How SSL Offloading Boosts Performance and Simplifies Traffic Management

What is SSL Offloading?

Historically, SSL/TLS added latency to connections because each handshake and the subsequent encryption/decryption required extra processing, which could slow down websites. To alleviate this load, SSL offloading moves the cryptographic work to dedicated ASIC processors or load balancers, freeing application servers to focus on their primary tasks.

The benefits of SSL offloading include reducing the CPU burden on application servers, conserving server resources, and enabling additional features such as HTTPS inspection, reverse proxying, cookie persistence, and traffic management. It also facilitates traffic inspection, which is increasingly important for security because attackers can hide malicious activity within encrypted HTTPS streams.

Advantages of SSL Offloading

Offloads extra tasks from application servers, allowing them to focus on core functions.

Saves resources on those servers.

Depending on the load balancer, it can provide HTTPS inspection, reverse proxy, cookie persistence, traffic management, and more.

When an organization reaches a certain scale, the ability to inspect HTTPS traffic becomes almost mandatory, and SSL offloading is one of the most effective ways to achieve this.

How Does SSL Offloading Work?

There are two common approaches: SSL termination and SSL bridging.

SSL Termination

In SSL termination, the load balancer or proxy acts as the SSL terminator. Clients connect to the terminator over HTTPS, but the connection between the terminator and the application server uses plain HTTP. The secure client‑to‑terminator link remains protected, while the internal traffic is unencrypted, reducing CPU load on the server.

SSL Bridging

SSL bridging is similar to termination, but after the load balancer receives the encrypted request, it re‑encrypts the traffic before forwarding it to the application server, preserving end‑to‑end encryption while still offloading the initial handshake.

Both methods enable traffic inspection and can handle large volumes of network traffic efficiently. However, encryption remains a CPU‑intensive task; as key sizes grew from 1024‑bit to 2048‑bit RSA, CPU usage increased 4–7×, prompting a shift toward elliptic‑curve cryptography.

Should You Consider SSL Offloading?

The decision depends on your site’s scale and requirements. High‑traffic media sites like ESPN or CNN benefit greatly from load balancers with SSL offloading, while a small local business website may handle TLS 1.3 directly on its server without additional hardware.

from: https://www.racent.com/blog/ssl-offloading-bridging-termination