The Keychain Access control panel allows you to view and manage your passwords and digital certificates, which are stored in a secure database called a Keychain. Items in a Keychain are protected using a single password. You can unlock your Keychain by supplying this password, which makes the certificates and passwords contained within that Keychain available to Keychain-aware programs. A Keychain can simplify your use of local area networks and the Internet by automatically logging you in to Web sites, file servers, Internet service providers, and other services which require authentication.
When an application attempts to obtain information stored in your Keychain, you may see a dialog box that asks you to approve that application's access to the Keychain. This dialog box may seem like a nuisance, but it is intended to help protect your data from being accessed by programs written for malicious purposes. When you are asked whether to allow an application to access your Keychain, pay attention to the name of the program that is requesting the access. If the application is one that you do not recall starting, or if you did not expect the application to require access to your Keychain, you should disallow access.
Apple File Security
The Apple File Security program allows you to encrypt and decrypt files that you want to keep private. By using the "Encrypt" Finder menu selection, or by dropping files onto the "Apple File Security" application, you can encrypt a file with a passphrase that you provide. You can choose to automatically store this passphrase in your Keychain.
IMPORTANT There is no way to decrypt the file without the passphrase! Apple Computer, Inc. is unable to retrieve a forgotten passphrase. You should always make sure you remember the passphrase used to encrypt your files.
When a file is encrypted with Apple File Security, the file's icon changes: a key "badge" appears on the existing file icon. This badge indicates that the file is encrypted. If you want to view the contents of the file, simply double-click the icon; this tells Apple File Security to decrypt the file. If you have stored the passphrase in your Keychain, Apple File Security attempts to access the Keychain to retrieve the passphrase. If the password is not found in the Keychain, you are asked to provide the passphrase. Once the passphrase is obtained, AFS saves the decrypted file to your disk and removes the encrypted version. After the file is decrypted, its icon no longer displays the key badge. If, after viewing the file, you want the file to be encrypted again, you must use the Finder "Encrypt" menu item or drop the file onto the Apple File Security application to be re-encrypted.
Apple Verifier
The Apple Verifier can be used to ensure that a file you have received is the same file the author intended you to get; that is, the file has not been corrupted or changed in any way. Files signed using the Apple File Signer (available in the Security Software Developers Kit) include a digital certificate and a signature. The Apple Verifier uses these tools to determine who originally created a file and to make sure that the file hasn't been corrupted. This verification process can help you avoid running applications containing viruses. While this doesn't take the place of using virus protection/detection software, it does give you a chance to detect viruses before they are "set free" on your system.
