WEB 2.0

                        The term Web 2.0 is commonly associated with web applications that facilitate interactive information sharing, interoperability, user-centered design, and collaboration on the World Wide Web. A Web 2.0 site gives its users the free choice to interact or collaborate with each other in a social media dialogue as creators (prosumer) of user-generated content in a virtual community, in contrast to websites where users (consumer) are limited to the passive viewing of content that was created for them. Examples of Web 2.0 include social-networking sites, blogs, wikis, video-sharing sites, hosted services and  web-applications.

   Whether Web 2.0 is qualitatively different from prior web technologies has been challenged by World Wide Web inventor Tim Berners-Lee, who called the term a "piece of jargon", precisely because he intended the Web in his vision as "a collaborative medium, a place where we [could] all meet and read and write". He called it the 'Read/Write Web'.

Characteristics:

    Web 2.0 websites allow users to do more than just retrieve information. By increasing what was already possible in "Web 1.0", they provide the user with more user-interface, software and storage facilities, all through their browser. This has been called "Network as platform" computing. Users can provide the data that is on a Web 2.0 site and exercise some control over that data. These sites may have an "Architecture of participation" that encourages users to add value to the application as they use it.

Some of the most popular examples are:

• Gmail
• Google Maps
• Flickr
• Orkut
• Windows Live
• Facebook

What is Cloud Computing?

Cloud computing is an emerging computing technology that uses the internet and central remote servers to maintain data and applications. Cloud computing allows consumers and businesses to use applications without installation and access their personal files at any computer with internet access. This technology allows for much more efficient computing by centralizing storage, memory, processing and bandwidth,In general..


* The cloud is a group of servers.
* A user interacts with the cloud without worrying about how it is implemented.
* The cloud company does all the magic

We use the cloud daily.
* Google
* Facebook
* Windows Live

Cloud computing comes into focus only when you think about what IT always needs: a way to increase capacity or add capabilities on the fly without investing in new infrastructure, training new personnel, or licensing new software. Cloud computing encompasses any subscription-based or pay-per-use service that, in real time over the Internet, extends IT's existing capabilities.

In general, cloud computing customers do not own the physical infrastructure, instead avoiding capital expenditure by renting usage from a third-party provider. They consume resources as a service and pay only for resources that they use. Many cloud-computing offerings employ the utility computing model, which is analogous to how traditional utility services (such as electricity) are consumed, whereas others bill on a subscription basis. Sharing "perishable and intangible" computing power among multiple tenants can improve utilization rates, as servers are not unnecessarily left idle (which can reduce costs significantly while increasing the speed of application development)


2 types of clouds:

* SaaS- Software as a service. Software that exists on the cloud. For example, Google documents allows users to create, edit, and share spreadsheets, text documents, and presentations similar to powerpoint. Or, Facebook. All of which is stored on the cloud.

* HaaS- Hardware as a service. Allows anyone to purchase space on a cloud in which they can place applications, games, and almost any software that usually sits on one’s desktop. Now, those applications will run in the cloud instead of taking up space on your computer. Examples: Amazon ec2, SaleForce.com

INTERESTING FACTS ABOUT GOOGLE

GOOGLE Inc is a multinational public cloud computing, Internet search, and advertising technologies corporation.

Google hosts and develops a number of Internet-based services and products,and generates profit primarily from advertising through its AdWords program.

The company was founded by Larry Page and Sergey Brin, often dubbed the "Google Guys", while the two were attending Stanford University as Ph.D. candidates.

It was first incorporated as a privately held company on September 4, 1998.

The company's stated mission from the outset was "to organize the world's information and make it universally accessible and useful".

Google runs over one million servers in data centers around the world, and processes over one billion search requests and twenty petabytes of user-generated data every day.

Ninety-nine percent of Google's revenue is derived from its advertising programs.

Google's original homepage had a simple design since its founders were not experienced in HTML, the language for designing web pages.

History:

Google began in January 1996 as a research project by Larry Page and Sergey Brin when they were both PhD students at Stanford University in California.While conventional search engines ranked results by counting how many times the search terms appeared on the page, the two theorized about a better system that analyzed the relationships between websites. They called this new technology PageRank, where a website's relevance was determined by the number of pages, and the importance of those pages, that linked back to the original site.

The name to Google, originating from a misspelling of the word "googol", the number one followed by one hundred zeros, which was meant to signify the amount of information the search engine was to handle.

The first funding for Google was on August 1998 contribution of US$100,000 from Andy Bechtolsheim, co-founder of Sun Microsystems.

Brin and Page decided that the search engine they had developed was taking up too much of their time from academic pursuits. They went to Excite CEO George Bell and offered to sell it to him for $1 million.But he rejected the offer.

Will BlackBerry face a ban in India?

That's the big question in the minds of over 10 lakh (1 million) BlackBerry users in India. The government has now warned that it would block 'BlackBerry-to-BlackBerry messenger' service if the maker of BlackBerry -- Research In Motion(RIM) -- does not offer a solution to monitor messages within a week.
                                        
                                          The Indian government had raised security concerns over BlackBerry messages since 2008. However, BlackBerry still continues its services without complying to Indian security regulations.
While the Indian government wants BlackBerry to allow monitoring of e-mails and SMS, RIM has said the security architecture for its enterprise customers is based on a symmetric key system whereby the customers create their own key and only they possess the copy of the encryption.


BlackBerry's justification

BlackBerry says the messages are encrypted. The smartphone's server is based in Canada where the encryption level is very high and extremely difficult to crack.
And any message going through a Canada server is encrypted and, therefore, cannot be accessed by intelligence agencies in India.

"RIM does not possess a master key nor does any back door exists in the system that would allow RIM or any third party to gain an unauthorised access to the key or corporate data," the company said.

It, therefore, would be unable to accommodate any request for a copy of a customer's encryption key since at no time does RIM, or any wireless network operator, ever possess a copy of the key.


The latest development indicates that security agencies are again finding it difficult to intercept or decipher messages sent through these phones, which use codes with an encryption of 256 bits.

This encryption code first scrambles the emails sent from a BlackBerry device and unscrambles them when the message reaches its target.


 

What is meant by RSS Feed?

What is RSS? The term RSS is refers to "Really Simple Syndication", in general, sometimes used to refer to web feeds, an RSS document is called a "web feed or channel" includes full or summarized text, plus metadata such as publishing dates and authorship. This is where the reader can easily subscribe to get their favorite websites with interesting topics and updated contents on it and aggregate feeds from many sites into one place.

                  An RSS feed consists of software called RSS reader, feed reader, or aggregator which can be web-based or desktop-based. The users can subscribe to a feed by having feed's URL from a certain website into the reader or by clicking an RSS icon in a browser that initiates the subscription process. The RSS reader simply checks the user's subscribed feeds regularly for new work or post and read the feeds.

HIDE YOUR FILES IN A JPEG FILE

For this, you will only need to download WinRAR, and you just need to have a little knowledge about Command Prompt and have WinRAR installed. Ok, lets begin…

 1. Gather all the files that you wish to hide in a folder anywhere in your PC (make it in C:\hidden                   –                   RECOMMENDED).
 2. Now, add those files in a RAR archive (e.g. secret.rar). This file should also be in the same directory (C:\hidden).
 3. Now, look for a simple JPEG picture file (e.g. logo.jpg). Copy/Paste that file also in C:\hidden.
4. Now, open Command Prompt (Go to Run and type ‘cmd‘). Make your working directory C:\hidden.
5. Now type: “COPY /b logo.jpg + secret.rar output.jpg” (without quotes) – Now, logo.jpg is the picture you want to show, secret.rar is the file to be hidden, and output.jpg is the file which contains both.
   6. Now, after you have done this, you will see a file output.jpg in C:\hidden. Open it (double-click) and it will show the picture you wanted to show. Now try opening the same file with WinRAR, it will show the hidden archive… This hack will allow you to hide files in jpegs’s without software installed.

KNOW THE IP ADDRESS OF A WEBSITE

As i have said in earlier posts that every website have an unique IP address and it is named only for our convenience.Sometimes you want to know the IP address of a particular site to hack or to do something else.To satisfy your needs i tell the way to find the IP of a site from windows connected to internet.For example when you want to know the IP of google.com then goto run and type "cmd" the command prompt will open here type the following command.

ping google.com

and press ENTER.

Now you will see the a number of lines indicating the status of connection including the IP address of the site.You cam find the IP of any site by using this method when you are currently connected to the internet.

DNS ADDRESS

DNS stands for Domain Name Server.The domain of each website has an ip address.As it is difficult remember the ip addresses each ip address is assigned a domain name.When we enter the url of our website in the browser the DNS will convert it into corresponding ip address then the page is loaded.You can also simply type the ip address of the website instead of the url.

DIFFERENCE BETWEEN BLOG AND WEBSITE

Though the blog and website are seem to be same there are many important differences between them.The main difference that differentiate the two is STATIC PAGES.The blog doesnt contain any static pages because it was initially invented to share the personal ideas of a person with his friends and relatives which is updated frequently.Also the blog doesnt contain the storage space and as a result it should provide external link for downloading of files.On the other hand websites contain static pages and also the storage space.The search engines will give high priority for blog compare to website as it is updated frequently.As a result the commercial organisation will employ both blog with a link to its website for better results.

GOOGLE Search Techniques and Query Optimization

Google supports several syntax and optimisation for the queries by which the user can get the desired output.I summarize some important features.


1.There are certain circumstances when you require result from only a certain site excluding result from another sites.At that time try the following format using (site:) command.
For ex[site:rajamanikanta.blogspot.com search]

Try the above query without the brackets and see the result.


2.Another important feature provided by google is built in calculator which performs mathematic operations.Try the following queries.


1+100
2*5

3.When you want to know the meaning of certain word then try the following query.
ex.[define word]
Use the above query by replacing the word with word you want to know the meaning without the bracket.


4.When you want to know the time of a certain city then use the following query.

ex.[time Chennai]

5.Google provides inbuilt unit conversion from one unit to another by simply providing a query in the following format.

ex. [60kg to gram]

Google supports many types of such a conversion from one unit to another.


Apart from this it provides many services especially for U.S such as fligt status etc.

WINDOWS-BATCH FILE

Windows batch file is nothing but a line by line collection of commands that are executed in command prompt.To create a batch file open the notepad and type the commands line by line and save as of type .bat.For example consider the following example
cd c:\\images
del a.gif
and save the file as example.bat.
When you double click the above created batch file a.gif in the images folder is deleted.

STEGANOGRAPHY

Steganography is defined as the art of hidden way of writing whereas the cryptography is the secret way of writing.By using cryptography the third person will know something is crypted.The major advantage of Steganography over cryptography is that it is almost impossible to know that something is hidden.We know that every image is made up of several bits.The data to be hidden is also a series of bits. Steganography replaces the least visible bits in the image by the data bits which is unidentified by the human eyes.The bits to be replaced is generated by an algorithm shared by sender and receiver.The receiver user the same algorithm to generate the bits where his message is hidden.The message is usually compressed and then encrypted before hiding inside a image.As the terrorists extensively use this method for conspiracy the government has involved in extensive research in this field to counteract the terrorists.

Revealing Wikipedia

Most of the student and teaching community will opt for Wikipedia as the primary source of information.But most of us dont know many amazing facts about this fabulous site.The articles in this site are created and edited by billions of contributor like us around the world.
Due to the above fact it suffers from vandalism(i.e some persons will utilize it for publishing their ads and make a link to anonymous site)and some of its articles contain fake and unverified information.Therefore some persons will not accept the references from Wikipedia.

Despite of criticism and controversies by many experts around the world some of its features marked it apart.
1)Wikipedia is the fifth most viewed website in the world.This may be due to google which gives highest priority to Wikipedia in its search results.
2)It is non commercial which doesnt support ads of any kind in its pages.A survey discovered that when this site supports ads it will earn many billions per year.It will ask for voluntary donation once in a year for its expenses.
3)It is available in more than 200 languages and contains more than billion articles on almost every topic and it is ever increasing.
Last but not least it employs less than 35 persons for maintaining such a large site.
Wikipedia has taken many steps to ensure the reliability of its contents which includes the inclusion of talk page and history page for contributors which is capable of rollback to previous states when it is damaged by vandals.

Hi Friends...

This blog is especially designed to share  knowledge regarding Computer science technologies,
 and  I welcome all u guys to share ur valuable intelligence ... 

NEED FOR CAPTCHA

When you creating an account in any website you are prompted to enter the words given in the picture in the box as it is.This is called captcha.It is necessary because some software will create numerous number of account which the account providers doesnt like therefore they provide captcha which will not be identified by the software.In gmail when you enter the wrong password for five times it will request to fill the captcha this is because there are softwares that will try all the combination of words and numbers to hack the account.

TYPES OF CRYPTOGRAPHY

Cryptography is defined as the secret way of writing.It involves three steps such as encryption,transmission,decryption.The cryptographic process involves an element called key for encryption and decryption.The key is like a password for a folder. It is primarily divided into three different types.They are
1.Symmetric encryption
2.Asymmetric encryption
3.Hybrid encryption
SYMMETRIC ENCRYPTION
In this method the same key is used for both encryption and decryption.By doing so the key should be transmitted from sender to receiver through the network,which is easy for the hackers to obtain the key and decrypt it.This method is very faster because same key is used for both encryption and decryption but is very insecure.This method is on longer in use.


ASYMMETRIC ENCRYPTION
This is a very effective method since the receives will generate a pair of keys(private key and public key).He sends the public key to the sender from whom he wish to receive the data,hacking of this key will not effect because it will only be able to encrypt the data.The sender encrypt the data with public key and transmit over the lines to the receiver.Upon receiving the data the receiver decrypt the message with his private key.The two keys are designed in such a way that the private key will not be derived from public key with the algorithms such as RSA algorithm.This type of encryption is like a padlock where anyone can easily lock(encrypt) just by pressing but the key is required for opening(decrypt).The main disadvantage of this type is that it is atleast 1000 times slower than symmetric method.

HYBRID ENCRYPTION
This method combines the advantages of the above two methods.In this method the data is symmetrically encrypted and the symmetric key is asymmetrically encrypted with the public key of receiver.At the receiver end with the help of his private key the symmetric key is taken out and that key is used to decrypt the data.This method is as fast as symmetric method because here only the key is asymmetrically encrypted which is very small in size and also this method has the security features available in asymmetric method.