Google +1 tracks mouse movements?

http://stackoverflow.com/questions/6667544/why-does-google-1-record-my-mouse-movements

by Gullanian • 15 years ago

97 26 15 years ago

stackoverflow.com

sundae79• 15 years ago

Does the emperor wear any clothes?

tectonic• 15 years ago

According to the link, this is being used as a source of entropy to generate random numbers. Fascinating.

palish• 15 years ago

Hah!

That's so simple, yet so brilliant.

obtino• 15 years ago

Mouse movements have been long used as a source of entropy in desktop applications.

willscott• 15 years ago

Seems pretty reasonable to expect it to be this code from the apache shindig library:

http://svn.apache.org/repos/asf/shindig/trunk/features/src/m...

From the file: This code implements a safer random() method that is seeded from screen width/height and (presumably random/unguessable) mouse movement, in an effort to create a better seed for random().

Its aim is to solve the problem of gadgets that are relying on secret RPC tokens to validate identity.

sebkomianos• 15 years ago

Aren't there a lot of patterns on how we interact with an interface?

For example, most people on facebook move their pointers to check their notifications/new messages/friend requests. Wouldn't that produce a lot of "not so random" random numbers?

(I am not looking to start a conversation on how random random numbers are, just curious on why they used this specific technique)

Palomides• 15 years ago

cute, but surely there are less intensive ways of generating random numbers?

glimcat3• 15 years ago

I've always been a fan of using electronic noise. It's not complicated to build a device which does this. Weekend project to "hello world" scale if you're not too picky about specifics.

Easiest way is probably with a webcam, which will also give you a pretty good bitrate. The general schema is to read out the bias noise. You do this by blocking out any incoming light to get dark noise + bias noise. Dark noise is an assumed static shift due to CCD characteristics, so read N frames of this and look for the median signal. Subtract that off and you've got the bias, or at least something that's close enough for a weekend project.

Better version, start reading up on the math of noise sources in whatever device you want to use for a sensor. Also do an analysis of N samples to see how close the result comes to the expectation value given the type of noise involved and what deviation is expected at N samples.

baddox• 15 years ago

There's no way to deploy this over the web, unless you use Flash to acquire their webcam video or audio.

andrewcooke• 15 years ago

obsessive correction of small, largely irrelevant detail (while upvoting in general agreement): what you subtract (the constant shift, which actually does have some structure) is the bias. what you're left with is the dark noise.

you could also point the camera at a flat white surface - that would give you a lot more noise (so much you probably don't need to worry about subtracting anything, if you just take the least significant bits from each pixel)

[i hope i'm right - i wrote astronomy image reducing software for a living]

brianshumate• 15 years ago

Seems like overall, it's definitely code to help thwart gaming of the +1 system, as there is already a cottage industry that offers (presumably) automated +1 clicking services for money.

anon543• 15 years ago

Google Analytics does it too, which makes approx. 85% of all web sites you visit.

zobzu• 15 years ago

adblock'd sites dont do it :)

victoriussecret• 15 years ago

I'm not sure how often research papers reflect reality, but Bing may be doing this as well, according to this Microsoft Research paper: http://jeffhuang.com/Final_CursorBehavior_CHI11.pdf

antics• 15 years ago

This is a very good paper, but it seems to approach mouse tracking specifically from the search perspective. Perhaps not extremely pertinent, but still super interesting.

known• 15 years ago

http://www.ghostery.com/ prevents it

Google +1 tracks mouse movements?

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