Computer Science

Q.  Describe in brief the history of E-Commerce.

History of E-commerce.
E-commerce began before personal computers were prevalent and has grown into a multibillion  dollar industry. By looking at the evolution of e-commerce, it will be easier to judge its trends for the future.

1984 EDI, or electronic data interchange, was standardized through ASC X12. This guaranteed that companies would be able to complete transactions with one another reliably.
1992 CompuServe offers online retail products to its customers. This gives people the first chance to buy things off their computer.
1994 Netscape arrived. Providing users a simple browser to surf the Internet and a safe online transaction technology called Secure Sockets Layer.
1995 Two of the biggest names in e-commerce are launched: Amazon.com and eBay.com.
1998 DSL, or Digital subscriber Line, provides fast, alwayson Internet service to subscribers across California. This prompts people to spend more time, and money, online.
1999 Retail spending over the Internet reaches $20 billion, according to Business.com.
2000 The U.S government extended the moratorium on Internet taxes until at least 2005.

Q. Explain briefly the generic framework for e-commerce.

Generic framework of e-commerce includes the Applications of EC (such as banking, shopping in online stores and malls, buying stocks, finding a job, conducting an auction, and collaborating electronically on research and development projects). To execute these applications, it is necessary to have Supporting Information and Organizational Infrastructure and System, which includes

• Common Business Services Infrastructure (security smart cards/authentication, electronic payment, directories/catalogs)
• Messaging and Information Distribution Infrastructure (EDI, e-mail, Hypertext Transfer Protocol)
• Multimedia Content and Network Publishing Infrastructure (HTML, Java, World Wide Web, VRML)
• Network Infrastructure (Telecom, cable TV, wireless, Internet, VAN, WAN, LAN, Intranet, Extranet) And their implementation is dependent on four major areas as supporting pillars:
• People (Buyers, Sellers, Intermediaries services, IS People, and Management),
• Public policy (Taxes, Legal, Privacy Issues, Free Speech, Domain Names)
• Technical Standards (for Documents, Security and Network Protocols, Payments)
• Organizations (Partners, competitors, Associations, Govt. Services)

The EC management coordinates the applications, Infrastructures and pillars.

Q.   What are IP addresses? How are IP addresses allocated to Computer?

IP address refers to the name of a computer on a network, like the Internet.
• An Identifier for a computer or device on a TCP/IP network, like the Internet.
• The format of an IP address is a 32-bit numeric address written as four numbers separated by periods. Each number can be zero to 255.
• The IP addresses can be in different classes/categories.

CLASS A, CLASS B, CLASS C, CLASS D, CLASS E IP ADDRESSES ARE ALLOCATED AS FOLLOWS:
Every machine on the Internet has a unique identifying number, called an IP Address. A typical IP address looks like this: 216.27.61.137

To make it easier for us to remember, IP addresses are normally expressed in decimal format as a “dotted decimal number” like the one above. But computers communicate in binary form. Look at the same IP address in binary.
11011000.00011011.00111101.10001001
The four numbers in an IP address are called octets, because they each have eight positions when viewed in binary form. It can have two different states (1or0). If you add all the positions the total number of possible combinations per octet is 28 or 256. So each octet can contain any value between 0 and 255. Combine the four octets and you get 2342 or a possible 4,294,967,296 unique values:

There are five IP classes plus certain special addresses:

Default Network-The IP address of 0.0.0.0 is used for the default network.

Class A- This class is for very large networks. IP addresses with a first octet from 1 to 126 are part of this class. The other three octets are used to identify each host. This means that there are 126 Class A networks each with 16,777,214 (2 raised to 24-2) possible hosts for a total of 2,147,483,648 (2 raised to 31) unique IP addresses. Class A networks account for half of the total available IP addresses. In class A networks, the high order bit value (the very first binary number) in the first octet is always 0.

Net Host or Node
115 24.53.107

Loop back- The IP address 127.0.0.1 is used as the loop back address. This means that it is used by the host computer to
send a message back to itself. It is commonly used for troubleshooting and network testing.

Class B- Class B is used for medium-sized networks. A good example is a large college campus. IP addresses with a first octet from 128 to 191 are part of this class. Class B addresses also include the second octet as part of the Net identifier. The other two octets are used to identify each host. This means that there are 16,384(2 raised to 14) Class B networks each with 65, 534 (2 raised to 16-2) possible hosts for a total of 1,073,741,824(230) unique IP addresses. Class B networks make up a quarter of the total available IP addresses. Class B networks have a first bit value of 1 and a second bit value of 0 in the first octet.

Net Host or Node
145.24 53.107

Class C- Class C addresses are commonly used for small to mid-size businesses. IP addresses with a first octet from 192 to 223 are part of this class. Class C addresses also include the second and third octets as part of the Net identifier. The last octet is used to identify each host. This means that there are 2,097,152(2 raised to 21) Class C networks each with 254 (2 raised to 8-2) possible hosts for a total of 536,870,912 (2 raised to 29) unique IP addresses. Class C Networks make up an eighth of the total available IP addresses. Class C networks have a first bit value of 1, second bit value of 1 and a third bit value of 0 in the first octet.

Net Host or Node
195.24.53 107

Class E- Class E is used for experimental purposes only. Like Class D, it is different from the first three classes. It has a first bit value of 1, second bit value of 1, third bit value of 1 and fourth bit value of 1. The other 28 bits are used to identify the group of computers the multicast message is intended for. Class E accounts 1/16th (268,435,456,or 2 raised to 28) of the available IP addresses.

Net Host or Node
240 24.53.107
Broadcast- Message that are intended for all computers on a network are sent as broadcasts. These messages always use IP address 255.255.255

Q. What are the advantages of having e-commerce over extranets?

Extranets are about “ joining up” the supply chain-suppliers, resellers, distributors, customers, etc.-enabling business-to business eCommerce and streamlining production and sales process, e.g. through on-line ordering, order tracking and inventory management, and so can dramatically reduce costs in these areas. Business-to-business sales are expected to outstrip business-to-consumer sales as an Internet growth area.

The advantages and benefits to businesses include: Less Paperwork- with documents and business processes on an Extranet, information and documents can be accessed, processed, downloaded (and if necessary printed out) on demand;

Lower Costs- reduction in need for costly meetings, ‘phone calls and travel; A single interface-the Web browser is the only interface required between you and your business partners, regardless of the computer systems being used; Easy to use- Web browsers provide an intuitive, point-and-click interface Up-to-date and timely information-Web-based documents can be updated easily, giving you and your business partners faster access to accurate information.

More efficient customer service- information, such as inventory levels, is easily accessible and available 24 hours a day, 7 days a week… in effect creating self-service customers. Easy access-because Extranets use Internet technologies, information can be accessed from anywhere in the world, e.g. from a remote office.

Q. What is electronic cash? What are the properties of electronic cash?

E-cash is a cash which is represented by two models. One is the on-line form of e-cash which allows for the completion of all types of internet transactions. The other is off-line; essentially a digitially encoded card that could be used for many of the same transactions as cash.

Properties :
1. Monetary Value : Monetary value must be backed by either cash, bank – authorized credit cards or bank certified cashier’s cheque.
2. Interoperability : E-cash must be interoperable i.e exchangeable for other e-cash, paper cash, goods or services etc.
3. Retrievability : E-cash must be storable and retrievable.
4. Security : E-cash should not be easy to copy or tamper.