Re: [PanoToolsNG] Evercookies -- something I didn't know about that seems important to me...
- For even more, you might look at <http://samy.pl/evercookie/>
persistent cookies in a browser. Its goal is to identify a client
even after they've removed standard cookies, Flash cookies (Local
Shared Objects or LSOs), and others. evercookie accomplishes this by
storing the cookie data in several types of storage mechanisms that
are available on the local browser. Additionally, if evercookie has
found the user has removed any of the types of cookies in question, it
recreates them using each mechanism available."
I'm particularly impressed with "Storing cookies in RGB values of auto-
generated, force-cached PNGs using HTML5 Canvas tag to read pixels
(cookies) back out" (!) ... just in case you hadn't thought of
(yikes!) THAT trick.
On Feb 11, 2011, at 8:31 AM, Ken Warner wrote:
> cookies in a web browser that are
> intentionally difficult to delete.
> A traditional HTTP cookie is a relatively small amount of textual
> data that is stored by the user's
> browser. Cookies can be used to save preferences and login session
> information; however, they can
> also be employed to track users for marketing purposes. Due to
> concerns over privacy, all major
> browsers include mechanisms for deleting and/or refusing to accept
> cookies from websites.
> The size restrictions, likelihood of eventual deletion, and simple
> textual nature of traditional
> cookies motivated Adobe Systems to add the Local Shared Object (LSO)
> mechanism to the Adobe Flash
> player. . While Adobe has published a mechanism for deleting LSO
> cookies (which can store 100KB
> of data per website, by default), it has met with some criticism
> from security and privacy
> experts. In response to the relative difficulty of removing LSO
> cookies, browser add-ons such as
> Firefox's "Better Privacy" plugin have been developed. As of
> 2010-10-23, the "Better Privacy"
> plugin has been downloaded roughly 3.5 million times.
> Evercookie is not merely difficult to delete, it actively "resists"
> deletion by redundantly copying
> itself in different forms on the user's machine, and resurrecting
> itself if it notices some of the
> copies are missing or expired. As such, it serves to highlight the
> ways in which creators of malware
> can attack browsers.
> Firefox has a plugin that will remove evercookies -- *I had 11 of
> them on my computer!!!*
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