Computer Science

Q. Define e-commerce? What are the benefits of using e-commerce?

The term ‘electronic commerce’ has evolved from electronic shopping, to imply all aspects of business and market processes enabled by the Internet and World Wide Web technologies.

According to Philip Kotler : E-commerce can be defined as a general term for buying and selling process that is supported by electronic means.
Electronic commerce, also known as e-business, a term for all kinds of business that are established electronically especially over the Internet. This includes both electronic sale (internet shops) and B2B transactions, i.e. business between two companies. It is any online transaction of buying and selling where business is done via Electronic Data
Interchange (EDI). E-Commerce can be defined from different perspectives – 1. Communications perspective, 2. Business process perspective, 3. Service perspective and 4. Online perspective.

Basic Benefits of E-Commerce
The major benefits are increasing sales and decreasing costs. The other benefits are as follows:
1. Increased accessibility to customers
i)Allows people to carry out operations without barriers of time i.e. 24 hours a day, seven days a week.
ii) To reach out to global consumers easily and is also cost effective.
iii) It helps business to reach out new markets.
iv) Consumers and suppliers can be directly approached over the Internet.
v) Acquisition of new consumers over the internet is considerably cheaper..

2. Convenience of making comparisons:
E-commerce helps consumers to make comparisons while shopping . Automated online shopping assistants called hopbots score are available to find deals on anything from flowers to perfume

3. Increased Profitability
i) The direct cost to sale for an order taken from an web site is lower as compared to traditional means. Moreover processing errors are virtually eliminated in e-selling besides being faster and more convenient to visitor.
ii) It provides the solution by decimating the costs, which are incurred.

4. Innovation:
E-commerce enables business organization to create new products or services.

5.Improvement in consumer service:
There is a direct benefit in improvement of consumer service. High levels of customer satisfaction generate increased sales and increased profits.

6. Tangible advantages:
From the buyer’s perspective e-commerce provides a lot of tangible advantages:
i. Reduction in buyers sorting out time
ii Better buyer decisions.
iii.Less time spent in resolving invoice and order discrepencies.
iv. Increased opportunities for buying alternative products.

7. Stratergic Benefits:
It helps to reduce delivery time,labour cost and also the cost incurred in the following areas:
i) Document prepration.
ii) Error detection and correction.
iii) Reconciliation.
iv) Mail Prepration.
v) Telephone calling.
vi) Data Entry.
vii)Overtime.
viii)Supervision Expenses.

Q. Discuss in brief the following terms
i) Telnet ii) http (hypertext transfer protocol) iii) Remote login

i) Telnet:
It is a terminal emulation program for TCP/IP networks such as the Internet. The Telnet program runs on your computer and connects your PC to a server on the network. One can then enter commands through the Telnet program and they will be executed as if you were entering them directly on the server console. This enables one to control the server and communicate with other servers on the network. To start a Telnet session, one must log in to a server by entering a valid username and password. Telnet is a common way to remotely control Web servers.

(ii) Http :
Hyper Text Transfer Protocol; The WWW protocol that performs the request and retrieve functions of a server. Commonly seen as the first part of a website address. It is the communication protocol used to connect to servers on the World Wide Web. The primary function of HTTP is to establish a connection with a Web server and transmit HTML pages to the user's browser.

(iii) Remote Login
A login that allows a user terminal to connect to a host computer via a network or direct telecommunications link, and to interact with that host computer as if the user terminal were directly connected to that host computer. Gives the same functionality of telnet, with the added functionality of not requiring a password from trusted clients, which can also create security concerns. Protocols such as TELNET and RLOGIN were developed for terminal users to use their terminals as if they were directly connected to a remote system. UNIX systems, with their predominately terminal-oriented interface, still make heavy use of these protocols.

Q. Explain briefly how firewalls protect network.

A firewall is simply a program or hardware device that filters the information coming through the Internet connection into your private network or computer system. If an incoming packet of information is flagged by the filters, it is not allowed through the network. A firewall gives a company tremendous control over how people use the network. Firewalls use one or more of three methods to control traffic flowing in and out of the network:

• Packet filtering - Packets (small chunks of data) are analyzed against a set of filters. Packets that make it through the filters are sent to the requesting system and all others are discarded.

• Proxy service - Information from the Internet is retrieved by the firewall and then sent to the requesting system and vice versa
• Stateful inspection - A newer method that doesn't examine the contents of each packet but instead compares certain key parts of the packet to a database of trusted information.

Q. Explain the use of SSL to secure the network.

SSL (Secure Sockets Layer), is a protocol developed by Netscape for transmitting private documents via the Internet. SSL works by using a private key to encrypt data that's transferred over the SSL connection. Both Netscape Navigator and Internet Explorer support SSL, and many Web sites use the protocol to obtain confidential user information, such as credit card numbers.

The SSL standard is not a single protocol, but rather a set of accepted data transfer routines that are designed to protect the integrity of transmitted messages. SSL relies on certificates - digital identification cards - and keys.

Two types of keys are used as ciphers to encrypt and decrypt data. Private keys are issued to entities and are never given out. Public keys are given out freely. Both keys are necessary for authentication routines. Data encrypted with the public key cannot be decrypted with the same key. The private key must be used.  

Q. Explain network security. What are the types of security features used in client server types of network?

Network security means the protection of networks and their services from unauthorized access, modification, destruction or disclosure. It provides for assurance that a network performs its critical functions correctly and there are no harmful side effects. Security features used in Client-Server types of network are as follows :

i) Digital Signatures
ii) Encryption / Decryption
iii) Secure Socket Layer (SSL)
iv) Firewalls.
V)IDS/IPS

Q. What is Public Key Cryptography? What are its advantages and disadvantages?

Public-key cryptography is a form of modern cryptography which allows users to communicate safely without previously agreeing on a shared secret key There are a number of significant practical difficulties in this approach to distributing keys.

Public-key cryptography was invented to address these drawbacks — with public-key cryptography, users can communicate with safety over an insecure channel without having to agree upon a key beforehand.

Public-key algorithms typically use a pair of two related keys — one key is private and must be kept secret, while the other is made public and can be widely distributed; it should not be possible to deduce one key of a pair given the other.

Advantages
(i) Increased security and convenience
(ii) Electronic records may be authenticated by affixing digital signatures

Disadvantages
Used to encrypt a secret key which is used to encrypt the bulk of a file or message. Such a protocol is called a digital envelope Public-key cryptography is not necessary and secret-key cryptography alone is sufficient.
This includes environments where secure secret-key agreement can take place, for example by users meeting in private.