SSL Offloading

In a traditional environment / architecture, a client makes a request for a certain webpage. After that web server process the client request and sends a response back to the client. The modern websites and architecture do this process smartly with the help of SSL offloading.

Let ‘s start deeper to understand SSL offloading more …

What is SSL offloading?

SSL offloading is the process of relieving the webservers from the task of encryption and decryption.

There are SSL off-loader devices like Citrix NetScaler, F5. It comes with separate Application Specific Integrated processors (ASIC). This offsets the webserver ‘s task of Decryption /Encryption by limiting the SSL traffic. It performs the encryption and decryption intensive task on behalf of the web applications.

This free up the processing power of the web application servers. Now it can function to give the client request the appropriate response as quickly as possible. In a nutshell, this is how SSL offloading works.


SSL offloading has some other concepts, including SSL Accelerators & SSL load balancing.

Any modern tool that helps to improve the distribution of workload among the different available resources can be a load balancer. Limit the SSL handshaking process to itself, for example, and forward the plain text data to the least-occupied backend server.

Benefits of SSL offloading:

  • The SSL offloader unit offloads the SSL handshaking task that involves both encryption and decryption-the two main tasks that bog down the computing power of the web application.
  • The device completes the handshaking of SSL quicker than the web server. This results in the smooth loading process of the website and processing of the request at the end of the web application being considerably fast.
  • It may also aid in HTTPS inspection, reverse proxy, traffic control, persistence of cookies, etc. depending on what kind of SSL load balancer you have installed at your end.
  • HTTPS inspection is another most important point to use for SSL load-balancer. We understand how important encryption is but it also has drawback attackers hiding and encrypting the malicious code.

So, using HTTPS traffic a good HTTPS inspection rule will evade the attack. All https traffic will be checked and will be allowed to pass through the corporate network only after it is deemed good.

As the SSL / TLS traffic through it becomes important to offload and inspect every https traffic.

Types of SSL Offloading

There are two types of SSL offloading and knowing which one fits your requirement is important to you.

Web server SSL offloading:

It is a process where the system decrypts the data, sending the information to the backend servers in plain text format.

The server will then send the appropriate response based on the request from the client and forward the packet to the system.

The computer in turn, using the mounted SSL to encrypt the data and send the same to the end customer.

SSL bridging:

It is a method of decrypting the data that inspects the information that encrypts it again and sends the same to the web server backend.

The SSL certificates must be enabled in all the web servers that host the requested URL. It is then decrypted again by the web server.

The server will encrypt the response and send it to the device. The device will then decrypt it, inspect the content and encrypt it again and send the same to the end customer.