validation code : Java Glossary

by Roedy Green ©1996-2009 Canadian Mind Products
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validation code

aka security code. A validation code is a combination vision test, typing test and ESP test you must take to prove yourself worthy of using some program, signing up for a forum, submitting a PAD, sending an EMAIL, or even getting on a junk mail list. The idea is it proves you are a real human, not some malicious automaton. You have to type the deliberately distorted letters and numbers you see such as:

validation code

Is that first one v911 or v9ll? or V911? Is the second 9EC15K or 9ECLSY?

The catch is you can’t tell o from O from 0 in isolation, or i from l from |, etc. I have complained to the creators of these torments and they ignore me. You have a similar but not so serious problem keying serial numbers and Windows activation codes. Any time you want people to key random gibberish, e.g. serial numbers, activation keys and validation codes, the number should not use the characters 0 o O 1 l. Alternatively, you can use the ambiguous letters but treat all similar-looking letters as equivalent. This does not reduce the psychological stress on the person typing however.

CAPTCHA

CAPTCHA is a nice-looking but inept commercial validation code software.

You will see the technique used on Blogger. Unfortunately, the creators of these tests usually require you to distinguish 1 from l and 0 from O from o without any meaningful contexts. So they waste the user’s time with ambiguous images. It usually takes me about 3 tries before I am able to type the code. Each time I am convinced I have it correct. It is a great way to infuriate your customers.

How To Cheat

If you are having trouble keying a validation code, use the Opera browser and crank the zoom up to 200%. Then if you still can’t figure out the pattern, hit reload, and you will get a different, hopefully easier test.

Recaptcha

A CAPTCHA has two parts, a bit of text from an old book that OCR could not read, and a random word digitally deformed and defaced. The server does not know the corresponding text for the first, but it does for the second. If you get the second part right, it presumes you know what you were doing for the first. This way as a side effect of solving the CAPTCHA, very old books (and the early editions of the New York Times) get converted to text.

PAD
Password

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