What is a cookie?
“A cookie is a small file, typically of letters and numbers, downloaded onto a device when the user accesses certain websites. Cookies are then sent back to the originating website on each subsequent visit. Cookies are useful because they allow a website to recognise a user’s device.” – Text taken from ICO document ‘Guidance on the rules on use cookies and similar technologies’, dated 13 December 2011.
Broadly speaking, cookies are either ‘session-based’ or ‘persistent’. The former is deleted when you close your browser. The latter is more likely to collect a greater amount of personal information, such as browsing behaviour if so-configured, and is deleted manually or on its expiration date.
Which cookies does the MSL system include?
ASP.NET_SessionID - Stores a temporary unique identifier for your session – no other information is stored. This cookie is removed when you close your browser.
ASPXAUTH - When you are logged in, this cookie stores a value that identifies you to your site. This value is encrypted and can only be read by the server. If you use the Remember Me function this cookie remains on your computer for 3 months, otherwise it is removed when you log out of the site.
AntiXsrfToken - Implements a preventative mechanism against Cross-Site Request Forgery attacks (see https://en.wikipedia.org/wiki/Cross-site_request_forgery for further details).