SSL certificates are a tool which protects internet sites and also guarantees the confidentiality of data which was sent electronically. To achieve complete security, communication between computers is encrypted. SSL certificates are registered for a given domain name and contain information on the domain owner, their address, etc. Data is secured cryptographically, and it is unauthorised changes to it are impossible.
SSL certificates date back to 1994, when Netscape created the Secure Socket Layer protocol, used for secure transmissions of an encrypted data stream. Its effectiveness, easy use and installation, meant that it quickly found use in securing on-line banking transactions, particularly during on-line auctions and as part of on-line payment systems.