Password" description):
Mail (POP3, SMTP, IMAP):
Web sites:
Press Export to save all keychain data into XML or TXT (plain text) file.