CAPTCHA: Telling Humans and Computers Apart Automatically

A CAPTCHA is a program that protects websites against bots by generating and grading tests that humans can pass but current computer programs cannot. This has the benefit of distinguishing humans from computers. It also creates incentive to further develop artificial intelligence of computers.

The term "CAPTCHA" was coined in 2000 by Luis Von Ahn, Manuel Blum, Nicholas J. Hopper, and John Langford (all of Carnegie Mellon University). It is a contrived acronym based on the word "capture" and standing for "Completely Automated Public Turing test to tell Computers and Humans Apart". Carnegie Mellon University attempted to trademark the term, but the trademark application was abandoned on 21 April 2008.

Applications

CAPTCHAs are used in attempts to prevent automated software from performing actions which degrade the quality of service of a given system, whether due to abuse or resource expenditure. CAPTCHAs can be deployed to protect systems vulnerable to e-mail spam, such as the webmail services of Gmail, Hotmail, and Yahoo Mail.

CAPTCHAs are also used to minimize automated posting to Blogs, forums and wikis. whether as a result of commercial promotion or harassment and vandalism. CAPTCHAs also serve an important function in rate limiting. Automated usage of a service might be desirable until such usage is done to excess and to the detriment of human users. In such cases, administrators can use CAPTCHA to enforce automated usage policies based on given thresholds.

As of 2010, most CAPTCHAs display distorted text that is difficult to read by character recognition software. The alternative implementations may include various tests, such as identifying an object that does not belong in a particular set of objects, locating the center of a distorted image, or identifying distorted shapes.

Accessibility

CAPTCHAs rely on visual perception, users unable to view a CAPTCHA due to a disability will be unable to perform the task protected by a CAPTCHA. Therefore, sites implementing CAPTCHAs may provide an audio version of the CAPTCHA in addition to the visual method. The official CAPTCHA site recommends providing an audio CAPTCHA for accessibility reasons, but it is not usable for deafblind people or for users of text web browsers. This combination is not universally adopted, with most websites (including Wikipedia) offering only the visual CAPTCHA, with or without providing the option of generating a new image if one is too difficult to read.

Use reCAPTCHA on Your Site

reCAPTCHA helps prevent automated abuse of your site (such as comment spam or bogus registrations) by using a CAPTCHA  to ensure that only humans perform certain actions.

• It's Free! Yep, reCAPTCHA is free.
• It's Useful. Why waste the effort of your users? reCAPTCHA helps to digitize books.
• It's Accessible. reCAPTCHA has an audio test that allows blind people to freely navigate your site.
• It's Secure. Most other CAPTCHA implementations can be easily broken.
• It's Popular. Over 100,000 sites use reCAPTCHA, including household names like Facebook, Ticketmaster, and Craigslist.
• It's Easy. reCAPTCHA is a Web service. As such, adopting it is as simple as adding a few lines of code on your site. For many applications and programming languages such as Wordpress and PHP we also have easy-to-install plugins available. We generate and check the distorted images, so you don't need to run costly image generation programs.

Captcha Fun: Guess Appropriate word from Pictures and write it in Answer Box.

http://server251.theory.cs.cmu.edu/cgi-bin/esp-pix/post-query-pix-esp

URL Shorteners, Banking Sites Increasingly Exploited by Online Crooks

McAfee also warns that URL shorteners, like those used to accommodate Twitter's140 character limit, make the cyber criminal's task even easier.

Unlike many typical Web addresses that show Internet users the name of the site they're about visit, shorter URLs tend to display a string of letters and numbers that seem to have no rhyme or reason. For example, instead of showing a user "http://bankofamerica.com"

abbreviated URLs might display only "http://bit.ly/XpEwA".

As another Internet security firm Symantec said in its recent report on 2010 threats, URL shortening services will "become the phisher's best friend."

"Because users often have no idea where a shortened URL is actually sending them, phishers are able to disguise links that the average security conscious user might think twice about clicking on," the company said.

As consumers continue to bank online, attacks on financial sites will likely increase in 2010...!!

After Success Of iPad1, Apple Inc. Ready Launching iPad2...!!!

The iPad is a line of tablet computers designed, developed and marketed by Apple primarily as a platform for audio-visual media including books, periodicals, movies, music, games, and web content. Its size and weight falls between those of contemporary smartphones and laptop computers. The iPad runs the same Operating System as the iPod Touch and iPhone and can run its own applications as well as iPhone applications. Without modifications and with the exception of web applications, it will only run programs approved by Apple and distributed via its online store.
Like iPhone and iPod Touch, the iPad is controlled by a multitouch display a departure from most previous tablet computers, which used a pressure-triggered stylus as well as a virtual onscreen keyboard in lieu of a physical keyboard. The iPad uses a Wi-Fi data connection to browse the Internet, load and stream media, and install software. Some models also have a 3G wireless data connection which can connect to HSPA (High Speed Packet Access) data networks. The device is managed and synced by iTunes on a personal computer via USB cable.
Apple released the first iPad in April 2010, and sold 3 million of the devices in 80 days. During 2010, Apple sold 14.8 million iPads worldwide, representing 75 percent of tablet PC sales at the end of 2010. During the release of the iPad2 in March 2011, Steve Jobs said that just under 15 million iPads had been sold in the device's first nine months on the market — more than all other tablet PCs combined.