Presentation ReportTopic:-

Department:-CS&IT

Class:-SE-I (2011-2015)

Submitted to:-Sir. Aftab Naseem.

Subject:-Programming

Group Members

Name Roll #1. Bilal Maqbool. 10 (Internet Introduction & History)2. Abdul Ghafar. 14

(Communication & working of Internet)3. Nisar Ahmed. 06 (Security of Internet)4. Shahzad Tanvir. 21

(Advantages & Disadvantages of Internet)5. Muhammad Junaid. 45 (Future of Internet)

IntroductionBy the turn of the century, information, including access to the Internet, will be the basis for personal, economic, and political advancement. The popular name for the Internet is the information superhighway. Whether you want to find the latest financial news, browse through library catalogs, exchange information with colleagues, or join in a lively political debate, the Internet is the tool that will take you beyond telephones, faxes, and isolated computers to a burgeoning networked information frontier. The Internet supplements the traditional tools you use to gather information, Data Graphics, News and correspond with other people. Used skillfully, the Internet shrinks the world and brings information, expertise, and knowledge on nearly every subject imaginable straight to your computer. 

What is the Internet?The Internet links are computer networks all over the world so that users can share resources and communicate with each other. Some computers have direct access to all the facilities on the Internet such as the universities. And other computers, eg privately-owned ones, have indirect links through a commercial service provider, who offers some or all of the Internet facilities. In order to be connected to Internet, you must go through service suppliers. Many options are offered with monthly rates. Depending on the option chosen, access time may vary. The Internet is what we call a metanetwork, that is, a network of networks that spans the globe. It's impossible to give an exact count of the number of networks or users that comprise the Internet, but it is easily in the thousands and millions respectively. The Internet employs a set of standardized protocols which allow for the sharing of resources among different kinds of computers that communicate with each other on the network. These standards, sometimes referred to as the Internet Protocol Suite, are the rules that developers adhere to when creating new functions for the Internet. The Internet is also what we call a distributed system; there is no central archives. Technically, no one runs the Internet. Rather, the Internet is made up of thousands of smaller networks. The Internet thrives and develops as its many users find new ways to create, display and retrieve the information that constitutes the Internet. 

Who Pays for the Internet?There is no clear answer to this question because the Internet is not one "thing", its many things. No one central agency exists that charges individual Internet users. Rather, individuals and institutions who use the Internet pay a local or regional Internet service provider for their share of services. And in turn, those smaller Internet service providers might purchase services from an even larger network. So basically, everyone who uses the Internet in some way pays for part of it. 

Electronic mail on the internet:Electronic mail, or e-mail, is probably the most popular and widely used Internet function. E-mail, email, or just mail, is a fast and efficient way to communicate with friends or colleagues. You can communicate with one person at a time or thousands; you can receive and send files and other information. You can even subscribe to electronic journals and newsletters. You can send an e-mail message to a person in the same building or on the other side of the world.

DomainsThe right-most segment of domain names usually adhere to the naming conventions listed below:  EDU   Educational sites in the United States COM Commercial sites in the United States GOV Government sites in the United States NET   Network administrative organizations MIL    Military sites in the United States ORG Organizations in the U.S. not covered by the categories above (e.g., non-profit organizations)..xx      where xx is the country code (e.g., .eg for Egypt).

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Introduction to Gopher:Gopher is a client/server system that allows you to access many Internet resources simply by making selections from a sequence of menus. Each time you make a selection, Gopher carries out your request to the computer that contains the information and "serves" it up. For example, if you select a menu item that represents a text file, Gopher will get that file--wherever it happens to be--and display it for you. As you use Gopher, some menu items lead to other menus. If you choose one of these, Gopher will retrieve the new menu and display it for you. Thus you can move from menu to menu, using only a few key strokes or a mouse to navigate. The power of Gopher is that the resources listed in a menu may be anywhere on the Internet. As Gopher connects to computers to comply with your menu selection, you don't need to be preoccupied with the behind-the-scenes work of connecting to and disconnecting from these various computers. Gopher does this for you without your even needing to be aware of it. This automatic connecting makes Gopher popular and useful. 

Where did Gopher come from?"Born" in April 1991, gopher began as a project at the Microcomputer, Workstation, and Networks Center at the University of Minnesota to help people on campus get answers to computer-related questions. At the time, the computer center staff had accumulated answers to thousands of questions regarding computers and software.What was needed was an easy and efficient way to deliver this information to students, faculty and staff. Thus, the creation of Gopher reaffirms the adage that necessity is the mother of invention. 

Why is it called Gopher?The name "Gopher" is appropriate for three reasons:    1.Just as a real gopher successfully navigates beneath the prairie, the Internet Gopher tunnels through the invisible paths of the Internet to help you find the information you want.    2. The name refers to someone who fetches things or provides service for other people.    3. The Golden Gopher is the mascot of the University of Minnesota. 

A look at search engines:

The World Wide Web is "indexed" through the use of search engines, which are also referred to as "spiders," "robots," "crawlers," or "worms". These search engines comb through the Web

documents, identifying text that is the basis for keyword searching. Each search engine works in a different way. Some engines scan for information in the title or header of the document; others

look at the bold "headings" on the page for their information. The fact that search engines gather information differently means that each will probably yield different results. Therefore, it's wise to

try more than one search engine when doing Web searching.The list below lists several search engines and how each one gathers information, plus resources that evaluate the search engines. Finally the internet is a huge source of information in all fields of knowledge. Datum will take your hand through this incredible world of information to get what you need in a fast, reliable and professional way. 

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History Of InternetThe Internet was the result of some visionary thinking by people in the early 1960s who saw great potential value in allowing computers to share information on research and development in scientific and military fields. J.C.R. Licklider of MIT, first proposed a global network of computers in 1962, and moved over to the Defense Advanced Research Projects Agency (DARPA) in late 1962 to head the work to develop it. Leonard Kleinrock of MIT and later UCLA developed the theory of packet switching, which was to form the basis of Internet connections. Lawrence Roberts of MIT connected a Massachusetts computer with a California computer in 1965 over dial-up telephone lines. It showed the feasibility of wide area networking, but also showed that the telephone line's circuit switching was inadequate. Kleinrock's packet switching theory was confirmed. Roberts moved over to DARPA in 1966 and developed his plan for ARPANET. These visionaries and many more left unnamed here are the real founders of the Internet.The Internet, then known as ARPANET, was brought online in 1969 under a contract let by the renamed Advanced Research Projects Agency (ARPA) which initially connected four major computers at universities in the southwestern US (UCLA, Stanford Research Institute, UCSB, and the University of Utah). The contract was online in December 1969.

Who was the first to use the Internet?Charley Kline at UCLA sent the first packets on ARPAnet as he tried to connect to Stanford Research Institute on Oct 29, 1969. The system crashed as he reached the G in LOGIN! The early Internet was used by computer experts, engineers, scientists, and librarians. There was nothing friendly about it. There were no home or office personal computers in those days, and anyone who used it, whether a computer professional or an engineer or scientist or librarian, had to learn to use a very complex system.

Did Al Gore invent the Internet?According to a CNN transcript of an interview with Wolf Blitzer, Al Gore said,"During my service in the United States Congress, I took the initiative in creating the Internet." Al Gore was not yet in Congress in 1969 when ARPANET started or in 1974 when the term Internet first came into use. Gore was elected to Congress in 1976. In fairness, Bob Kahn and Vint Cerf acknowledge in a paper titled Al Gore and the Internet that Gore has probably done more than any other elected official to support the growth and development of the Internet from the 1970's to the present.

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What makes the internet work?

The unique thing about the Internet is that it allows many different computers to connect and talk to each other. This is possible because of a set of standards, known as protocols, that govern the transmission of data over the network: TCP/IP (Transmission Control Protocol/Internet Protocol). Most people who use the Internet aren't so interested in details related to these protocols. They do, however, want to know what they can do on the Internet and how to do it effectively.  Internet AddressesBecause the Internet is a global network of computers each computer connected to the Internet must have a unique address. Internet addresses are in the form nnn.nnn.nnn.nnn where nnn must be a number from 0 - 255. This address is known as an IP address. (IP stands for Internet Protocol; more on this later.) The picture below illustrates two computers connected to the Internet; your computer with IP address 1.2.3.4 and another computer with IP address 5.6.7.8. The Internet is represented as an abstract object in-between. (As this paper progresses, the Internet portion of Diagram 1 will be explained and redrawn several times as the details of the Internet are exposed.)

If you connect to the Internet through an Internet Service Provider (ISP), you are usually assigned a temporary IP address for the duration of your dial-in session. If you connect to the Internet from a local area network (LAN) your computer might have a permanent IP address or it might obtain a temporary one from a DHCP (Dynamic Host Configuration Protocol) server. In any case, if you are connected to the Internet, your computer has a unique IP address.

Protocol Stacks and PacketsSo your computer is connected to the Internet and has a unique address. How does it 'talk' to other computers connected to the Internet? An example should serve here: Let's say your IP address is 1.2.3.4 and you want to send a message to the computer 5.6.7.8. The message you want to send is "Hello computer 5.6.7.8!". Obviously, the message must be transmitted over whatever kind of wire connects your computer to the Internet. Let's say you've dialed into your ISP from home and the message must be transmitted over the phone line. Therefore the message must be translated from alphabetic text into electronic signals, transmitted over the Internet, and then translated back into alphabetic text. How is this accomplished? Through the use of a protocol stack. Every computer needs one to communicate on the Internet and it is usually built into the computer's operating system (i.e. Windows, Unix, etc.). The protocol stack used on the Internet is referred to as the TCP/IP protocol stack because of the two major communication protocols used. The TCP/IP stack looks like this:

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Protocol Layer Comments 1

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Application Protocols Layer Protocols specific to applications such as WWW, e-mail, FTP, etc.

Transmission Control Protocol Layer

TCP directs packets to a specific application on a computer using a port number.

Internet Protocol Layer IP directs packets to a specific computer using an IP address.

Hardware Layer Converts binary packet data to network signals and back.(E.g. Ethernet network card, modem for phone lines, etc.)

If we were to follow the path that the message "Hello computer 5.6.7.8!" took from our computer to the computer with IP address 5.6.7.8, it would happen something like this:

1. The message would start at the top of the protocol stack on your computer and work its way downward.

2. If the message to be sent is long, each stack layer that the message passes through may break the message up into smaller chunks of data. This is because data sent over the Internet (and most computer networks) are sent in manageable chunks. On the Internet, these chunks of data are known as packets.

3. The packets would go through the Application Layer and continue to the TCP layer. Each packet is assigned a port number. Ports will be explained later, but suffice to say that many programs may be using the TCP/IP stack and sending messages. We need to know which program on the destination computer needs to receive the message because it will be listening on a specific port.

4. After going through the TCP layer, the packets proceed to the IP layer. This is where each packet receives its destination address, 5.6.7.8.

5. Now that our message packets have a port number and an IP address, they are ready to be sent over the Internet. The hardware layer takes care of turning our packets containing the alphabetic text of our message into electronic signals and transmitting them over the phone line.

6. On the other end of the phone line your ISP has a direct connection to the Internet. The ISPs router examines the destination address in each packet and determines where to send it. Often, the packet's next stop is another router. More on routers and Internet infrastructure later.

7. Eventually, the packets reach computer 5.6.7.8. Here, the packets start at the bottom of the destination computer's TCP/IP stack and work upwards.

8. As the packets go upwards through the stack, all routing data that the sending computer's stack added (such as IP address and port number) is stripped from the packets.

9. When the data reaches the top of the stack, the packets have been re-assembled into their original form, "Hello computer 5.6.7.8!"

Domain Names and Address ResolutionBut what if you don't know the IP address of the computer you want to connect to? What if the you need to access a web server referred to as www.anothercomputer.com? How does your web browser know where on the Internet this computer lives? The answer to all these questions is the

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Domain Name Service or DNS. The DNS is a distributed database which keeps track of computer's names and their corresponding IP addresses on the Internet. Many computers connected to the Internet host part of the DNS database and the software that allows others to access it. These computers are known as DNS servers. No DNS server contains the entire database; they only contain a subset of it. If a DNS server does not contain the domain name requested by another computer, the DNS server re-directs the requesting computer to another DNS server.

The Domain Name Service is structured as a hierarchy similar to the IP routing hierarchy. The computer requesting a name resolution will be re-directed 'up' the hierarchy until a DNS server is found that can resolve the domain name in the request. Figure 6 illustrates a portion of the hierarchy. At the top of the tree are the domain roots. Some of the older, more common domains are seen near the top. What is not shown are the multitude of DNS servers around the world which form the rest of the hierarchy? When an Internet connection is setup (e.g. for a LAN or Dial-Up Networking in Windows), one primary and one or more secondary DNS servers are usually specified as part of the installation. This way, any Internet applications that need domain name resolution will be able to function correctly. For example, when you enter a web address into your web browser, the browser first connects to your primary DNS server. After obtaining the IP address for the domain name you entered, the browser then connects to the target computer and requests the web page you wanted.

Application Protocols: HTTP and the World Wide WebOne of the most commonly used services on the Internet is the World Wide Web (WWW). The application protocol that makes the web work is Hypertext Transfer Protocol or HTTP. Do not confuse this with the Hypertext Markup Language (HTML). HTML is the language used to write web pages. HTTP is the protocol that web browsers and web servers use to communicate with each other over the Internet. It is an application level protocol because it sits on top of the TCP layer in the protocol stack and is used by specific applications to talk to one another. In this case the applications are web browsers and web servers.

HTTP is a connectionless text based protocol. Clients (web browsers) send requests to web servers for web elements such as web pages and images. After the request is serviced by a server, the connection between client and server across the Internet is disconnected. A new connection must be made for each request. Most protocols are connection oriented. This means that the two computers communicating with each other keep the connection open over the Internet. HTTP does

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not however. Before an HTTP request can be made by a client, a new connection must be made to the server.

When you type a URL into a web browser, this is what happens: 1. If the URL contains a domain name, the browser first connects to a domain name server and

retrieves the corresponding IP address for the web server. 2. The web browser connects to the web server and sends an HTTP request (via the protocol stack)

for the desired web page. 3. The web server receives the request and checks for the desired page. If the page exists, the web

server sends it. If the server cannot find the requested page, it will send an HTTP 404 error message. (404 mean 'Page Not Found' as anyone who has surfed the web probably knows.)

4. The web browser receives the page back and the connection is closed. 5. The browser then parses through the page and looks for other page elements it needs to complete

the web page. These usually include images, applets, etc. 6. For each element needed, the browser makes additional connections and HTTP requests to the

server for each element. 7. When the browser has finished loading all images, applets, etc. the page will be completely loaded

in the browser window.

Most Internet protocols are specified by Internet documents known as a Request for Comments or RFCs. RFCs may be found at several locations on the Internet. See the Resources section below for appropriate URL's. HTTP version 1.0 is specified by RFC 1945.

Uniform Resource Locators or URLs:A Uniform Resource Locator or URL is the address of a document you'll find on the WWW. Your

WWW browser interprets the information in the URL in order to connect to the proper Internet server and to retrieve your desired document. Each time you click on a hyperlink in a WWW

document, you're actually instructing your browser to find the URL that's embedded within the hyperlink. 

The elements in a URL: Protocol: //server's address/filename Hypertext protocol: http://www.aucegypt.eduGopher protocol: gopher://gopher.umm.tc.eduFile Transfer Protocol: ftp://ftp.dartmouth.edu

Telnet Protocol: telnet://pac.carl.orgNews Protocol: news: alt.rock-n-roll.stones

WWW Clients, or "Browsers":

The program you use to access the WWW is known as a browser because it "browses" the WWW and requests these hypertext documents. Browsers can be graphical, like Netscape and Mosaic,

allowing you to see and hear the graphics and audio; text-only browsers (i.e., those with no sound or graphics capability) are also available. All of these programs understand 

http and other Internet protocols such as FTP, gopher, mail, and news, making the WWW a

Transmission Control ProtocolUnder the application layer in the protocol stack is the TCP layer. When applications open a connection to another computer on the Internet, the messages they send (using a specific application layer protocol) get passed down the stack to the TCP layer. TCP is responsible for routing application protocols to the correct application on the destination computer. To accomplish

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this, port numbers are used. Ports can be thought of as separate channels on each computer. For example, you can surf the web while reading e-mail. This is because these two applications (the web browser and the mail client) used different port numbers. When a packet arrives at a computer and makes its way up the protocol stack, the TCP layer decides which application receives the packet based on a port number. TCP works like this: When the TCP layer receives the application layer protocol data from above, it segments it into manageable 'chunks' and then adds a TCP header with specific TCP information to each 'chunk'. The information contained in the TCP header includes the port number of the application the data needs to be sent to. When the TCP layer receives a packet from the IP layer below it, the TCP layer strips the TCP header data from the packet, does some data reconstruction if necessary, and then sends the data to the correct application using the port number taken from the TCP header. This is how TCP routes the data moving through the protocol stack to the correct application. TCP is not a textual protocol. TCP is a connection-oriented, reliable, byte stream service. Connection-oriented means that two applications using TCP must first establish a connection before exchanging data. TCP is reliable because for each packet received, an acknowledgement is sent to the sender to confirm the delivery. TCP also includes a checksum in it's header for error-checking the received data. The TCP header looks like this:

Notice that there is no place for an IP address in the TCP header. This is because TCP doesn't know anything about IP addresses. TCP's job is to get application level data from application to application reliably. The task of getting data from computer to computer is the job of IP.

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Internet ProtocolUnlike TCP, IP is an unreliable, connectionless protocol. IP doesn't care whether a packet gets to its destination or not. Nor does IP know about connections and port numbers. IP's job is too send and route packets to other computers. IP packets are independent entities and may arrive out of order or not at all. It is TCP's job to make sure packets arrive and are in the correct order. About the only thing IP has in common with TCP is the way it receives data and adds its own IP header information to the TCP data. The IP header looks like this:

Above we see the IP addresses of the sending and receiving computers in the IP header. Below is what a packet looks like after passing through the application layer, TCP layer, and IP layer. The application layer data is segmented in the TCP layer, the TCP header is added, the packet continues to the IP layer, the IP header is added, and then the packet is transmitted across the Internet.

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Internet securityInternet security is a branch of computer security specifically related to the Internet. Its objective is to establish rules and measures to use against attacks over the Internet. The Internet represents an insecure channel for exchanging information leading to a high risk of intrusion or fraud, such as phishing. Different methods have been used to protect the transfer of data, including encryption.

Security problemsMost of the security problems encountered on the Internet are due to human mistakes. The first level of security "leaks" usually occurs during the developpement of the website. If a website developer doesn't correctly plan or proof test his scripts, an eventual hacker could extract confidential information from the website itself. This is usually done by exploiting particular errors or by inserting some particular code snippets into an input field or website URL. The usual way to fix this problem is to make better planning when coding your website and to further test your scripts, especially those dealing with private data's. Another kind of security problem are problems due to users neglecting their own private information's. A good example of this kind of neglection is when someone gives away his or her email address on a public forum. Some "crawler bots" (small programs coded to collect email addresses) could find the address and add it to a mass-mail list, sending spam to the user. This may not be a dangerous "security" problem but the same can also happen with user names and passwords. Most of the big hacking cases occur simply because an important user of a particular network gave away his private information. The main way to fix this problem is to be very careful to who and how you display confidential data's. The best thing being simply not to display them. Another big security problem is the download of virus-infected files. Most of the virus will usually not affect your computer; still, some of them might contain damageable programs for your computer or even allow a distant user to take control of your computer. These programs are called a "Trojan Horse". While some people may believe the opposite, it is impossible for someone to download potentially damaging files to your computer without your content, as long as you don't let your computer filter your downloads. At the same time, it is barely impossible to simply "get a virus" by surfing on the Internet. Virus mostly come with downloaded files that you usually consented to download or in attached email files that you opened without previously checking it. That being said, the trick here is again to be extremely careful when you download a file. Peer-to-peer networks are also good virus hives and it is preferable to stay away from them. The last and probably most uncommon internet security problem is hacking itself. True hacking usually means that the hacker had no or few information on his target and does most of the breakthrough with his own knowledge. Common users are usually not the target of hackers; hackers will usually try to get through security barrier of big organization's Internet servers or try to hack Website Servers. They usually get to do so by using some software engineering flaws that have yet to be fixed (most of Windows Xp auto patching aims to fix these flaws for example). At large, there is no particular way to help in this case, unless you're the developer of that software. Simply report the case to the developer and wait for a security fix or a new version with better security. Hopefully, some companies actively work at the elimination of all these problems. For example, Norton provides users with a whole array of security tools (e.g.: Norton Antivirus) that do make a difference when it comes to clean up (virus-wise) your computer. Microsoft is also developing a software called "Microsoft AntiSpyware" that aims to help the users keep their privacy, eliminating history data's and Spywares. What you need to keep in mind is that most of the security problems on the Internet are due to the users misunderstanding of the media or human mistakes. You need to be extremely careful when transferring files or displaying private information and pay close attention to new kinds of virus or security leaks. It's best to also keep in mind that the Internet is not the only network, local or wireless networks are as much vulnerable than is the Net.

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Types of securityNetwork layer securityTCP/IP can be made secure with the help of cryptographic methods and protocols that have been developed for securing communications on the Internet. These protocols include SSL and TLS for web traffic, PGP for email, and IPsec for the network layer security.IPsec ProtocolThis protocol is designed to protect communication in a secure manner using TCP/IP. It is a set of security extensions developed by IETF, and it provides security and authentication at the IP layer by using cryptography. To protect the content, the data is transformed using encryption techniques. There are two main types of transformation that form the basis of IPsec: the Authentication Header (AH) and Encapsulating Security Payload (ESP). These two protocols provide data integrity, data origin authentication, and anti-replay service. These protocols can be used alone or in combination to provide the desired set of security services for the Internet Protocol (IP) layer.The basic components of the IPsec security architecture are described in terms of the following functionalities: Security protocols for AH and ESP Security association for policy management and traffic processing Manual and automatic key management for the internet key exchange (IKE) Algorithms for authentication and encryptionThe set of security services provided at the IP layer includes access control, data origin integrity, protection against replays, and confidentiality. The algorithm allows these sets to work independently without affecting other parts of the implementation. The IPsec implementation is operated in a host or security gateway environment giving protection to IP traffic.Electronic mail security (E-mail)Pretty Good Privacy (PGP)PGP provides confidentiality by encrypting messages to be transmitted or data files to be stored using an encryption algorithm such 3DES or CAST-128. Email messages can be protected by using cryptography in various ways, such as the following: Signing an email message to ensure its integrity and confirm the identity of its sender. Encrypting the body of an email message to ensure its confidentiality. Encrypting the communications between mail servers to protect the confidentiality of both the message body and message header.The first two methods, message signing and message body encryption, are often used together; however, encrypting the transmissions between mail servers is typically used only when two organizations want to protect emails regularly sent between each other. For example, the organizations could establish a virtual private network (VPN) to encrypt the communications between their mail servers over the Internet. Unlike methods that can only encrypt a message body, a VPN can encrypt entire messages, including email header information such as senders, recipients, and subjects. In some cases, organizations may need to protect header information. However, a VPN solution alone cannot provide a message signing mechanism, nor can it provide protection for email messages along the entire route from sender to recipient.Multipurpose Internet Mail Extensions (MIME)MIME transforms non-ASCII data at the sender's site to Network Virtual Terminal (NVT) ASCII data and delivers it to client's Simple Mail Transfer Protocol (SMTP) to be sent through the Internet. The server SMTP at the receiver's side receives the NVT ASCII data and delivers it to MIME to be transformed back to the original non-ASCII data.Secure/Multipurpose Internet Mail Extensions (S/MIME)S/MIME provides a consistent means to securely send and receive MIME data. S/MIME is not only limited to email but can be used with any transport mechanism that carries MIME data, such Hypertext Transfer Protocol (HTTP).

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Message Authentication CodeA Message Authentication Code is a cryptography method that uses a secret key to encrypt a message. This method outputs a MAC value that can be decrypted by the receiver, using the same secret key used by the sender. The Message Authentication Code protects both a message's data integrity as well as its authenticity.

FirewallsA firewall controls access between networks. It generally consists of gateways and filters which vary from one firewall to another. Firewalls also screen network traffic and are able to block traffic that is dangerous. Firewalls act as the intermediate server between SMTP and HTTP connections.

Role of firewalls in Internet security and web securityFirewalls impose restrictions on incoming and outgoing packets to and from private networks. All the traffic, whether incoming or outgoing, must pass through the firewall; only authorized traffic is allowed to pass through it. Firewalls create checkpoints between an internal private network and the public Internet, also known as choke points. Firewalls can create choke points based on IP source and TCP port number. They can also serve as the platform for IPsec. Using tunnel mode capability, firewall can be used to implement VPNs. Firewalls can also limit network exposure by hiding the internal network system and information from the public Internet.

Viruses and antivirusViruses

Viruses are programs that can replicate their structures or effects by infecting other files or structures on a computer. The common use of a virus is to take over a computer to steal data.Trojan horseA Trojan horse (commonly known as a Trojan) is a general term for malicious software that pretends to be harmless so that a user willingly allows it to be downloaded onto the computer.SpywareThe term spyware refers to programs that surreptitiously monitor activity on a computer system and report that information to others without the user's consent.WormsWorms are programs that can replicate themselves throughout a computer network, performing malicious tasks throughout.BotnetA botnet is a network of "zombie" computers that have been taken over by a "bot" that performs large-scale malicious acts for the creator of the botnet.

AntivirusAntivirus programs and Internet security programs are useful in protecting a computer or programmable device from malware.Such programs are used to detect and usually eliminate viruses; however, it is now common to see security suites, containing also firewalls, anti-spyware, theft protection, and so on to more thoroughly protect users. Traditionally, a user would pay for antivirus software; however, computer users now can, and do, download from a host of free security applications on the Internet.

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Advantages of Internet1) E-mail: Email is now an essential communication tools in business. With e-mail you can send and receive instant electronic messages, which works like writing letters. Your messages are delivered instantly to people anywhere in the world, unlike traditional mail that takes a lot of time. Email is free and fast when compared to telephone, fax and postal services. Just compare the costs of sending out physical mailing to 5,000 addresses, with the costs of an e-mailing to 50.000 e-mail addresses.2) 24 hours a day - 7 days a week: Even if no staff is in your office, visitors will come to your website using Internet.3) Information: Information is probably the biggest advantage internet is offering. There is a huge amount of information available on the internet for just about every subject, ranging from government law and services, trade fairs and conferences, market information, new ideas and technical support. You can almost find any type of data on almost any kind of subject that you are looking for by using search engines like google, yahoo, msn, etc.4) Online Chat: You can access many ‘chat rooms’ on the web that can be used to meet new people, make new friends, as well as to stay in touch with old friends. 5) Services: Many services are provided on the internet like net banking, job searching, purchasing tickets, hotel reservations, guidance services on array of topics engulfing the every aspect of life.6) Communities: Communities of all types have sprung up on the internet. It's a great way to meet up with people of similar interest and discuss common issues.7) Ecommerce: Along with getting information on the Internet, you can also shop online. There are many online stores and sites that can be used to look for products as well as buy them using your credit card. You do not need to leave your house and can do all your shopping from the convenience of your home. It has got a real amazing and wide range of products from household needs, electronics to entertainment.8) Software Downloads: You can freely download innumerable, software's like utilities, games, music, videos, movies, etc from the Internet.9) Entertainment : Internet functions as a popular medium of entertainment. A wide variety of entertainment including video games, music, movies, chat room, news and others can be accessed through the Internet.

Disadvantages of InternetTheft of Personal information: Electronic messages sent over the Internet can be easily snooped and tracked, revealing who is talking to whom and what they are talking about. If you use the Internet, your personal information such as your name, address, credit card, bank details and other information can be accessed by culprits. If you use a credit card or internet banking for online shopping, then your details can also be ‘stolen’. Negative effects on family communication: Although there are conflicting research findings on this topic, an article published by Science Daily reported that time spent on the Internet was associated with later declines in within house family communication and a decrease in the number of friends and acquaintances with which they kept ties.Internet addiction: There is some controversy over whether it is possible to actually be addicted to the Internet or not. Some researchers claim that it is simply people trying to escape their problems in an online world and cannot be classified as an addiction. Other psychologists believe that Internet addiction is a true psychological disorder with definable symptoms. The symptoms are comparable to any addiction, withdrawal, loss of relationships or job and significant time consumption.

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Children using the Internet has become a big concern. Most parents do not realize the dangers involved when their children log onto the Internet. When children talk to others online, they do not realize they could actually be talking to a harmful person. Moreover, pornography is also a very serious issue concerning the Internet, especially when it comes to young children. There are thousands of pornographic sites on the Internet that can be easily found and can be a detriment to letting children use the Internet. Virus threat: Today, not only are humans getting viruses, but computers are also. Computers are mainly getting these viruses from the Internet. Virus is is a program which disrupts the normal functioning of your computer systems. Computers attached to internet are more prone to virus attacks and they can end up into crashing your whole hard disk, causing you considerable headache. Spamming: Is often viewed as the act of sending unsolicited email. This multiple or vast emailing is often compared to mass junk mailings. It needlessly obstruct the entire system. Most spam is commercial advertising, often for dubious products, get-rich-quick schemes, or quasi-legal services. Spam costs the sender very little to send -- most of the costs are paid for by the recipient or the carriers rather than by the sender.

The Disadvantages of the Internet at HomeThe Internet at home presents both problems and opportunities. The advent of the Internet as a common feature in many homes has given parents and children access to tremendous resources for information and communication, but it has also posed problems for many individuals and families.

IsolationUsing the Internet for long periods of time can isolate people from family and friends. Though many develop online relationships, these "cyber" buddies cannot replace "real life" socializing.

AddictionIt is possible for Internet users to become habitually addicted. Though different from chemical addiction, it is a real problem as some lose employment and suffer other adverse effects from overuse.

Inaccurate InformationThough there are many legitimate websites full of factual information, there are a plethora of sites with inaccurate information, and it is often hard to differentiate between them.

Hacking of Personal InformationProviding personal information online when shopping or banking can result in hackers gaining access to private data that can be used to steal your funds and even your identity.

VirusesGoing online often means subjecting your computer to viruses that can crash your system, causing you to lose important files and sometimes destroying your operating system.

Inappropriate WebsitesChildren can often stumble upon or seek out inappropriate websites when using the Internet at home, which can be dangerous if the child shares personal information.

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Predictions for the Future of the Internet1. Audio web surfing

Building the web with standards and accessibility in mind brings the Internet to as wide an audience as possible. With the importance of accessibility getting the recognition it deserves lately, I think screen readers will soon take a front seat as a common means for surfing a site for a much broader audience. I’m calling it: people on the train with headphones attached to their mobile device while Text-to-Speech reads them the latest articles from their favorite sites. HTML5 is a step in an awesome direction with regards to easy reference points; header, footer, nav, section, and article could be logical jump-to points by audible instruction. Rather than reading and clicking, the audience can tell the browser where they want to go with spoken commands. From an input standpoint, speech recognition has come a long way in the last decade. Bell Canada has been playing with the audio-attendant "Emily" since 2003. When you call, Emily will give a familiar greeting and ask how she can be of assistance. By simply telling her what you want – it can range from simple commands like "Billing" to more complicated sentences like "I want to talk about my Long Distance package" – she will direct your call accordingly.It’s not perfect: about a quarter of the time, she’ll reply that she didn’t understand my request. While it can still be awkward, it works. Six years after first encountering this on the phone, I can actually say I prefer telling "her" what I want to the old "Press 1 for…" menu. It’s not an Internet application; but it shows that audio navigation works well, and can be efficient.When it comes to output, Text-to-Speech is getting better all the time, a vast improvement over the last decade or so: Speakonia 1997 vs. the more modern Kindle and OSX. It has gone from lifeless and robotic to something a lot more palatable in the last few years, and seems to continue to improve.

Hal 9000

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Audio surfing could be perfect for the aforementioned commuters, children learning to read, step-by-step tutorials as well as the casual multitasking user. While it won’t be everyone’s cup of tea, any traffic to a site by an audience who cares is welcome.For web developers, there may be new accessibility opportunities especially for multi-lingual sites. Who knows, this might be another nail in the Flash coffin.If you think audio surfing could hit the mainstream say "amazing" now – and don’t forget to add my site to your playlist.2. Web surf on any deviceIt seems the tech industry is eager to integrate the Internet into every device these days. It’s the equivalent to adding a digital clock to a coffee maker. Why not? Adding a touch-screen to your fridge and other appliances might create new opportunities and challenges for interfacing.

Wifi PredatorContent is king – no matter what. As seemingly redundant or over the top it might seem to have a screen built into the kitchen counter – if it doubles as a cutting board, all the better.

Dishwasher SafeMore widespread Internet delivery will mean reaching a wider audience – like the elusive "Mom" demographic. An issue keeping some users away is that the Internet can be a vast and scary place. These everyday devices married with technology don’t have to serve all of the web’s content though. They are niche items, and as such, they can deliver relevant niche content. The cutting board doesn’t need to be able to easily reach unrelated sites like LOLCats or Ebay, if it had a cooking oriented home screen complete with grocery list, meal suggestions, links and unit conversions, it would be less daunting and far more appealing to the target demographic of the product – even to those who don’t consider themselves to be Internet savvy.The major weakness to the increase of connected devices comes in the same flavor as the raging Net Neutrality issues being discussed today. If the Internet is tied into content devices like

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televisions, broadcasting companies might start pulling more of their annoying control-freak shenanigans in an attempt to capture a greater audience. This will be temporary; the battle of old-media vs. the Internet has only one ending (hint: the loser starts with the letter "o" followed by the letters "ld-media").I hope that with the advent of new devices comes an easier way for developers to "browser sniff" their traffic and serve up the appropriate content. If device manufacturers adhere to accessibility standards, the results could be amazing.3. Input revisitedThe recent boom in smart phone devices has shown us that tiny screens and suddenly awkward digits can sometimes make for a cumbersome user experience. Our traditional concepts of input applied to the next generation could be confounded more as the devices and environments change. At 6′ 4", I don’t relish the idea of hunching over a wall-mounted screen that has my 5′ 2" coworker in mind.

10/GUIRecently, Clayton Miller shared his concept for multi-touch computing, the 10/GUI (here’s a video). This video bears watching, drooling over, and retweeting with the word "Want".

From the movie, Minority Report He quickly illustrates the point that a mouse, as ubiquitous as it is, weakly offers only two sets of coordinates, while the users are capable of so much more. Touch screen technology is only scratching the surface on intuitive approaches to interfacing. There is lots of room for growth here. Simple Gesture implementation on the track pad in OSX is so good that using gestureless laptops becomes unthinkable. The new Magic Mouse may be just the beginning.I think we’re all ready to compute better, but this could easily be a disaster. If the new input technology is universal like the mouse was, everyone wins. I think it’s more likely that many

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hardware manufacturers will try to invent their own GUIs. This would mean many learning curves, and would be generally painful to deal with.4. Mobile networkingBluetooth is known for allowing wireless communication, like with hands-free systems in cars, and the some of the latest mice and keyboards (like the aforementioned Magic Mouse). It also may be the future for mobile networking and P2P interactions. Check out this Android 2.0 "Pong" demonstration:Does that blow your mind? Imagine interacting on a website with a friend, or with the advertisement at the bus shelter. The possibilities become staggering.

Source: Tom BielliSome non-gaming applications come readily to mind:Simultaneous dual login for greater site security Online training sessions and remote-access troubleshooting On location interactions with stores, tourist attractions or public servicesFor years, the Internet has been about serving the singular user. With the growing need and importance of online community, multiple-user experiences seem like the next logical step.5. The end of .com dominationFor as long as the Internet has been around, .com has been the assumed default extension for websites (regardless of whether or not the site was "commercial" or not). For a while, there was almost a negative stigma to not having the .com for your brand, company or personal site. How many times has traffic meant for your site ended up at the .com equivalent?With all common words and combinations taken (even just parked on), people turn to other extensions, invent words, or turn to crazy spelling. In the very near future new extensions will be popping more often. Not only that, but I think trending may follow in that vein. I also predict that Domain Service giants like GoDaddy will start selling "Extension Subscriptions" where you can guarantee yourself the various extensions for your domain name.More extensions have some definite advantages, and some drawbacks. On the plus side, when adding a link to some print materials, maybe we’ll be able to drop the "www", which is often used now as a cue that "this is in fact a URL". One silly drawback could be the increase in convoluted sub-domain cleverness like "del.icio.us".I would also like to raise the question, how long will we need these addresses? Remembering and using URLs to point at sites works well, but doesn’t seem the most efficient way to bring site users to websites. One day, search engines, RSS readers, communities and networks may reduce direct traffic to a trickle, making the .com even less important.

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6. IE6 stops being usedI’ll admit this seems like the most unlikely out of all the other predictions. Maybe it won’t happen in our lifetime, but it is somehow feasible that it could happen.

Here’s how it could go down: in the distant future, some impending disaster will cause mankind to have to abandon Earth and head for a planet light years away. The question of who and what can go to the new planet will of course be a major issue, and sadly IE6 won’t make it off of the doomed Earth. The escaping web designers and developers will enjoy a short-lived period of joy as there will always be some misfit version of Internet Explorer to support.

The Future of the InternetJust as the Internet revolutionized how the world accessed information and communicated through the 1990's, the ongoing development in speed, bandwidth, and functionality will continue to cause fundamental changes to how our world operates for decades to come. Some of the major trends shaping the future of the Internet are summarized below, along with extrapolated predictions:

Globalism. The future of the Internet global distribution of information and knowledge at lower and lower cost will continue to lift the world community for generations to come. People will have access to any information they wish, get smarter sooner, and be more aware of the world outside their local environment. A better informed humanity will make better macro-level decisions, and an increasingly integrated world will drive international relations towards a global focus. Attachments to countries will marginally decrease, and attachments to the Earth as a shared resource will significantly increase. Communities. The future of the Internet communications revolution is ongoing, now uniting communities as it recently united networks. Not everything about the Internet is global; an interconnected world is also locally interconnected. The Internet will increasingly be used for communications within communities as much as across countries. Local communities will organize in virtual space and take increasing advantage of group communication tools such as mailing lists, newsgroups, and websites, and towns and cities will become more organized and empowered at the neighborhood level. At the same time, communities will be as profoundly affected by the capabilities the Internet is bringing to individual communications, providing individuals in the once isolating city the ability to easily establish relationships with others in their local area by first meeting in cyberspace. From hobby clubs to political organizations to social networking, Internet applications will change expectations of geographically oriented community organizations, and provide increasingly wide choices to individuals who wish to participate in local communities that share their interests. Virtual reality. The future of the Internet technological revolution will continue to be made in man's image. Experiments with wide area voice and video communications on the Internet began to be held in the early 1990's. Voice over IP (VOIP) began to be used regularly

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for long distance voice communications in 2002. Internet video phones won't be far behind. With the continued doubling of computer capability every couple of years, the ability of technology to process the complex analog environment that humans live in -- "reality" -- will continue to increase, and will be increasingly integrated with the Internet. Three dimensional graphics will become more sophisticated, and virtual reality interfaces such as viewers and tactile feedback systems will become more realistic. The technology will be applied to innovative ways to navigate the Internet's information universe, for hyper-realistic gaming, and for group communications. There will come a day when you will be able to have dinner with a group of friends each in a different city, almost as though you were in the same room, although you will all have to bring your own food.Virtual reality applications will not only better and better reflect the natural world, they will also have the fluidity, flexibility, and speed of the digital world, layered on the Internet, and so will be used to create apparently magical environments of types we can only now begin to imagine. These increasingly sophisticated virtual experiences will continue to change how we understand the nature of reality, experience, art, and human relations. Bandwidth. The future of the Internet growth in bandwidth availability shows little sign of flattening. Large increases of bandwidth in the 10 Mbps range and up will continue to be deployed to home users through cable, phone, and wireless networks. Cable modems and telephone-based DSL modems will continue to spread high speed Internet throughout populated areas. High resolution audio, video, and virtual reality will be increasingly available online and on demand, and the cost of all kinds of Internet connections will continue to drop. Wireless. The future of Internet wireless communications is the end-game. Wireless frequencies has two great advantages: (a) There are no infrastructure start-up or maintenance costs other than the base stations, and (b) It frees users to become mobile, taking Internet use from one dimension to three. Wireless Internet networks will offer increasingly faster services at vastly lower costs over wider distances, eventually pushing out physical transmission systems. The Internet's open TCP/IP design was originally inspired by use of radio communications networks in the 1970's. The wireless technologies experimented with in the 1990's were continually improved. By the early 2000's, several technologies provided reliable, secure, high bandwidth networking that worked in crowded city centers and on the move, providing nearly the same mobility for Internet communications as for the cellular phone. Grids. The future of the Internet grid movement is as inevitable as the spread of the Internet seems now. The connection of thousands of computers on the Internet together to solve problems, often called grid computing, will continue to evolve and change many areas of human endevour. In a large scale example of the connected Internet fostering technological cooperation, un-used computer cycles from home users across the world will be harnessed together to provide enormous reservoirs of computer power for all sorts of purposes. Increasingly used for scientific and engineering research, grids can create processing powerhouses far larger than any one organization by itself. Integration. The future of the Internet integration with an increasing number of other technologies is as natural as a musician's experimentation with notes. The Internet will become increasingly integrated with phones, televisions, home appliances, portable digital assistants, and a range of other small hardware devices, providing an unprecedented, nearly uniform level of integrated data communications. Users will be able to access, status, and control this connected infrastructure from anywhere on the Internet. One of the leading efforts to define the future of the next generation Internet is the Internet2 project, which grew out of the transition of the NSFNET to the Very High Speed Backbone Network Service (vBNS, vbns.net). The vBNS supported very high bandwidth research applications, and was established in 1995 as a cooperative agreement between MCI and the National Science Foundation.

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