How to Use Public Key Encryption to Protect Data

Public key encryption utilizes 2 keys for encryption. The public key is used to encrypt data, and a private key is used to decrypt data. When you use public key encryption, your public key is published but the private key is secret. Anyone with a copy of your public key can encrypt data that only you can read. Public key encryption is most often used commercially on secure websites, but any Microsoft Office XP user can employ public key encryption to protect documents and emails.

Difficulty: Moderately Challenging

Instructions

Obtain and Install a Digital Certificate

1. Obtain a digital certificate from a certification authority. Click on to tools, options, security in Microsoft Outlook or Outlook Express. Click on the "get a digital id" button to be directed to a list of certification authority websites.

2. Follow the link to the certification authority's website. You must apply for the certificate and have your identity verified before it will be sent to you.

3. Open the email from the certification authority and follow the directions to install the certificate.

Use Certificates to Encrypt Email

4. Click on tools, options, security, settings in Outlook. Click the "choose" buttons to select the certificates to use to sign and encrypt your e-mail messages.

5. Ask a recipient to send you a digitally signed message to add his certificate to your contacts list. You must have a copy of the recipients digital certificate to send encrypted messages to that person. Open the message, right click the name, and click "add to contacts" or "update address." The certificate will be stored with the contact information for the recipient.

6. Open a new e-mail message, go to the view menu and click options. Check the "encrypt message contents and attachments" box and then click close. Write and send the encrypted message. Only recipients with certificates in your contacts list will be able to read the message.

Use Certificates to Encrypt Microsoft Office Files

7. Choose tools, options, security to add a digital signature or encrypted password to a Microsoft Office file.

8. Click the "digital signatures" button to add a certificate to a document. The certificate must already be installed on your computer.

9. Type in a password and click the "advanced" button to choose a cryptographic provider. Click "ok" to encrypt the password.