What Is SSL Offloading and How It Works

SSL (Secure Sockets Layer) certificates are given to a website to make sure that the website is secured and won’t fall prey to malicious hackers. Since this process involves hitting a server continuously, the process of SSL offloading is performed to remove SSL-based encryption from incoming.

This process is designed specifically for the acceleration of SSL, known as SSL acceleration. SSL offloading software processes both encryption and decryption, both of which make the web-server slow.  

SSL Offloading 

Every web browser is compatible with SSL; this makes SSL traffic very common. SSL offloading is done so that encryption is shifted from the web-server to relieve it of potential work. This process can even include a completely separate machine or different processing devices that could be installed on the same machine.

There two different ways in which SSL Offloading can be done include:

• SSL Termination
• SSL Bridging

SSL termination refers to the process that occurs at the server end of the SSL (Secure Sockets Layer) connection (i.e. the place where the data traffic gets encrypted from an unencrypted form). The data, which comes first, is sent to a device that encrypts the decrypted information. If the information comes in an encrypted form, then the information is forwarded without any processing from the web-server. This is the quickest and most efficient form of offloading.

You may also like: What Is SSL? How Do SSL Certificates Work?

SSL bridging is also known as SSL initiation and is the task performed by a device at the edge of any network (i.e. it first decrypts the SSL traffic and then re-encrypts and sends it to the web-server. This process also works in the opposite direction).

Bridging is very important, as it helps in knowing whether the SSL encrypted data is secure or not. There are mainly three types of SSL bridging — HTTPS to HTTPs, HTTPS to HTTP, and HTTP to HTTPS. 

Benefits of SSL Offloading

SSL offloading is attractive for many applications. One of the main benefits is that the web-server no longer has to process SSL decryption and encryption and therefore can reallocate resources previously used for SSL decryption and encryption towards other, more important and common problems.

Since the web-server does not have to decrypt and encrypt information, the resources are free to help increase the speed of the website, thereby making the website more efficient in handling user needs.

Cons of SSL Offloading

Along with some very beneficial advantages, SSL Offloading also has some serious disadvantages. The main risk involved with SSL Offloading is that data is transferred in an unencrypted format while moving from an off-loader to a web-server. 

Though this process is mostly considered to be safe, due to the internal involvement of the system, which is protected by Firewalls, if the firewall’s location is on the edge of the network, then it carries with it a high risk, as the unencrypted data can be easily compromised.

If any of the clients who are connected to the web-server via SSL will undoubtedly believe that the data will travel through an encrypted form throughout its journey to the server as they may lack technical knowledge regarding SSL Offloading.

If there is a breach of data while data is in transit from the SSL off-loader to the web-server, the client can even legally sue the organization handling their data if the confidentiality or the sensitivity of the data is compromised.

Further Reading

• DZone Trend Report: DevSecOps.
• Authentication and Authorization: Mastering Security.