You have noticed a padlock icon at the bottom of certain web pages. It indicates that the page uses the SSL protocol (a data transfer security standard that encrypts data and authenticates the server and the integrity of the message) or the TLS protocol. This symbol indicates that all information, most notably banking details, is secured.
To be sure that these pages are indeed protected by SSL, you can also check the site's URL, which must begin https://, the 's' indicating that this security system is in force. You can also click the padlock in the browser bar to view the identity of the Web site owner and also check that it comes from a valid Certificate Authority. This digital certificate is a document that an organization provides from its Web site to confirm their identity, and to enable a secure connection.
For more information, you can visit ENISA, The European Network and Information Security Agency at http://www.enisa.europa.eu/.