Cookies puts small files (known as “cookies”) onto your computer to collect information about how you use our site.

Cookies are used to:

  • measure how you use the website so it can be updated and improved based on your needs
  • remember the notifications you’ve seen so that we don’t show them to you again

GCHQ does not use cookies to identify you personally.

You will normally see a message appear on the site before we store a cookie on your computer.

Find out more about how to manage cookies.

How we use cookies

Measuring website usage

GCHQ uses the PIWIKTM analytics tool to collect data that we use to improve your experience of our website.

 The cookies we use are:





Used to prevent counting a person twice when counting how many people visit the website

1 year


Used to identify the page from which visitors have come to the website;
enables us to understand which websites generate the most traffic

1 year


Used to track how long a visitor stays on the website

1 year


Our introductory message

We are legally obliged to tell you that we use cookies on our site and gain your consent to their use. We do this via a pop-up message when you first visit We store a cookie on your computer so that we know that you have acknowledged the pop-up and the site knows not to show it again:  





Records whether or not the cookies notification pop-up has been acknowledged by the user

11 months


Our Content Management System

We use the Drupal Content Management System on this website, which also sets a number of cookies:





Allows the website to determine whether your browser is javascript compatible

Browser session


Used to determine whether the user is logged on to the site

23 days


Denial of Service Prevention

We use Web Application Firewalls to detect and block suspicious traffic that may cause a denial of service, which uses a number of cookies:

Name Purpose Duration
BNIS_x-bni-jas DDoS Prevention Browser session
x-bni-ci  DDoS Prevention Browser session
x-bni-ja DDoS Prevention Browser session
AWSELB Load Balancing Browser session


Third Party Cookies

First party cookies are those that we set for; third party cookies are cookies that originate from different websites. We do not control the setting of third party cookies, so if you are concerned you should check the policy on the third party website.

An example of a third party website we use is YouTubeTM. We have a number of videos on, and although we own (or have permission to use) them, the video content is actually streamed from YouTubeTM . You may therefore receive a YouTube cookie if you view one of our videos.