As more and more people send confidential information via e-mail, it is becoming increasingly important to know that your messages cannot be intercepted and read by anyone other than the intended recipient. It is equally important to know that documents sent by e-mail such as checks and credit cards cannot be forged.
By using "digital IDs" with Outlook Express, you can prove your identity in electronic transactions, similar to showing your driver�s license when you cash a check. You can also use your digital ID to encrypt messages to keep them private. Digital IDs incorporate the S/MIME specification for secure electronic mail.
A digital ID is composed of a "public key," a "private key," and a "digital signature." When you send your digital ID to others, you are actually giving them your public key, so they can send you encrypted mail which only you can decrypt and read with your private key.
The digital signature component of a digital ID is your electronic identity card. The digital signature tells the message recipient that the message actually came from you and has neither been forged nor tampered with.
Before you can start sending encrypted or digitally signed messages, you must obtain a digital ID and set up your mail account to use it. If you are sending encrypted messages, your address book must contain a digital ID for the recipient.
Digital IDs are issued by an independent certifying authority. When you apply for a digital ID from a certifying authority's Web site, they have a process to verify your identity before issuing an ID. There are different classes of digital IDs, each one providing a different level of credibility. For more information, use the Help at the certifying authority's Web site.
To get someone else's digital ID, they can send you digitally signed mail (which will include their ID); you can search through the database on a certifying authority's Web site; some directory services also list digital IDs along with other properties.