On July 31st Facebook announced that they have enabled secure browsing by default. More and more companies such as Google, Twitter and PayPal have started to switch to always on SSL/TLS to ensure more secure browsing. And the growth of HTTPS use is likely to continue.
Number of Sites With Valid Certificates Part of Netcraft's SSL Server Survey
This sounds all well and good. However, as is often the case on the web this trend has performance implications.
Instead of outlining the web and mobile performance implication of SSL/TLS here, I suggest you read Ilya Grigorik's excellent Browser Networking book which includes a great section on TLS.
One thing I do want to highlight though is the fact that the connection setup for SSL/TLS requires up to two additional round trips to establish a connection:
Source: Microsoft Technet
As many readers will know, these extra round trips can have a significant performance impact - particularly on high latency networks or if the server is far away from the client. You might end up with a US partner trying to log into a secure partner portal that is hosted in the EU. This is what it would look like if we tested that page using Webpagetest (Dulles, VA - IE 9 - Cable). Not exactly what you would call blazing fast.
One of the ways to optimize SSL/TLS connection establishment is a technique called Early Termination (ET). ET simply means getting your servers as close to your end-users as possible to reduce round trip latency. This is one of Akamai's core capabilities and a large number of our clients leverage it.
If we look at the same page above after they moved onto the Akamai Intelligent Platform we can see a significant performance improvement:
And, if we take this a step further and look at a whole transaction and the associated SSL time in a synthetic testing tool such as Gomez, we can easily spot the likely origin region but also the significant value Akamai can bring to the table in terms of performance improvement for secure transactions.
Further, as protocols like SPDY (which are primarily implemented over HTTPS) become more commonplace, early termination becomes even more important to deliver fast, quality experiences to your end-users.
That is why early termination is not always a bad thing...
Lorenz Jakober is a Senior Product Marketing Manager at Akamai