The registration code required for registering on some sites

[gromehown]

On some forums when you sign up you have to enter some generated letters and numbers. Why do they always have to be so difficult to read? Weird psychedelic fonts and color schemes abound... why?

[Joey P]

Originally Posted by gromehown

On some forums when you sign up you have to enter some generated letters and numbers. Why do they always have to be so difficult to read? Weird psychedelic fonts and color schemes abound... why?

It makes sure that computers can't enter the code by 'reading' the letters. You'll see it alot on sites where people would like to automate things, for example, ticketmaster or a backround info type site. Now let's see if I can find the acronym before someone else gets in here.

[Joey P]

CAPTCHA

[Nanoda]

KittenAuth (V2)

[Shagnasty]

The above is correct. However, it is helpful to break the explanation into how computers read things and how humans do. Computers use codes for letters. On top of these may be fonts and sizes to display the results to make it nice for humans but computers still know what is under the hood and still have no problem interpreting letters from just about anything.

However, you can also have pictures of letters like a photo of a sign and computers can have some serious but not insurmountable problems with those. Optical Character Recognition (OCR) software can still try and make sense of the letters and words displayed in pictures using ever improving algorithms.

The one thing that humans are almost infinitely better at than computers is complex pattern matching. Humans can recognize patterns like faces almost instantly while computers generally have a huge problem with that type of thing. Obscured text with letters for a human user to enter can beat computers that are trying to login to web sites for other purposes.

[Rysto]

And the reason that they don't want computers to be able to sign up accounts is to prevent spammers from making thousands of accounts and floading the forums with advertisements.

[gromehown]

Wow, what a simple and obvious answer. Thanks!