HIPS:Human Interactive
Proofs
CAPTCHA: "Completely Automated Public Turing Test to Tell
Computers and Humans Apart"
Still Can get it,...Why these too are abbreviated...
While U are Logging in to this SITE, U entering a word from IMAGE....
Beside the Image u can see this word CAPTCHA.....If u r in still in Doubt Go and Relogin to this SITE Again.....
Why this is Used for.....U all want to Know...Lets Go in to Details..
CAPTCHAs based on technology created in part at Carnegie Mellon
University. However, Carnegie Mellon University does not decide how CAPTCHAs are
used by websites and email Services
CAPTCHAs are based on open problems in artificial intelligence (AI), they also offer
well-defined challenges for the AI community, and induce security researchers, as well as otherwise
malicious programmers, to advance the field of AI. (This is similar to research in cryptography
advancing algorithms for factoring large numbers.) Several groups have created programs that can pass
many CAPTCHAs over 80% of the time.
These algorithms represent significant progress in the area of
text
recognition.
CAPTCHAs are thus a win-win situation: either a CAPTCHA is not broken and there is a way
to differentiate humans from computers, or the CAPTCHA is broken and an AI problem is solved. Using
harder AI problems, our newly developed CAPTCHAs are still not broken.
CAPTCHA
TM tests
have several applications for
practical security, including (but not limited to)
Free Email Services.::
Several companies
(Yahoo!, Microsoft,
etc.) offer free email services. Most of these suffer from a specific
type of attack: "bots" that sign up for thousands of email accounts
every minute.
This situation can be improved by requiring users to prove they
are human before they can get a free email account. Yahoo!, for
instance, uses a CAPTCHA
TM test of our design
to
prevent bots from
registering for accounts.
Internet bot a type of computer program to do automated tasks
Search Engine Bots::
It is sometimes
desirable to
keep webpages
unindexed to prevent others from finding them easily
Worms and Spam::
.
CAPTCHA
TM
tests also offer
a plausible
solution against email worms and spam: "I will only accept an email if I
know there is a human behind the other computer." A few companies are
already marketing this idea.
Preventing Dictionary Attacks.
Pinkas and
Sander
have also suggested using CAPTCHA
TM tests to prevent
dictionary
attacks in password systems. The idea is simple: prevent a computer from
being able to iterate through the entire space of passwords.
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Thus far CAPTCHA we had discussed only visual ones what about Vissually impaired ......................
Yah I am coming there
is it !!!!!!!!!Audio CAPTCHA!!!!!!!!!!....
Absolutely! Audio CAPTCHAs
help visually impaired individuals navigate the Web easily.
Almost all the Details i had given...U want to Know More....
Take Mouse in to ur Hand Point to the URL Below...CLICK
www.captcha.net
Today when I am sending my mail to my friend from Yahoo...
I Noticed this....Afterwards I Noticed it in WWW.SURESHKUMAR.NET
Edited by: satyadev