Encryption is an essential tool for lawyers handling confidential information. Now, a new Firefox plug-in called freenigma enables you to send and receive encrypted e-mail using browser-based e-mail services such as Google Mail, Yahoo! Mail and Hotmail. The free plug-in adds a toolbar that appears when you log in to the e-mail service. Draft an e-mail then click the “encrypt” button in the toolbar and then send your message. To decrypt your message, the recipient must also have the plug-in and click “decrypt” on the toolbar. Encryption and decryption occur within your browser, although your contacts and trusted persons are managed on the company’s server.

Because the service is in beta, you must go to the site and request an invitation in order to register. Once registered, you can use the plug-in with multiple Web e-mail accounts. Also, you can invite colleagues to use it and send them encrypted e-mails as soon as they accept your invitation.