Online Data Encryption

If you're going to make an online purchase using a credit card, you need to be at a website that is encrypted, which is a site that has one of those small lock icons in the corner of your browser. Encrypted websites are what make shopping online safe.

You won't always see that small lock icon. The true blue way to tell if you're at an encrypted site is the beginning of the URL. Instead of reading "http" it should read "https."

When computers talk to each other they generally use two types of encryption (and they use these methods together): public key and symmetric key.

You should be familiar with these words when shopping online:

• Public key: Your computer gives a key to breaking a code to any computer that has a certain digital certificate.
• Digital certificates are given to websites trusted by independent sources.
• Symmetric key: A secret code that your computer creates and that is given to only one other computer.

When you make an online purchase, your computer registers that the merchandiser's computer has a digital certificate. Because of this, your computer will give the merchandiser's computer your public key. Then your computer creates a symmetric key and gives it to the merchandiser's computer through the public key encryption (read as: only computers with your public key, watching your computer at that time, will be able to decode your symmetric key). Then your computer encrypts your data (usually a credit card number) using your symmetric key and sends it to the merchandiser's computer. The merchandiser reads the information and then throws away the symmetric key and public key, never to be used by your computer again.