HTTP Cookies

Contents

What are cookies?

Simplistically stated, HTTP cookies are small text files stored on the visitor's computer, smartphone, etc. that are generated by some websites to store various information about visits to that website.

Types of cookies

First-party cookies
First-party cookies are issued by the website you are directly visiting. For example, if you are visiting http://billing.nettally.com, and a cookie is generated by that site, it is a first-party cookie.
An example of a useful first-party cookie would be one generated by the National Weather Service website (http://www.weather.gov) that stores a default location you enter on the website so each time you visit the website, it automatically displays content customized for that location rather than displaying generic weather information every time you visit the site.
Third-party cookies
Third-party cookies are issued by a website other than the website you are directly visiting. For example, if you are visiting http://www.cnn.com, and content displayed within www.cnn.com from http://ads.example.com or http://somethingelse.cnn.com generates a cookie, it is a third-party cookie.
Session cookies
Session cookies are issued by websites to maintain session state -- when certain information needs to be maintained throughout an active session with a website as the visitor moves throughout the site.
Websites involving online banking, e-commerce (shopping carts), web-based email systems (webmail), etc. are examples of websites that use session cookies in order to maintain an authenticated session, maintain a list of active shopping cart items, etc.

Options for allowing and blocking cookies

Modern web browsers allow users to customize cookie handling to varying degrees depending on the features available within the web browser. These features may include any of the following for first-party and/or third-party cookies:

Cookie handling exceptions

The instructions below show how to always allow cookies from anything.nettally.com by adding it as an allowed exception. Adding nettally.com automatically includes anything.nettally.com, such as secure.nettally.com, stopspam.nettally.com, etc.

Microsoft Internet Explorer 11, 10, 9, 8

  1. Click Tools then Internet Options.
  2. Click on the Privacy tab.
  3. Click the Sites button.
  4. Type nettally.com in the Address of website field and click the Allow button.
  5. Click OK.
  6. Click OK.

Mozilla Firefox

The instructions below are based on Firefox 63 for Windows, released 2018-10-23. Firefox Releases

  1. From within Firefox, click on or enter the following URI into the address field at the top and hit Enter on the keyboard:
    about:preferences#privacy
  2. In the Cookies and Site Data section, click the Exceptions... button.
    1. Type nettally.com in the Address of website field and click the Allow button.
    2. Click Save Changes.

Google Chrome

The instructions below are based on Chrome 70 for Windows, released 2018-10-16. Chrome Releases

  1. From within Chrome, click on or enter the following URI into the address field at the top and hit Enter on the keyboard:
    chrome://settings/content/cookies
  2. Click the Add button next to Allow.
  3. Type nettally.com into the Site field and click Add.

Apple Safari

This information is based on Safari 11, released 2017-09-19. Apple Safari Version History

  1. See: Manage cookies and website data in Safari on Mac

Resources

RFC 6265: HTTP State Management Mechanism
http://tools.ietf.org/html/rfc6265
HTTP Cookies: Standards, Privacy, and Politics
arXiv:cs/0105018v1 [cs.SE]
How Internet Cookies Work
http://computer.howstuffworks.com/cookie.htm