E-Commerce Overview - Web Development and Design Foundations with XHTML - page 477

Secure Sockets Layer (SSL)
Secure Sockets Layer (SSL) is a protocol that allows data to be privately exchanged over
public networks. It was developed by Netscape and is used to encrypt data sent between
a client (usually a Web browser) and a Web server. SSL utilizes both symmetric and
asymmetric keys.

SSL provides secure communication between a client and server by using the following:

● Server and (optionally) client digital certificates for authentication
● Symmetric-key cryptography with a “session key” for bulk encryption
● Public-key cryptography for transfer of the session key
● Message digests (hash function) to verify the integrity of the transmission

You can tell that a Web site is using SSL by the protocol in the Web browser address
text box—it shows https instead of http. Also, Internet Explorer and Netscape browsers
display a lock icon when SSL is used, as shown in Figure 12.4.

Figure 12.4
The browser
indicates that SSL is
being used

FAQ

When some Web sites are displayed in a browser there is a color bar
in the address area. What's up?

If a Web site displays a color bar in the address area of the browser in addition to the lock
icons in the status bar, you know that it is using Extended Validation SSL (EV SSL). EV SSL
signifies that the business has undergone more rigorous background checks to obtain its digital
certificate, including verification that:

● the applicant owns the domain
● the applicant works for the organization
● the application has authority to update the Web site
● the organization is a valid, recognized place of business