Some services or processes have conventionally assigned permanent port numbers. These are called well-known port numbers. In other cases, a port number is assigned temporarily (for the duration of the request and its completion) from a range of assigned port numbers.

The well-known port numbers are the port numbers that are reserved for assignment by the Internet Corporation for Assigned Names and Numbers (ICANN) for use by the application end points that communicate using the Internet's Transmission Control Protocol (TCP) or the User Datagram Protocol (UDP). Each kind of application has a designated port number. For example:

• File Transfer Protocol (FTP) application has the port number of 21;
• Domain Name Service (DNS) application has the port number of 53;
• Hypertext Transfer Protocol (HTTP) application has the port number of 80;
• Post Office Protocol Version 3 (POP3) application, commonly used for email delivery, has the port number of 110.

When one application communicates with another application at a host computer on the Internet, it specifies that application in each data transmission by using its port number.

The well-known ports cover the range of possible port numbers from 0 through 1023.They can only be used by a system process or by a program run by a privileged user. The registered ports are numbered from 1024 through 49151. The remaining ports, referred to as dynamic ports or private ports, are numbered from 49152 through 65535.

Every device connected to the Internet must have a unique IP address for identification. Besides the IP address, a port number is associated, but usually implicitly. A port number is a way to identify a specific process to which a network message is being forwarded when it arrives at a server. In other words, we use the IP address to identify a server, and the port number to identify the service provided by the server. For the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP), a port number is a 16-bit integer (0 - 65535) that is put in the header of a message unit. This port number is passed logically between client and server transport layers.

For example, a request from your Web browser to a remote Web server may request a Hypertext Markup Language (HTML) document. Such requests are served by the Hypertext Transfer Protocol (HTTP) process which is running on the remote server. In order to pass your request to the HTTP process in the remote server, the TCP software layer in your computer identifies the port number of 80 (which by convention is associated with an HTTP request) that is appended to your request. At the server end, the TCP layer will read the port number of 80 and forward your request to the HTTP service at the server.

UMTS is the acronym for Universal Mobile Telecommunications Service. It offers a consistent set of services to mobile computer users and mobile phone users, no matter where they are located in the world. UMTS is a so-called third-generation (3G) technology. It provides broadband, packet-based transmission of text, digitized voice, video, and multimedia at data rates up to 2 megabits per second (Mbps). UMTS is based on the Global System for Mobile Communication standard (GSM), endorsed by major standard bodies and manufacturers. Once UMTS is fully implemented, computer and phone users can be constantly attached to the Internet as they travel. They will have the same set of capabilities regardless of where they are in the world.

The higher bandwidth of UMTS can also provide new services, like video conferencing. UMTS realizes the Virtual Home Environment (VHE) in which roaming users can have the same computing environment on the road as they have in their homes or corporate computing environment. VHE is part of IMT-2000 and UMTS. With VHE, a foreign network emulates the behavior of the user's home network. When users roam to foreign networks, they can still have the same services that they are accustomed to at their home network.

3G will keep people connected at all times in all places, even in aircraft and space stations. Major features provided by 3G are:

• Support all popular voice and data modes (such as cellular telephone, fax, paging, email, video conferencing, and Web browsing)
• Packet-based transmission of text, digitized voice, video
• Enhanced multimedia (including voice, data, video)
• Broadband Internet connection with high speed (up of 2 Mbps)
• Always-on data connection
• Operation at about 2 GHz transmit and receive frequencies
• Enhanced roaming capability among different 3G systems around the world (such as CDMA-2000 and W-CDMA)

The data transmission speed of 3G is 144Kbps in a high-speed moving environment, as compared to only 40Kbps provided by 2.5G. In a low-speed moving environment, speed is 384Kbps. Speed can be up to 2Mbps in a stationary environment. Such high speed enables transmission of large-scale data, digital photos, video and software downloading.

3G is the acronym of third generation mobile communication. Japan is the first country to launch 3G service in 2001. This technology is expected to be mature in the near future, between year 2003 and 2005.

The third generation, as its name suggests, follows the first generation (1G) and second generation (2G) in mobile communication. The 1G period began in the late 1970s and lasted through the 1980s. These systems featured the first true mobile phone systems, known as Advanced Mobile Phone Service (AMPS). These networks used analog voice signaling, and no data service is available. The 2G phase began in the 1990s, and much of this technology is still in use today. The 2G cell phone features digital voice encoding and low-speed data connection. Examples include CDMA, TDMA, and GSM. 2G technology has steadily improved, with increased bandwidth, packet routing, and the introduction of multimedia. The present state of mobile communication is often called 2.5G or GPRS.

3G services, in simple terms, feature enhanced roaming, broadband always-on mobile access with Internet Protocol (IP)-based services, video and multimedia services. Examples include Wide-band CDMA and CDMA-2000.

Internet Roaming Service works in the following way:

1. The Internet user must already subscribe to an ISP that offers roaming service arrangements, e.g. an ISP in Hong Kong. This ISP is known as the home ISP.
   
   
2. The user can determine a cooperating ISP in a city to which the user is travelling. e.g. an ISP in Beijing, China. Information of a cooperating ISP or point-of-presence (POP) is available from the home ISP.
   
   
3. In the travel location, the user can call the local ISP's designated phone number through a computer modem, entering information during login that will identify the user's home ISP.
   
   
4. The "foreign" ISP will contact the home ISP and determine that the user is a valid user.
   
   
5. After successful authentication by the home ISP, the "foreign" ISP will grant the user access to the Internet. The user will be able to browse the Internet and to access email from the home ISP's mail server.
   
   
6. The user will be charged at local telephone rates. In addition, the home ISP may levy an additional roaming usage charge for this service. In this way, the user does not need to pay for expensive long distance calls to connect to the home ISP.
   

In general, digital camera uses 2 measurements of pixel count: CCD pixels count and Effective pixels count. CCD Pixels are the total number of pixels, including the inactive pixels known as Video Signal Shading. Effective pixels are the true pixel count in lesser amount than the CCD pixels count. Normally, it is the effective pixel count which matters on a digital camera.

The inactive pixels are located at some of the vertical columns and horizontal rows on the edges of sensor and covered by a black dye, for a digital camera to know "what black is" it needs to take a "dark current" reading.

It is noteworthy that digital camera manufacturer usually uses the CCD pixels count more than the effective pixels count. A good example of this is Minolta DiMAGE 7 which uses 5.24 megapixels but its effective pixels count is 4.92 megapixels (2560x1920). You should pay more attention on this part to purchase any digital camera.


What are Pixel & Resolution?

Pixel is the short form of picture element, usually expressed in terms of square shape (Fujufilm is now using hexagonal-pixel), defined as the basic unit of programming color and intensity in a digital picture. Pictures are divided by thousands of pixels (small dots), arranged in rows and columns. The pixels are so close together that they appear connected.

Most digital camera manufacturers use the total number of pixels of the sensor used as an indication of the camera's resolution. The physical size of a pixel depends on how you've set the resolution and output image size. Resolution is the number of pixels that can be displayed or output, expressed in terms of the number of pixels on the horizontal axis and the number of vertical axis (e.g., 1024 x 768, 800 x 600).

If the image capturing (CCD sensor) works properly, the color and intensity (brightness) for each pixel will be consistent with those of true picture.

In principal, the more the CCD pixels count, the higher the resolution, and the more detail the digital image. However, you need to pay the higher price for digital camera with higher CCD-pixel count. Think clearly about your own need before determining the number of pixels of the digital camera you want. Below is the related reference:

As long as you opt for email sharing, personal webpage development or Snap Shot, a digital camera with 6 megapixels such as Contax Digital is not essential. On the contrary, if you use for salon photo or promotional purpose, the digital camera with 5-6 megapixels is indispensable. The 3-4 megapixels' digital camera can play a balance between the factors of price and picture quality.

Internet Roaming is the ability to get access to the Internet when you are away from your home city or country at the price of a local call or at a charge considerably less than the regular long-distance charges. For example, if you normally get access to the Internet from an access provider in Hong Kong and are travelling to Beijing, China, you can call a designated access provider in Beijing, China. Instead of paying long distance charges to your local provider in Hong Kong, you pay the local phone connection charge in Beijing, China and a modest additional charge for the roaming service.

Internet Roaming Service is made possible through Internet Service Providers (ISPs) who have cooperative agreements to grant each others customers local access to the Internet. Special software allows cooperating ISPs to keep track of and calculate prearranged payments for usage differences. There are some global Internet roaming providers (e.g. iPass, GRIC, AT&T, IBM) who have agreements with ISPs around the world. It forms an alliance for low-cost global communications. The alliance will have many access points or Point-Of-Presence (POP) in different countries. The global Internet roaming provider will provide the centralized service of usage settlement and clearinghouse function among partner ISPs.

The most obvious improvement of IPv6 over IPv4 is that IP addresses are lengthened from 32 bits to 128 bits. This extension anticipates considerable future growth of the Internet and provides relief for the shortage of network addresses.

IPv6 describes rules for three types of addressing:

• unicast (one host to one other host),
  
• anycast (one host to the nearest of multiple hosts), and
• multicast (one host to multiple hosts).

Additional advantages of IPv6 are:

• Options are specified in an extension to the header that is examined only at the destination, thus speeding up overall network performance.
• The introduction of an "anycast" address provides the possibility of sending a message to the nearest of several possible gateway hosts with the idea that any one of them can manage the forwarding of the packet to others. Anycast messages can be used to update routing tables along the line.
• Packets can be identified as belonging to a particular "flow" so that packets that are part of a multimedia presentation that needs to arrive in "real time" can be provided a higher quality-of-service relative to other customers.

The IPv6 header now includes extensions that allow a packet to specify a mechanism for authenticating its origin, for ensuring data integrity and privacy.

Internet Protocol Version 6 (IPv6) is the latest version of the Internet Protocol (IP). It is also called Next Generation Internet Protocol or IPng. It is now included as part of IP support in many products including major computer operating systems. Formally speaking, IPv6 is a set of specifications from the Internet Engineering Task Force (IETF).

IPv6 is designed as an evolutionary set of improvements to the current IP Version 4 (IPv4). It is a natural increment to IPv4. It can be installed as a normal software upgrade in Internet devices and is interoperable with the current IPv4. Network hosts and intermediate nodes with either IPv4 or IPv6 can handle packets formatted for either version of the Internet Protocol. Users and service providers can upgrade to IPv6 independently without having to coordinate with each other.

IPv6 is designed to run well on high performance networks (e.g. Gigabit Ethernet, SONET, ATM, etc.) and at the same time still be efficient for low bandwidth networks (e.g. wireless). In addition, it provides a platform for new Internet functionality that will be required in the near future.

VoIP (Voice over IP - that is, voice delivered using the Internet Protocol) is a term used in IP telephony for a set of facilities to manage the delivery of voice information using the Internet Protocol (IP). In general, this means sending voice information in digital form in discrete packets rather than in the traditional circuit-committed protocols of the Public Switched Telephone Network (PSTN). A major advantage of VoIP and Internet telephony is that it is free of charge.

The general term VoIP is derived from the VoIP Forum - a forum formed by major equipment providers, including Cisco, VocalTec, and 3Com to promote the use of ITU-T H.323, the standard for sending voice (audio) and video using IP on the public Internet and within an intranet. The Forum also promotes the use of directory service standards (for locating other users) and the use of touch-tone signals for automatic call-distribution and voice mail.

In addition to IP, VoIP uses Real-Time Protocol (RTP) to help ensure that packets get delivered in a timely way. Using public networks, it is currently difficult to guarantee quality of service. Better service is possible with private networks managed by an enterprise or by an Internet Telephony Service Provider.

PSTN (Public Switched Telephone Network) is the world's collection of interconnected voice-oriented public telephone networks. It's also referred to as the Plain Old Telephone Service (POTS). It's the aggregation of circuit-switching telephone networks that has evolved from the days of Alexander Graham Bell. Today, it is almost entirely digital in technology, except for the final link from the telephone company central office to the user.

Internet users can connect to their Internet Service Provider (ISP) through PSTN by using an analog dialup modem. The download rate is up to 56,000 kilobits per second (kbps). ISPs need to pay the PSTN service provider for access to its infrastructure and share the circuits among many users through packet-switching. In Hong Kong, this is called Public Non-Exclusive Telecommunications Services (PNETS) charge and is usually charged to ISP subscribers.

POTS is a term sometimes used in discussion of new telephone technologies in which the question of whether and how existing voice transmission for ordinary phone communication can be accommodated. For example, Asymmetric Digital Subscriber Line (ADSL) and Integrated Services Digital Network (ISDN) connections provide some parts of their channels for "Plain Old Telephone Service" while providing most of their bandwidth for digital data transmission.

The following steps will be run in SET to ensure a secure shopping:

1. The customer opens a Mastercard or Visa bank account. Any issuer of a
   credit card is some kind of bank.
2. The customer receives a digital certificate. This electronic file functions as a credit card for online purchases or other transactions. It includes a public key with an expiration date. It has been through a digital switch to the bank to ensure its validity.
3. Third-party merchants also receive certificates from the bank. These
   certificates include the merchant's public key and the bank's public key.
   
4. The customer places an order over a Web page, by phone, or some other means.
   
5. The customer's browser receives and confirms from the merchant's
   certificate that the merchant is valid.
   
6. The browser sends the order information. This message is encrypted with the merchant's public key, the payment information, which is encrypted with the bank's public key (which can't be read by the merchant), and information that ensures the payment can only be used with this particular order.
   
7. The merchant verifies the customer by checking the digital signature on the customer's certificate. This may be done by referring the certificate to the bank or to a third-party verifier.
   
8. The merchant sends the order message along to the bank. This includes
   the bank's public key, the customer's payment information (which the
   merchant can't decode), and the merchant's certificate.
   
9. The bank verifies the merchant and the message. The bank uses the
   digital signature on the certificate with the message and verifies the
   payment part of the message. The bank digitally signs and sends
   authorization to the merchant, who can then fill the order.

SET (Secure Electronic Transaction) is a system for ensuring the security of financial transactions on the Internet. It was supported initially and popular used by Visa, Mastercard, Microsoft, Netscape, and others. With SET, a user is given an electronic wallet (digital certificate) and a transaction is conducted and verified using a combination of digital certificates and digital signatures among the purchaser, a merchant, and the purchaser's bank in a way that ensures privacy and confidentiality. SET makes use of Netscape's Secure Sockets Layer (SSL), Microsoft's Secure Transaction Technology (STT), and Terisa System's Secure Hypertext Transfer Protocol (S-HTTP). SET uses some but not all aspects of a public key infrastructure (PKI).

As a customer wants to use SET, he/she must has a SET-enabled browser such as Netscape or Microsoft's Internet Explorer and that the transaction provider (bank, store, etc.) has a SET-enabled server. Hongkong Bank is one of a SET provider in Hong Kong.

S-HTTP (Secure HTTP) is an extension to the Hypertext Transfer Protocol (HTTP) that allows the secure exchange of files on the World Wide Web. Each S-HTTP file is either encrypted, contains a digital certificate, or both. For a given document, S-HTTP is an alternative to another well-known security protocol, Secure Sockets Layer (SSL). S-HTTP is easily confused with HTTPS (HTTP over SSL). A major difference is that S-HTTP allows the client to send a certificate to authenticate the user whereas, using SSL, only the server can be authenticated. S-HTTP is more likely to be used in situations where the server represents a bank and requires authentication from the user that is more secure than a userid and password.

S-HTTP does not use any single encryption system, but it does support the Rivest-Shamir-Adleman(RSA) public key infrastructure encryption system. SSL works at a program layer slightly higher than the Transmission Control Protocol (TCP) level. S-HTTP works at the even higher level of the HTTP application. Both security protocols are supported by many popular web browsers, but they can be only used with a given document.

SSL (Secure Sockets Layer) is a commonly used protocol for managing the security of a message transmission on the Internet. SSL uses a program layer located between the Internet's Hypertext Transfer Protocol (HTTP) and Transport Control Protocol (TCP) layers. The "sockets" part of the term, SSL, refers to the sockets method of passing data back and forth between a client and a server program in a network or between program layers in the same computer.

SSL is included as part of both the Microsoft and Netscape browsers and most Web server products. SSL was developed by Netscape and is now supported by Microsoft and other Internet client/server developers as well. If a Web site is on a server that supports SSL, SSL can be enabled and specific Web pages can be identified as requiring SSL access. SSL is an alternative to another commonly used security protocol, S-HTTP. Newer browsers support both SSL and S-HTTP. Currently a de facto standard, SSL has been submitted to the Internet Engineering Task Force (IETF) as a proposed official standard.

Bluetooth is a kind of wireless technology for communication among computers, electronic devices and telecommunication devices. Basically, it uses a piece of chip module for radio transmission, reception and all other operations. It works in the 2.45GHz unlicensed radio frequency band. It facilitates fast and secure transmission of both voice and data.

Bluetooth can transmit information within a distance of 10m to 100m depending on the transmission power and application. It provides a high transmission rate up to 1Mbps. Bluetooth uses a Packet Switching Protocol, which based on a frequency hop scheme with 1600 hops/s. All data are protected by advanced error detection and correction methods, as well as encryption and authentication routines for the user's privacy.

Bluetooth have three different classes, designed for different applications:-

If you would like to learn more about Bluetooth, please visit its official website at http://www.bluetooth.com.

A Wireless LAN is a Local Area Network (LAN) that transmits over the air. It does not require any cable to line up devices. Nor does it restrict to line of sight transmission like InfraRed devices (IrDA). Wireless access points (or base stations) are connected to an Ethernet hub and transmit a radio frequency over an area of several hundred feet. These radio waves can penetrate walls and other non-metal barriers.

In June 1997, the Institute of Electrical and Electronics Engineers, Inc. (IEEE) 802.11 committee established a Wireless LAN protocol. It specifies an standard interface between a wireless client and a base station or access point, as well as among wireless clients. In 1999, newer standards 802.11a and 802.11b support higher data transfer rate. Nowadays, most devices comply with the IEEE 802.11b standard. It supports data rate up to 11Mbps in 2.4GHz unlicensed frequency band.

Laptops and PDAs use wireless LAN cards in PCMCIA interface, while stand-alone desktops use plug-in ISA/PCI wireless LAN cards or plug-in ISA/PCI adapter cards to suit wireless LAN card in PCMCIA interface. Wireless LANs function like cellular phone systems. Each access point is a base station that transmits over a radius of several hundred feet. In systems designed for office use, users can seamlessly roam between access points without dropping the connection. Wireless LAN can serve an individual connecting a laptop or PDA to desktop machines, servers and backend broadband infrastructure.

MPEG-4 is a multimedia standard combining communication and entertainment, such as Video Phone, Video Email and Electronic News. It was designed from the group up to work over low bandwidth, high bit error rate networks (i.e., wireless) and, from the get-go, with interoperability and scalability in mind. The MPEG-4 standard allows companies develop compatible multimedia compression solutions to ensure competition amongst vendors and lower prices. Companies can be fully compliant and interoperable while offering enhancement to differentiate their solutions.

As an example, scalability allows a content provider to encode a file once and deliver that same file to a desktop user at 384Kbps and a mobile wireless user over a network at 64Kbps.

To use MPEG video files, you will need a multimedia personal computer and an MPEG viewer or client software that plays the typically large MPEG files (which has a file name suffix of .mpg) You can download shareware or commercial MPEG players from a number of sites on the Web. (Note that .mp3 file suffixes indicate MP3. MPEG-1 audio layer-3) files, not MPEG-3 standard files.)

http://www.iysoft.net/mplayer.htm

MPEG (pronounced EHM-pehg), the Moving Picture Experts Group has been developing standards for digital video and digital audio compression since 1988. It operates under the auspices of the ITU (International Telecommunications Union) and ISO (International Standards Organization). The MPEG standards are an evolving series, each designed for a different purpose.

The developers of MPEG targeted for four format originally, MPEG-1~MPEG-4, in order to meet the requirements for different bandwidths and digital qualities. However, MPEG-3 had become obsolete thus we are left with only 3 format. In general, MPEG has three advantages over other compression and de-compression solutions. Firstly, it has been developed as an international standard, rendering a very high compatibility rate. Secondly, it has a relatively higher compression rate, reaching a maximum of 200:1. Thirdly, the data loss level remains low at high compression rates.

http://www.iysoft.net/mplayer.htm

Ever imagined making a telephone call without a telephone handset? It is now possible to long distance calls through the Internet. You can choose to make either a PC-to-PC or PC-to-phone call and there is no need to use a handset at all.

All you will need is a computer with Internet access, a microphone and a speaker. Simply connect to the Internet, visit an Internet phone web-site, such as http://www.mediaring.com/, http://www.vocaltec.com/iptelephony/iptel.htm/, or http://www.pulver.com/fwd/, follow the instructions and chat away real time with your friends abroad. The call receiving party doesn't even have to own a computer as it is possible to make PC-to-phone calls. Some of the companies are offering free trail services to subscribers.

In addition to staying in touch with people abroad or while you are abroad, making long distance calls via the Internet is also a money saving option.

This issue we will take a look at how Digital Signature, Digital Certificate and Certification Authorities work together to ensure online security.

Digital Signature is an electronic document attesting to the binding of a public key to an individual or entity. It allows verification of the claim that a specific public key belongs to a specific individual. A certificate is issued and digitally signed by a trusted third party or Certification Authority.

A block of data which is generated using some secret/private key, and only the corresponding public key can be used to verify that this block of data was really created by that private key. Digital signature is usually used to verify whether a message really comes from the claimed originator, and simultaneously guarantees the integrity of the message.

Digital Certificates is an electronic certificate storing data for owner identity verification. The certificate usually contains information such as user's public key, name and email address.

Certification Authorities serves as trusted third parties to ensure trust and security in electronic transactions. They issue digital certificates to their subscribers which contain the public keys of the subscribers. Through the use of public/private key pairs and digital certificates, individuals and business can:

1. Enable the identity of the opposite party in electronic transactions.
2. Ensure the integrity and confidentiality of electronic messages transmitted over open communications networks.
3. Safeguard the non-repudiation of electronic transactions.

Source: http://www.info.gov.hk/itsd/secure/eglossary.htm

The Smart ID Card and digital identity have been recent heated topics for discussion but, what is a smart card?

A smart card is a credit card sized plastic card with an integrated circuit or 'chip' which stores and processes data electronically. Smart card technology development dates back some 20 years and has grown to become widely accepted in recent years. In 1999, 1,400 million smart cards were issued globally and in 2000, the number grew to 1,750 million.

In Smart ID Cards, the chip will carry your personal information, your photograph and your thumbprints (in data format which cannot be tampered to "reconstruct" your thumbprints). For non-permanent residents, information on conditions of stay will also be included in the smart chip.

Other possible non-immigration value-added applications include driver's licence, library card, digital certificates etc. In most cases, the card holder will be able to decide whether to include these applications in their smart identity cards.

Source: http://info.gov.hk/immd/english/idcard/idcard.htm#2

Continuing from the previous issue, we will talk about the things to note when using a PDA in this issue. Always check with your company's Network Administrator before hand for possible restrictions on remote access to the company's VPN (Virtual Private Network). You should choose the connection with encryption especially when you are working on email or web-based credit transactions.

When dealing with multimedia on PDA, always check to ensure that the hardware has sufficient resources for support. Web pages with plug-ins and streaming demand a lot of memory. Software compatibility and convertibility is also important. Always check to ensure that you are able to convert files that can be read by your PDA.

Looking ahead, technology is heading towards PDA mobile handsets and wireless access through either the mobile phone or the wireless MODEM/ LAN card and working at BROADBAND speeds.

As mobile handsets move into a 3^rd generation of technology, PDA's (Personal Digital Assistant) importance as a mobile client booms alongside the mobile handset path. PDAs have evolved from a piece of electronic calendar and phone directory to an enhanced piece of slim, lightweight handheld equipment that compliments the mobile phone. Data synchronization has enabled cross-platform compatibility (phone/ PDA/ PC) and its many functions come either pre-installed or can easily be downloaded from the Internet.

There are two main types of PDA available in the market now. The first operates on Palm and the second operates on Windows CE. Both platforms provide easy access to the Internet through 9.6Kbps to 56Kbps dial-up MODEM. To access intranets at speeds between 10BaseT to 100BaseTX, simply add a LAN card to the PDA.

User can also choose between wired or wireless MODEM access. Wireless access requires an infrared port on each the PDA and the mobile phone.

While we mine the Internet for free information and resources, we have to pay particular attention to how we will use the information and resources. Like most hardcopy materials, information and resources on the Internet are often copyrighted. If we are not careful with how we use the information, we could be breaching material copyright.
Following is a list of items that are easily accessible from the Internet but the unauthorized use of which may infringe copyright:

1. Literary Works such as books, essays, magazines and newspapers
2. Sound Recordings: conferences and broadcasts
3. Artistic Works: artwork, paintings and films
4. Musical Works: songs and compositions

It is also important to note that unauthorized use of an excerpt of these materials could be considered copyright infringement as well.

In Hong Kong, an estimated 40% of the population are Internet users, taking advantage of the accessibility and flexibility that the web has to offer as a communication tool and a source of information. As the Internet and its usage become more sophisticated, it brings about the question of Intellectual Property Rights on the Internet. Are users observing and respecting Intellectual Property Rights on the Internet, or are they not aware of such Rights at all?

It is also very easy to violate Intellectual Property Rights on the Internet. The Internet is one worldwide network platform on which one can readily go online at any time to print, download, upload, transfer, retrieve or broadcast any information and software without first clearly identifying the source of information. And one can spread information along the grapevine at great speeds and anonymously too, making it very difficult to trace the line of information flow.

The Evolution of Digital Signature

In the conventional business world, hard copies, watermarks, letter heads, sealed envelops and personal contacts are recognized as reliable to authenticate the source of our information.

In the early stages of "going digital", we have tried to mimic the hard copy based world by attempting to protect the medium through which information are conveyed. We have Local Area Network (LAN) and Wide Area Network (WAN) within our organizations and we also have Value Added Network, T1 and Lease Lines and the commonly used Internet for communications with external parties.

Internet usage is becoming popular in the Government, business and private sectors as a source for information, goods and services. With the advent of public key cryptography and legal recognition of digital signatures, the full potential of the internet is yet to be discovered. An adequate security and an appropriate legal and service infrastructure is being developed, slowly enabling the internet to become a Global Area Network (GAN) that allows real-time electronic transactions that are reliable, traceable and enforceable.

Encryption Technique

Cryptography ensures confidentiality by encrypting a message using a secret key in association with an algorithm to provide a "scrambled" version of the message that the recipient can decrypt, using the original key for content retrieval. The key must be kept secret between the two parties. The irony, however, is these keys are usually managed and kept secret by cryptographic applications.

Public key cryptography solves this problem by replacing the secret key with a pair of key - one private and one public. The encryption is usually done by a digital signature software or downloaded from a browser. One of the pair of keys (the public key) is generated and is released to the online world, using any identity the user chooses. This scenario underscores the need for an entity to serve as a trusted third party, known as CA, to vouch for individual's identities and their relationship to their public keys.

*The CA is a trusted third party that issues digital certificates to its subscribers, binding their identities to the key pairs they use to digitally sign electronic communications.

Narrowband transmission refers to access lower than 1.5Mbps. Broadband covers 1.5Mbps or above.

Simply put, broadband's transmission capacity is higher than narrowband. So performance is better when surfing the web or downloading a file.

Narrow band transmission uses traditional 56k dial-up modems. A free serial port/USB connection to a "Dial-up" modem or one "internal modem card" is required.

A FTTB converter or ADSL modem - with a PCI Ethernet card are required for broadband access

IWe are going to introduce 2 technology deployment to access internet:

Asymmetric Digital Subscriber Line - (ADSL). It carries the telephone signal into the home and can also be used for high-speed data transmission. ADSL is a popular and key factor for high-speed Internet access. Both North America and Europe are in the process of DSL deployment.

Fibre To The Building (FTTB) is another technology using direct optical fibre connected from telephone exchanges to a customer building. An Optical Network Unit (ONU) is located in the building, handling 40 customers at a time. The ONU connects high speed data from users to the Internet world via ATM networks.