HTTP is not enough for the performance of several tasks such as the acceptance of Online payments and other sensitive information. It in not a secure method for  communication of any sensitive information as everything is sent via wires in clear text. It is very easy to gain  access to the network through the ISP.

Always take care not to transmit any password related information without any additional security measures. To do this, you need to know about encryption. To add encryption to your site, SSL is used which is a standardized method of encryption.

What is SSL?
Secure Sockets Layer, or SSL, is a method of using cryptography to ensure a secure communication between the server and the client. In this way, the data cannot be tampered with. SSL works by the use of a variety of encryption methods. SSL certificate are used to certify that the site is real, thus help to prevent imitations.

On combining it with HTTP, it becomes HTTPS, that is Secure HTTP. HTTPS is a powerful way to send sensitive information through the web browsers. The browsers develop small padlock symbols, to certify that the website is secure for transmission of any critical information.

However, SSL cannot be considered as the complete security package. It is just a way to keep the data secure as long as the data is traveling across the Internet. If you store your data in an encrypted database in your server, anyone who has access to it, can easily retrieve the data.

Levels of Encryption
SSL encryption has three main levels, that is, 40-bit, 128-bit and 256-bit.

40-bit SSL is now outdated and not used anymore. Always aim to use a minimum of 128-bit, or preferably 256-bit. The value of the goods that you sell will determine which one you can afford.

Using SSL?
Before using SSL, it is necessary to get certified. To get certified, you need to buy a SSL certificate from any trusted certificate authority. Some of the best certificate authorities are VeriSign, Thawte and GeoTrust. However, these authorities charge a much higher amount as compared to others.

This process is quite similar to purchase of a domain name. In fact, a number of domain registrars resell their certificates. In case you are looking for the certificates at a lower price, then you can get it from the domain registrars.