SSL is used to transmit private information over the Internet, and uses two keys to encrypt or code the data The two keys are the private and pubic keys needed to transmit data over the SSL protocol. When data is encrypted, the program uses one key to encrypt the data. The other key — it can work both ways — decrypts the data. If the server sends a public key to encrypt the data, the correct private key from the SSL protocol must decrypt the data. The longer the key — or the more bits in the key, the harder it is to manually decrypt the message. Since the protocol creates a pair of keys for each message, only you and the person you are sending the information to has the keys. You may not personally know the person receiving the information, but you know that only that person can decrypt the message since you and the person you are sending the message to are the only two people with the keys. The keys use a certificate. A root certificate, which contains information about the person you are sending information to — in this example, we will use a retailer — the retailer has a certificate on its server.