What is CAPTCHA and How it Works?

CAPTCHA

CAPTCHA or Captcha (pronounced as cap-ch-uh) which stands for “Completely Automated Public Turing test to tell Computers and Humans Apart” is a type of challenge-response test to ensure that the response is only generated by humans and not by a computer. In simple words, CAPTCHA is the word verification test that you will come across the end of a sign-up form while signing up for Gmail or Yahoo account. The following image shows the typical samples of CAPTCHA.Almost every Internet user will have an experience of CAPTCHA in their daily Internet usage, but only a few are aware of what it is and why they are used. So in this post you will find a detailed information on how CAPTCHA works and why they are used.

What Purpose does CAPTCHA Exactly Serve?

CAPTCPA is mainly used to prevent automated software (bots) from performing actions on behalf of actual humans. For example while signing up for a new email account, you will come across a CAPTCHA at the end of the sign-up form so as to ensure that the form is filled out only by a legitimate human and not by any of the automated software or a computer bot. The main goal of CAPTCHA is to put forth a test which is simple and straight forward for any human to answer but for a computer, it is almost impossible to solve.

What is the Need to Create a Test that Can Tell Computers and Humans Apart?

For many the CAPTCHA may seem to be silly and annoying, but in fact it has the ability to protect systems from malicious attacks where people try to game the system. Attackers can make use of automated softwares to generate a huge quantity of requests thereby causing a high load on the target server which would degrade the quality of service of a given system, whether due to abuse or resource expenditure. This can affect millions of legitimate users and their requests. CAPTCHAs can be deployed to protect systems that are vulnerable to email spam, such as the services from Gmail, Yahoo and Hotmail.

Who Uses CAPTCHA?

CAPTCHAs are mainly used by websites that offer services like online polls and registration forms. For example, Web-based email services like Gmail, Yahoo and Hotmail offer free email accounts for their users. However upon each sign-up process, CAPTCHAs are used to prevent spammers from using a bot to generate hundreds of spam mail accounts.

Designing a CAPTCHA System

CAPTCHAs are designed on the fact that computers lack the ability that human beings have when it comes to processing visual data. It is more easily possible for humans to look at an image and pick out the patterns than a computer. This is because computers lack the real intelligence that humans have by default. CAPTCHAs are implemented by presenting users with an image which contains distorted or randomly stretched characters which only humans should be able to identify. Sometimes characters are striked out or presented with a noisy background to make it even more harder for computers to figure out the patterns.

Most, but not all, CAPTCHAs rely on a visual test. Some Websites implement a totally different CAPTCHA system to tell humans and computers apart. For example, a user is presented with 4 images in which 3 contains picture of animals and one contain a flower. The user is asked to select only those images which contain animals in them. This Turing test can easily be solved by any human, but almost impossible for a computer. 

Breaking the CAPTCHA

The challenge in breaking the CAPTCHA lies in real hard task of teaching a computer how to process information in a way similar to how humans think. Algorithms with artificial intelligence (AI) will have to be designed in order to make the computer think like humans when it comes to recognizing the patterns in images. However there is no universal algorithm that could pass through and break any CAPTCHA system and hence each CAPTCHA algorithm must have to be tackled individually. It might not work 100 percent of the time, but it can work often enough to be worthwhile to spammers.

How to access blocked Websites?

You might have experienced in some places that some websites wil be blocked for users to access.So if you want to know how to access those blocked websites ,here are some steps that might help your concern in unblocking those websites.

Steps:

STEP 1:

First try going to the blocked site with prefix https instead of http in the url.If the filtering mechanism is not too advanced this trick might work to access the blocked site.

STEP 2:

In case step 1 didnt solve your problem, in this case i suggest you to use an internet based proxy server to access the blocked sites. This way instead of using your browser to connect to the blocked site, first connect to any proxy server available on the internet and then through that proxy server you can go to the blocked websites to unblock it.These are some proxy servers….. “anonymizer.com“,”cooltunnel.com“,”bypassthat.com” etc and in these sites there will be an input box where you will need to type in the blocked site you want to visit (Blocked site) and you will be able to view your site.

STEP 3:

If that didnt work in case even these unblocking websites are blocked then, there is an other method to unblock it.In the internet there are many database websites that contain hundreds of proxy servers.An example is “Samair.ru” is a database that contains many proxy servers.

STEP 4: 

Now if all 3 steps didn’t work then,fear not. There is one more technique left.In this technique convert your website name into binary first. For this you will have to ping your site,this is done as Start->Run->type “cmd”->ok…Now type in “ping” followed by the blocked website eg:ping www.Google.com.This gives you the IP address of the blocked site.Now convert the octant(number between the decimals)into binary.This has to be done for each octant .Copy the resultant binary digits into the browser address bar.So even if the above STEPS 1 2 3 didn’t work,this will be able to unblock your website..Hope this was helpful:)..

Team Swastika group hacks 10,000 global Facebook account.

Security experts are warning web users to ensure they use strong passwords and vary their credentials from site to site after a new hacking group published log-in details of what it claimed to be more than 10,000 Facebook users.

Trend Micro's director of security research, Rik Ferguson, explained in a blog post that the "Team Swastika" group published the details to Pastebin "without context and with no indication of the means by which they were stolen".

Although the post has been removed by the data sharing service, Ferguson managed to take a screen grab of the stolen credentials.

He said that the account details come from all over the world, with the majority of users employing simple or easy-to-guess passwords.

"The ongoing effect of such a large-scale compromise can be disastrous for affected users, particularly if the password is shared for multiple accounts," Ferguson added.

"It can lead to compromise of the victim's email account which can act as the skeleton key for many other online services, as any password reset procedure will normally pass through the account owner's email inbox for verification. Regaining control of a compromised account can be a costly and time-consuming process."

Ferguson urged users to create a unique and complex password for every site they use, using upper and lower case letters, numbers and special characters.

"Devise a way to differentiate your password for each site you use, for example putting the first and last letters of the web site name at the beginning and end of your initial complex password, making it unique yet easy to remember," he said.

Ferguson also cautioned that security or password reset questions are only effective if the user is the only person who can answer the question.

For its part, Facebook was keen to stress it had not been the subject of a hack.

"This does not represent a hack of Facebook or anyone's Facebook profiles," said a spokesperson.

"Our security experts have reviewed this data and found it to be a set of
e-mail and password combinations that are not associated with any live
Facebook accounts."

Team Swastika has only just arrived on the hacking scene but the group has already published database tables and user credentials stolen from the Indian Embassy in Nepal and the Bhutan government, probably by SQL injection attack.

Ferguson told V3 he has contacted the group for more information but as yet its motivation and attack methodology remain unconfirmed.

FACEBOOK WILL END ON MARCH 15th, 2012!

PALO ALTO, CA –Mark Zuckerberg announced that Facebook will be shut down in March of 2012. Managing the site has become too stressful.

“Facebook has gotten out of control,” said Zuckerberg in a press conference outside his Palo Alto office, “and the stress of managing this company has ruined my life. I need to put an end to all the madness.”

Zuckerberg went on to explain that starting March 15th of next year, users will no longer be able to access their Facebook accounts.  That gives users (and Facebook addicts) a year to adjust to life without Facebook.

“After March 15th, 2012 the whole website shuts down,” said Avrat Humarthi, Vice President of Technical Affairs at Facebook. “So if you ever want to see your pictures again, I recommend you take them off the internet. You won’t be able to get them back after Facebook goes out of business.”

Zuckerberg said the decision to shut down Facebook was difficult, but that he does not think people will be upset.

“I personally don’t think it’s a big deal,” he said in a private phone interview. “And to be honest, I think it’s for the better. Without Facebook, people will have to go outside and make real friends. That’s always a good thing.”

Some Facebook users were furious upon hearing the shocking news.

“What am I going to do without Facebook?” said Denise Bradshaw, a high school student from Indiana. “My life revolves around it. I’m on Facebook at least 10 hours a day. Now what am I going to do with all that free time?”

However, parents across the country have been experiencing a long anticipated sense of relief.

“I’m glad the Facebook nightmare is over,” said Jon Guttari, a single parent from Detroit. “Now my teenager’s face won’t be glued to a computer screen all day. Maybe I can even have a conversation with her.”

SIGN THE “SAVE FACEBOOK” PETITION HERE

Those in the financial industry are criticizing Zuckerberg for walking away from a multibillion dollar franchise. Facebook is currently ranked as one of the wealthiest businesses in the world, with economists estimating its value at around 7.9 billion.

But Zuckerberg remains unruffled by these accusations. He said he will stand by his decision to give Facebook the axe.

“I don’t care about the money,” said Zuckerberg. “I just want my old life back.”

The Facebook Corporation suggests that users remove all of their personal information from the website before March 15th, 2012. After that date, all photos, notes, links, and videos will be permanently erased.

Most Useful Keyboard Shortcuts For Facebook

Facebook provides some useful keyboard shortcuts that could save you some extra time from reaching out to your mouse for all the clicks. Facebook shortcuts not only help you save some time of your regular facebook usage but can also help you navigate your favorite social network easily :D. So is a list of useful keyboard shortcuts that could really help you save some time.

Google Chrome

 [

• Alt+M Send new message, Opens up facebook new message box
• Alt+/ Move Cursor to Search Box
• Alt+1 View Home Page(News Feed)
• Alt+2 View Profile Page
• Alt+3 Accept or Decline Friend Requests
• Alt+4 Open Message Page
• Alt+5 Open Notification Bar
• Alt+6 View Account Settings
• Alt+7 View Privacy Settings
• Alt+8 View Facebook Fan Page
• Alt+9 Read the Facebook Terms of Service Agreement

Firefox

• Shift+Alt+M Send new message, Opens up Facebook new message box
• Shift+Alt+/ Move Cursor to Search Box
• Shift+Alt+1 View Home Page(News Feed)
• Shift+Alt+2 View Profile Page
• Shift+Alt+3 Accept or Decline Friend Requests
• Shift+Alt+4 Open Message Page
• Shift+Alt+5 Open Notification Bar
• Shift+Alt+6 View Account Settings
• Shift+Alt+7 View Privacy Settings
• Shift+Alt+8 View Facebook Fan Page
• Shift+Alt+9 Read the Facebook Terms of Service Agreement

Well there are your time saving shortcuts for you to try out. If you know any other Facebook shortcuts ,lets us know by sharing with us by your comments…….

Tribute to Steve Jobs

Thank you so much Steve for giving such a wonderful gifts to this World. You only invented the products for the construction of wonderful world unlike the products for the destruction. Your product, iPhone, is the gift that will always be with me…you will always be remembered in the history of mankind and civilization. RIP…you will surely have a heavenly adobe . May his soul rest in peace from ITSANCHAR  Family.