Computer Network Security

The computer network security is a key issue to promote the development of trade in all areas. One word ‘security’ covers many different aspects, both technical, organizational and legal. Latitude users against security problems is often irrational, which does not help to simplify the discussion. The safety of paying by credit card over the Internet is part of controversial topics. In 1996 our experimental platform Infoway, we asked our 10,000 users to pay a participation fee for access. All means of payment were available on the server from the secure online credit card, send the card number by fax or check. Contrary to popular belief, approximately 60% of users chose the secure online payment, 30% and 10% check preferred to send the credit card number by fax which even provided a PIN! The perception of safety is an important element to consider in developing these systems.

From a technical perspective, safety covers both access to information on workstations, servers and network data transport. In this short paper, we focus on the problems of information security in trade through public or private networks. Internet, the network of networks, is a tool that allows all computers regardless of their type to communicate with each other. Technology (TCP / IP) has simplified the creation of networks, thus reducing the cost of telecommunications. However, the security features are not addressed by this protocol.

Giant Microsoft Will Buy the Phone Service Skype f...

Software giant Microsoft has announced today that it agreed to buy the online telephony service Skype for $ 8.5 billion $ U.S., its largest acquisition in 36 years of history.

The acquisition of Skype would offer Microsoft a potentially valuable tool for communication while the firm tries to increase its presence on the Internet and the smart phone market.

Skype is particularly held by the website and eBay auction fund Silver Lake. The service has 663 million users worldwide.

Microsoft wants to marry the functions of Skype with its Xbox game console, the mail program Outlook and Windows smartphones.

About 170 million people use Skype’s services each month. They spent over 207 billion minutes of voice and video communications in 2010.

Entrepreneurs Niklas Zennstrom and Janus Friis, who started the company in 2003, have struggled to make their business profitable since most people use Skype calling services for free. Approximately 8.8 million customers per month, only 5 percent of the total number of users pay for services.

The group would have lost $ 7 million last year for a turnover of U.S. $ 860 million. End of 2010, its long-term debt was U.S. $ 544 million.

The current CEO of Skype Tony Bates retain the head of the company.

Microsoft makes its biggest acquisition so, after the takeover in 2007 of technology providers for digital marketing Aquantive approximately U.S. $ 6 billion.

The site eBay acquired Skype in 2005 for U.S. $ 2.6 billion, but he never managed to combine phone service and bids.

He had sold 70 percent of its shares to an investor group led by Silver Lake funds Horowitz and Andreessen to U.S. $ 2 billion 18 months ago.

Wi-Fi Is It Dangerous to The Health of Children?

This topic is not directly subject to the site. However, I am asked more often the question: Wi-Fi or mobile phone are dangerous to health especially children?

So I decided to address this issue by providing the scientific facts that will help you form an opinion. It is impossible to prove that a particular product is not dangerous. However, it is possible to measure the effects and to deduce levels of risk.

The common feature of Wi-Fi or mobile phone is to receive and emit radio waves. This is not new since radio, television and most telecommunications systems use these waves for a hundred years. What is new is the proliferation of these devices that are installed by tens of millions of users nearby. To assess the level of dangerousness, we must understand the nature of radio waves or radio frequency (RF) and their action on the human body.

Small breviary radio waves or radio frequency (RF)

Radio waves or radio frequency (RF) are created by the movement of electrical charges in antennas. These waves consist of an electric field and magnetic fields that radiate into space from the antenna. Their propagation speed is the speed of light. What differentiates the waves is their frequency-the number of cycles per second wave-which we can deduce the wavelength of the light-speed divided by frequency, which is the distance traveled by a wave. Frequency expressed in Hz (hertz), kHz, MHz (1 million) or GHz (one billion). To give current values, the frequencies of FM radio stations are between 88 and 108 MHz, television between 300 and 600 MHz, the mobile phone 900 or 1800 MHz and 2400 MHz Wi-Fi (2.4GHz).

Intranet: For What Services?

The introduction of the Intranet within the company allows both to install new applications quickly and increase the capabilities of existing applications by making them communicate. The new possibilities offered by the intranet within the company are many. Improving communication, the sharing of geographically dispersed resources to accomplish a task, the possibility of combining both a local presence by taking advantage of access to global expertise of the company, the creation of virtual teams without increasing overheads, the ability to provide service 24 hours a day 24 a new beginning each time in the world.

The first services to implement an Intranet are naturally those who have made the success of the public Internet and the first email. A recent survey by Gartner Group survey of 500 companies provided the top 5 applications Intranet:

1. Email
2. Access to public Internet
3. Access to corporate data
4. The distribution and publication of information
5. Records management.

The installation of an e-mail or connecting the local mail with the rest of the world via the Internet is the operation priority. The savings are immediate. An electronic message is from three to ten times cheaper than a fax in the distance. Its asynchronous nature, email adapts to jetlag. Attachments of all types reduce photocopying and allow modification and reuse of materials. One constraint: it must be used personally.

The establishment of an intranet with email is inseparable from the constitution and the provision of all a business directory that maintains information about employees, services or applications available and the controls of access. Such directory services are available on the network. Users will find information such as phone numbers and email addresses. Administrators manage access to services, applications also have direct access to this information. These directories, when they existed, were closed and proprietary. A recent standard (LDAP) directory will allow them to communicate and to exchange electronic business cards.

Understanding IPv6

An IPv6 address is much longer than IPv4 address. This is one reason to use the new protocol. The number of addresses is virtually infinite. Each machine (node ​​in IPv6 terminology) connected to the network can use a global IPv6 address or addresses. No more complications NAT and port forwarding. Again all the machines can communicate directly.

An IPv6 address is represented by 128 bits (32 in IPv4) that is written in 8 suites with 4 hexadecimal characters (0-9, af) separated by colons:

2a01: 05d8: 52eb: be1d: F053: 2abf: ef7d: 6c89

The notation of IPv6 addresses

The notation has 39 characters. It can be simplified by removing the leading zeros and replacing a sequence of zero. The following addresses are all equivalent.

2001:0 db8: ab 0000:0000:0000:0000:1428:57
2001:0 db8: 0000:0000:0000:: 1428:57 ab
2001:0 db8: ab 0:0:0:0:1428:57
2001:0 db8: 0:0:: 1428:57 ab
2001:0 db8:: 1428:57 ab
2001: db8:: 1428:57 ab

Addresses 2001: db8:: / 32 as above are used for examples and are not routed.
URL notation

IPv6 addresses in URLs are written in [] that adds a port number if necessary.

http:// [2a01: 5d8: 52eb: be1d: F053: 2abf: ef7d: 6c89]: 81 /

Scoring Network

This is the CIDR format that is used in IPv6. It shows the number of bits that are identical in all places of the network. Example
2a01: 5d8: 52eb:: / 48 represents the network address range from which
2a01: 5d8: 52eb: 0:0:0:0:0 to
2a01: 5d8: 52eb: ffff: ffff: ffff: ffff: ffff

This is different from the concept of class used in IPv4. The goal is to simplify the routing tables.