Secure Sockets Layer (SSL) ensures save electronical communication via internet. SSL is a protocol for encrypting information that codifies your personal data. For instance, this is used for securing credit cards - it makes it impossible for third parties to see your details. Combined with the Secure Electronic Transaction system (SET), accredited dealer can be authorized, which offers e-commerce on a very high security Level. SSL was developed in the 90s to avoid eavesdropping and data abuse - numerous versions later the newest version is called Transport Layer Security (tls) and succeeds SSL.
Kaeo, Merike. Designing Network Security. Indianapolis, IN: Cisco, 2004. Print.