O LEVEL- INTERNET TECHNOLOGY & WEB DESIGN


O LEVEL-PAPER 2nd -- M2-R4 :


INTERNET TECHNOLOGY & WEB DESIGN




THESE ARE THE QUESTIONS WHICH FREQUENTLY ASKED IN 



  LAST 10 YEARS -----



Cybercrime

Cybercrime is defined as a crime in which a computer is the object of the crime (hacking, phishing, spamming) or is used as a tool to commit an offense (child pornography, hate crimes). Cybercriminals may use computer technology to access personal information, business trade secrets or use the internet for exploitative or malicious purposes. Criminals can also use computers for communication and document or data storage. Criminals who perform these illegal activities are often referred to as hackers.
Cybercrime may also be referred to as computer crime.
Common types of cybercrime include online bank information theft, identity theft, online predatory crimes and unauthorized computer access. More serious crimes like cyberterrorism are also of significant concern.
Cybercrime encompasses a wide range of activities, but these can generally be broken into two categories:
  • Crimes that target computer networks or devices. These types of crimes include viruses and denial-of-service (DoS) attacks.
Crimes that use computer networks to advance other criminal activities. These types of crimes include cyberstalking, phishing and fraud or identity theft



Definition of Digital Signature

The Digital Signature is a type of electronic signature and follows the particular standards. It imparts independent verification and tamper evidence. The verification of digital signatures is done by the trusted third party commonly referred to a Certificate Authority.
Certificate authorities bind the user’s identity to a PKI-based digital certificate which allows the user to apply digital signatures to the document and the cloud-based signing platforms. When a digital signature is employed to a document, a cryptographic operation attaches digital certificate with the data into one unique fingerprint.
The message is signed by the private key of the sender which is only known to him/her; this ensures authentication of the message source. The message and its signature cannot be changed thenceforth signing a message. Sender and receiver do not have to worry about transit alteration without the private key, the message and its signature could never be altered. The sender of the message cannot refuse having signed a signature if it is valid. Digital signature distinctively correlates with the corresponding message and renders integrity.
Digital signatures need not separate from a message or document for using it in another document. These types of signatures depend on the document as well as on the signer.

Digital signature scheme steps:

·         Key generation: The public key and its correlated private key of the user is computed in this step.
·         Signing: The corresponding message is signed by the user with his/her private key.
·         Verification: In this step, the signature for a provided message against the public key is verified.





Definition of URL

URL (Uniform Resource Locator) can be defined as a string of characters which refers to address. It is the most pervasively used way to locate resources on the web. It provides a method to retrieve the presentation of the physical location by describing its network location or primary access mechanism.
The protocol is described in the URL which is used to retrieve the resource and resource name. The URL contains http/https at the beginning if the resource is a web type resource. Similarly, it begins with ftp if the resource is a file and mailto if the resource is an email address. The syntax of an URL is shown below where the first part is used for protocol and rest of the part is used for the resource which consists of a domain name or program name.So a URL is used when we want to make a resource whether its web, file or email accessible through a browser.

Definition of Cookies

Cookie is a simple piece of information stored on the client computer. Whenever a user surfs the internet, the server-side code sent a small text file, i.e., cookie in the response header from an HTTP server and stored on the user’s computer. Its reason is that when the next time user visits the same site again, the cookie facilitates server to identify the client based on cookie information.
This overcomes the limitation of the HTTP protocol which is stateless. This signifies that every request from a client is served as new request even to the same server and same session.
Cookies are not intended to cause any damage to the user’s computer as they do not contain executable code. Although, cookies can be utilized to send the targeted advertisements to the users unknowingly.

Types of cookies

Transient cookie – This type of cookie live for the lifetime of the session.
Persistent cookie – This cookie remains on the user’s computer beyond the lifetime of the session.

 

Definition of CGI

The CGI (Common Gateway Interface) is an interface which handles external programs (CGI scripts) on a web server to enable the execution of the interactive web pages. CGI was developed by NCSA (National Center for Supercomputing Applications) in 1993. It resides in the server side and enables web browsers to interact with programs on the web server. For example, if a web page queries a database or a user is submitting the form information to the server at that time CGI scripts are invoked. The server passes that information on to an application in two ways GET or POST, then the application responds to the server back to the browser. In this way, browsers get some results for the user.
CGI is a stipulation, for describing a method to run CGI scripts and providing the results back to the server for those particular programs. The function of a CGI is to scan the information received from the browser and produce a proper response, after the completion of the task the CGI script is terminated. In Common Gateway Interface, the common signifies that it can operate fine in any operating system or programming language



Definition of IMAP


Internet Mail Accessing Protocol (IMAP) is also a mail accessing agent like POP3. But it is more powerful, has more features and is more complex than POP3. The POP3 protocol was found deficient in many ways. So IMAP  is introduced to overcome these deficiencies.
POP3 does not allow a user to organize mails on the mailbox. The user can not create different folders on the server. The user can not partially check the content of emails before downloading them. The user has to download an email to read it, in POP.

IMAP is used to access the mail from the mailbox at the mail server. Using IMAP the user can check the email header before downloading it. The user is able to check the content of the email for a particular string of character that too before downloading the email.
In case, the bandwidth is limited, using IMAP the user can partially downloadthe mail. It is useful in case the email contains multimedia with high bandwidth requirement. The user can create, delete or rename the mailboxes on the server. The user can also create a hierarchy of these mailboxes in a folder. This is how IMAP is more powerful than POP3 protocol.
FDDI
Stands for "Fiber Distributed Data Interface." FDDI is a group of networking specifications standardized by ANSI in the mid-1980s. An FDDI network supports data transfer speeds of 100 Mbps over a fiber optic cable and uses a rotating token to define which system can send data at any given time.
FDDI networks are comprised of two physical paths, or "rings," that transfer data in opposite directions. The primary ring carries data between systems, while the secondary ring is used for redundancy. If a system on the network causes an interruption in the primary data path, the secondary ring is used until the primary ring is functional again. A variation of FDDI, called FDDI Full Duplex Technology (FFDT), uses the secondary ring as an additional primary channel. This type of FDDI network has no redundancy, but supports data transfer rates up to 200 Mbps.


ISDN



Integrated Services Digital Network (ISDN) is a set of communication standards for digital telephone connection and the transmission of voice and data over a digital line. These digital lines are commonly telephone lines and exchanges established by the government. Before ISDN, it was not possible for ordinary telephone lines to provide fast transportation over a single line.
ISDN was designed to run on digital telephone systems that were already in place. As such, it meets telecom's digital voice network specifications. However, it took so long for ISDN to be standardized that it was never fully deployed in the telecommunications networks it was intended for.

HTTP


The Hypertext Transfer Protocol (HTTP) is an application-level protocol for distributed, collaborative, hypermedia information systems. This is the foundation for data communication for the World Wide Web (i.e. internet) since 1990. HTTP is a generic and stateless protocol which can be used for other purposes as well using extensions of its request methods, error codes, and headers.
Basically, HTTP is a TCP/IP based communication protocol, that is used to deliver data (HTML files, image files, query results, etc.) on the World Wide Web. The default port is TCP 80, but other ports can be used as well. It provides a standardized way for computers to communicate with each other. HTTP specification specifies how clients' request data will be constructed and sent to the server, and how the servers respond to these requests.

WWW


WWW stands for World Wide Web. A technical definition of the World Wide Web is : all the resources and users on the Internet that are using the Hypertext Transfer Protocol (HTTP).
A broader definition comes from the organization that Web inventor Tim Berners-Lee helped found, the World Wide Web Consortium (W3C).
The World Wide Web is the universe of network-accessible information, an embodiment of human knowledge.
In simple terms, The World Wide Web is a way of exchanging information between computers on the Internet, tying them together into a vast collection of interactive multimedia resources.


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