SSL SECURE SOCKETS LAYER

From... http://www.globalsign.com/ssl-information-center/what-is-an-ssl-certific...
SSL Certificates are small data file that digitally bind a cryptographic key to an organization’s details. When installed on a webserver, it activates the padlock, https (over port 443) and allows secure connections from a webserver to a browser. Typically SSL is used to secure credit card transactions, data transfer, logins and more recently is becoming the norm when securing browsing of social media sites. An SSL Certificate binds together:
Your domain name, server name or hostname
Your organizational identity (i.e. company name) and location
An organization needs to install the SSL Certificate onto its web server to initiate secure sessions with browsers. Depending on the type of SSL Certificate applied for, the organization will need to go through differing levels of vetting. Once installed, it is possible to connect to the website over https://www.domain.com, as this tells the server to establish a secure connection with the browser. Once a secure connection is established all web traffic between the web server and the web browser will be secure. Browsers tell visitors a website is SSL secure via several visiual indicators:
 
 From...      http://drupal.org/project/uc_authorizenet_simdpm
https://account.authorize.net/help/Merchant_Interface_RoboHelp_Project.h...
Advanced Integration Method (AIM)
AIM provides the highest level of transaction security and is the preferred method of integrating a website to the payment gateway for Card Not Present (CNP) merchants. AIM offers the most flexible integration, allowing you to:

• Host your own secure payment form and receipt page;
• Send transactions to the payment gateway using an end to end Secure Sockets Layer (SSL) connection;
• Use transaction key authentication for ultimate security.

View the AIM Implementation Guide     HTML  |   PDF
Download sample code here.