Posts Tagged ‘Network’

DES and 3DES

Tuesday, July 14th, 2009

Data Encryption Standard (DES) data are encrypted in 64-bit blocks using a 56-bit key. The DES algorithm takes the input through a series of transformations: initial permutation; a complex function, which involves both permutation and substitution operations and depends on a key input; a simple permutation function that switches the two halves of the data; the function is applied again; and a permutation function that is the inverse of the initial permutation takes place. There are five “modes of operation” that have been defined in order to apply DES to a variety of applications. They are Electronic Codebook, Cipher Block Chaining, Cipher Feedback, Output Feedback Counter, and Counter (Cryptography Concepts, 2005).

Triple DES or 3DES involves repeating the DES algorithm three times on the plaintext, using two or three different keys to produce the ciphertext. As stated in the article DES is dead. Long live…Well, um, What, “First it encrypts, then it decrypts and finally it encrypts again” (Moskowitz, 1999). Three DES is now used because it is very resistant to cryptanalysis, serving as an alternative to add security against the potential vulnerability of DES to brute-force attack. Triple DES has been adopted for use in the key management standards ANSI X 9.17 and ISO 8732, along with a number of Internet-based applications, such as PGP and S/MIME (AES, Ciphers, and Confidentiality, 2005). The picture below shows the triple encryption process, as well as show the middle portion of 3DES as a decryption rather than an encryption making it more secure.

A nonce and key distribution center (KDC) shares a secret key or “master” key between each party on a network. The KDC is responsible for generating nonce and keys to be used for a short time over a connection between two parties, known as session keys, and for distributing those keys using the master keys to protect the distribution. The following steps occur:

1. A issues request to the KDC for a session key with B. The message includes the identity of A and B, as well as a unique identifier for the transaction, a nonce, which may include a random number or a counter.

2. The KDC replies with a message encrypted using Ka. Thus, only A can read the message and knows the message originated at the KDC. The message includes:

• The one-time session key, Ks, to be used for the session.
• The original request message, including the nonce, to enable A to match this response with the appropriate request.

In addition, the message includes two items intended for B:

• The one-time session key, Ks.
• An identifier of A, IDA.

These are encrypted with the master key that the KDC shares with B. They are sent to B to establish connection and prove A’s identity.

3. A stores the session key for use in the upcoming session and forwards to B the information that originated at the KDC for B. This information is protected from eavesdropping, because it is encrypted by the master key, Kb. B knows the session key, A’s identity, and that the information originated at the KDC.

4. B then sends a nonce, N2, to A, using a newly minted session key for encryption.

5. Using the session key, A responds with f(N2), where f is a function that performs some transformation on N2 (e.g., adding one) (Stallings, 2003 pgs 214-15).

In conclusion, the above explained how DES works, why 3DES is now used, why the middle portion of 3DES is a decryption rather than an encryption, and explain a nonce and a key distribution center.

Works Cited

Moskowitz, Robert. (1999). DES is dead. Long Live… well, um, what? Network Computing, vol. 10 issue 6. Retrieved October 22, 2005, from, EBSCO Host Research Databas

Stallings, William. (2003). Cryptography and Network Security: Principles and Practice. New Jersey: Pearson Education, Inc.

Joshua Maluchnik, M.I.T., MCP/MCTS
Account Executive
Tranztec Solutions, Inc.
http://www.tranztec.com

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Portable Solar Power Systems

Thursday, May 14th, 2009

What is a Laptop Portable Power Pack?

Laptop Portable Power pack is a kit which contains certain accessories which will act as a power charger when connected to your electronic devices. All devices such as Mobile phones, Laptops, PDAs, MP3 players can be charged in an easy plug and play manner.

Why Laptop Portable Power?
In this competitive world, work on the go is the mandate. Professionals are increasingly interested in proving their worthiness in the workplace. One of the best ways to prove it is to work anytime, anywhere. One of the greatest threats of these mobile workers is losing battery power in their mobile devices, PDAs or Laptops. This is bound to happen only at the most inappropriate of moments, losing a laptop power when you are about to close a deal, about to email a presentation etc. Fortunately, mobile workers have a variety of options for portable power.

With the advancements in the field of computing, laptop portable power has become an essential one for mobile workers as they so much depend on their systems. With the laptop portable power pack, you can charge your laptop and work with full battery for up to 96 hours!!!
How does a Laptop Portable Power Pack work?

Laptop Portable Power Pack generates power by two essential methods

  • With the help of Photovoltaic cells by utilizing the solar light energy
  • With the help of a battery inside the pack which is re-chargeable

The battery pack is just chargeable like any other electronic device. When you are all set to go, you can just carry your power pack and use it whenever you need. With a lot of effort taken for clean energy, many organisations like Google are progressing towards it. In the near future, solar power will be key thing. Moreover, our solar power pack acts like a portable power generator when placed in sunlight.

If you are a social networking geek and love nature, you definitely want to carry your laptop when you go to every place. And this Laptop Portable power pack can be a perfect companion for you on a beach where you can just fall in love with your environment and your laptop. Sounds pretty fascinating right?

Laptop portable power will become one of the essential assets of any mobile worker and will be the perfect companion for any traveler and nature lover. Even adventurers hiking in mountains would be fascinated with this pack. So, let’s start generating and consuming power wherever we go.

Portable Solar Power Systems Power your electronic devices using the power of the sun!

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The Role of a Network Consultancy

Sunday, April 19th, 2009

Whether you are setting up a new company or you are just getting ready for the next step in your business’s progression, you will find that one resource that you need to think about is a network consultancy. A network consultancy is essentially a business that gives you the most effective and advantageous network set up for your business and then after the network is set up, it will maintain it for you. The truth of the matter is that there really is an art to setting up a computer network and if you are in a place where this resource is necessary, you can get a lot of important work taken care of in one fell swoop.

The first point that you should realize when it comes to computer consultancy is that it provides you with a great deal of experience at your disposal. Computer consultancies have a great deal of stock set in how much experience they have in setting up a network that is efficient, effective and gives you the resources that you need and this is something that can take years of work to figure out. Networking may seem rather simple at first, but the truth of the matter is that there are many different resources that need to come into play at once. There are enough factors that are competing for resources that having a computer consultancy on hand is quite advantageous.

Another point that you will discover is that a computer consultancy firm can provide a great deal of relief when it comes to helping out your IT department. Your IT department has a lot going on and if you are just getting a computer network setup, you will find that the IT staffs is already going to be under a number of different stressors. Make sure that you consider what duties your IT department is already shouldering and whether adding computer networking to the mix is going to be something that they welcome. In many cases, you will find that your IT department may not even be set up for network installation and maintenance. This is not something that you want to necessarily integrate into your own staff, so consider how a network consultancy can help you.

Remember that at the end of the day, your computer networking is something that should be rock solid. In this day and age, your business can effectively grind to a halt if your computer networking goes down and this is not something that you want networking amateurs working on. With a good network consultancy firm working on your behalf, you will find that you are in a great place to move forward and to get your work taken care of. You will get the benefit of working with professionals who have a lot of experience behind them.

Networking is something quite complex and the truth is that it is growing more complex by the day. Take some time to consider the good that a networking consultancy firm can do for you and really get the most out of your business contacts.

Derek Rogers is a freelance writer who writes for a number of UK businesses. For information about IT Networks, he recommends Prodec Networks, a leading Network Supplier.

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Life is Unpredictable, Your Data Shouldn’t Be!

Saturday, April 11th, 2009

With the arrival of various internet based applications which allow people to express themselves, the web has definitely become democratic. But using the same for carrying out personal or malicious activities, and that too using your office computer can land you in deep trouble.

A senior executive at a marketing firm was accused by his boss of passing on vital company data to a competing firm, he denied it. “But we have the proof”, his boss told him and showed it to him, as clear as daylight. The executive resigned immediately. It’s a fact of life in the 21st century workplace; the boss may well be watching you, especially if you use a office computer. Improper computer use can also spell legal trouble. Downloading pirated music or movies onto a work computer can prompt a copyright-infringement suit. Viewing pornography or sending sexually suggestive emails can lead to sexual harassment claims. Thus, an employer can use special software to monitor everything – it’s as if a camera is watching your computer.

Companies are using two types of spying software: network-based programs that monitor all traffic passing through a system, and programs that sit directly on an employee’s desktop. What can such software do? They can track and block the websites a user tries to visit and log his or her every keystroke. The boss can see screen shots of what the employees do on Yahoo! He can see what they’re typing, whether it’s resumes or business-related stuff. Such program even keeps track of songs that employees download to their iPod. In the American and European countries, one in four companies reports firing someone for improper email use. Such software works without being identified, even by an anti-virus program.

There are plenty of valid reasons for companies to monitor their worker’s computer use.

1. Productivity: A recent survey found that employees on average wasted at least two hours a day-much of it online-doing things other than work.

2. Security: Porn, gambling and gaming sites, for example, can harbour viruses and other malicious programs that load onto a computer secretly and allow outsiders to damage a network or make off with sensitive information.

3. Companies also have competitive reasons to keep tabs on workers.

4. Employee attrition: With young employees who may have quickly changing loyalties, more and more companies see the need to spy.

5. Reputation Management: Companies want to be sure that there employee’s defamatory work does not harm the company’s global reputation.

Implementing all these policies may be beneficial for the companies, but the employees always feel pressurised. They feel paralysed, if their every activity from composing the weekly report to emails is tracked. And who hasn’t opened his email to find a message from a friend passing along a goofy YouTube clip or an off-colour joke. If it does get a laugh, it’s probably passed along to a few more people. And this can seriously land the employee who first circulated such content within the company.

It seems that technology will continue to creep unabashedly into the workplace. So, if you blog, forward naughty email, flirt, chat or search for a new job, just remember that it’s safest to use your own computer for any of that in the comfort of your home.

The author is a technology trainer and consultant who helps businesses build their online brand. His key passion apart from writing articles is Web 2.0 technologies and re-creating value for living. If you feel Sameer can be of any help to you, please send an email

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How to Synchronise Your Windows PC to a Time Server

Wednesday, April 8th, 2009

Do you regularly need to correct the time on your PC? The answer is probably “Yes!”. This is because computers have very poor time-keeping hardware. Often, the system clock in a regular PC can drift by minutes each day. However, help is at hand. It is very easy to synchronise the time on your Microsoft Windows computer with one of the most accurate clocks in the world. This article describes how to configure your Windows system to synchronise it’s internal system time with an Internet based ‘atomic time’ reference.

PC’s utilise an internal hardware real-time clock to maintain time. Generally, this hardware clock circuit utilises very low-cost components. This results in poor time-keeping performance. It is not unusual for a computer to loose minutes each day. There are hardware solutions available, which can improve timekeeping, such as more precision crystal oscillators. However, modifying PC’s at board level is not an option for most users. Additionally, accurate time-keeping hardware can be prohibitively expensive. Ideally, a software solution to maintain accurate time is required. This is where the Network Time Protocol (NTP) comes in.

NTP is one of the oldest Internet protocols still in regular use today. Dr David Mills of the University of Dellaware invented it over 25 years ago. He recognised the need to synchronise time critical processes across the Internet. The Network Time Protocol allows client computers to synchronise to an accurate time reference over the Internet. NTP uses the UDP (User Datagram Protocol) over IP (Internet Protocol) to request time from an accurate time reference. It then waits for and accepts a response from the server before updating it’s internal system time with the supplied reference time.

There are many NTP Servers residing on the Internet. Government or educational institutions generally maintain them. A NTP server obtains highly accurate time from an external time reference such as GPS or Radio and maintains this time internally. It then distributes the precise time to network time clients.

The latest Microsoft Windows operating systems, such as XP and Vista, incorporate a SNTP (Simple Network Time Protocol) client. This client can easily be used to synchronise to an Internet or locally based NTP server. The client is configured from the time and date properties applet in the control panel, or by double clicking on the time in the system tray. One of the time properties tabs is labelled ‘Internet time’. On this tab is a field called “Server” which accepts either the IP address or domain name of a NTP time server. Click the “Update Now” button and Windows will attempt to synchronise with the selected time reference. Ensure that the “Automatically Synchronise with an Internet Time Source” option is ticked and Windows will periodically update time from the reference automatically, thus keeping your system clock accurate.

If synchronisation fails then ensure that the supplied IP address or domain name of the NTP server is correct. Alternatively, it may be your firewall that is preventing communication with the time server. NTP operates on UDP port 123, so you must ensure that this port is left open on your firewall. The Windows firewall can be accessed from the Control Panel. To open NTP port 123, open the Windows Security Centre and select ‘Manage Security Settings for Windows Firewall’. From the Windows Firewall applet select the ‘Exceptions’ tab. Click ‘Add Port’ to add an exception to the firewall. Enter a name for the exception, such as ‘NTP port’, and port number ‘123′ and check UDP. Click OK to accept the settings. If you have a separate combined firewall and ADSL router, you may need to refer to your manufacturers documentation to find out how to open a port on the firewall.

To conclude, most computers keep extremely poor time. For many applications that rely on accurate time stamps, this can be entirely unacceptable. However, by utilising the Network Time Protocol, everyone can ensure that their computers system time is kept in sync with the most accurate clock in the world!

Please visit TimeTools website for more information and articles on NTP servers, network time synchronisation and time server solutions.

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Quick Diagnosis of a Dead Laptop LCD Display

Wednesday, April 1st, 2009

If you own a laptop computer, sooner or later you are going to be faced with a computer that has a display that has gone dark typically in one of two scenarios. In the most common case the LCD screen is damaged because of some physical event that caused the screen to be cracked or broken. Laptops do not take kindly to being dropped, especially when the case is opened and the accident occurs. In the second case there no physical damage and a malfunction in the video,power or control circuitry has caused the display to malfunction.

In the case of the cracked or physically damaged screen you need to determine if there is other damage to the laptop. The best way to do this is to plug in an external monitor using the video output connector at the rear of the laptop case. If the external monitor works and you see that your applications function then you know that you are looking at a LCD screen repair, and in the event you don’t repair the laptop you can still recover your data. Even if you elect not to repair the laptop this kind of failure is the best of a bad situation because the laptops still functions and you can still recover your data.

If the Laptop screen hasn’t been physically damaged, but the screen is still blank, you should still connect an external monitor as described above and determine if the rest of the laptop is functional. In the case where the screen is blank and an external monitor doesn’t work a more expensive diagnosis and repair scenario will probably be your only option.

It is always best to take these basic steps before you get a repair person involved. You should think through your repair options before you are confronted with a potentially costly repair decision.

The author is a computer industry professional in the service and repair industry. His career dates back to the early 1960’s and the early solid state large scale super computers. He has managed services organizations responsible for service of large PC networks and manged repair center operations. He has served on service industry councils of IBM, HP and Compaq. His website http://www.finestlaptops.com is focused on providing information on, and sources for cheap laptop computers.

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External Hard Drive With RAID – My Book Mirror Edition

Wednesday, March 25th, 2009

Western Digital My Book Mirror Editions are a great new form of data storage and backup. Western Digital is known for high quality external storage drives, but they have now added an extra layer of security with the ability to set RAID 1 or 0 on the Mirror Editions. Whether you need external storage for business or personal reasons, these drives are worth looking into.

The My Book Mirror Editions currently are available in two sizes – 1-terabyte and 2-terabyte. As with other My Book drives, these do not come at a small MSRP. MSRP on these units are $289 – $549 dependent on the size you get. Keep in mind, these are suggested retail prices; the units can be found for much less.

The My Book Mirror Edition measures 6.54-inches x 6.06-inches x 3.87-inches and weighs around 5 pounds. This, in concatenation with its polished black exterior and book shape, makes the unit presentable in any atmosphere. Additionally, there is a blue LED light, on the front face of the box, which lets users know the status of the My Book, with a simple glance.

Users have the choice between either RAID 1 or RAID 0 on the My Book Mirror Edition. Using RAID 1 reduces the overall storage size to half, but provides you with a duplicate copy of your data on the second drive. RAID 0 provides you with a bit less security – no replica of data – but gives you more overall storage space. The drives are somewhat customizable to your needs.

The unit has a Drive Manager, which enables users to view the status, temperature, and capacity of the unit. Users can also change the configuration through Device Manager. You can change from RAID 1 to RAID 0 and vice versa. (For consumers who do not understand what this will do, your data will be wiped if you reconfigure your unit to a different RAID setting.)

Western Digital implemented an application called WD MioNet, which allows users to access their drives via the internet. You can now access your data regardless of where you are at. Additional applications and software are available, some of which are WD Anywhere Backup, a 30-day trial of Memeo Autosync, Google, Desktop Search, and Picasa.

Installing additional software and transferring files is very user-friendly. The overall user-interface, and ease of navigation and use, enables users of any skill level to operate the My Book Mirror Edition nearly effortlessly.

If one of the hard drives, in the unit, happens to fail, users can easily replace. Each hard drive is simple to remove for this purpose. The unit only uses USB connectivity; no there is no way to connect via FireWire or eSATA.

If you are looking for an external drive for data backups, and would like a little bit of security with it, the Western Digital My Book Mirror Edition is the right move. With a little bit of bargain hunting you can add this unit to any network with a small dent in your pocket book.

Author Matt Ryan can help you save money on Western Digital Hard Drives. Visit MiracleShopper to find information and pricing on External Hard Drives and more.

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Choosing a Computer Network Training Provider

Wednesday, November 26th, 2008

When you are in a place where you are looking at the options that you need to get your workplace online, you will find that you are looking at something that can be greatly informed by your choice of network training provider. The truth of the matter is that no matter what industry you work in and what you are doing to make sure that you can get the results that you need, you are going to find that you are in a place where you need to make sure that you and your staff have a thorough understanding of the technologies and the networking that you are using. You can have the best system around and it will do you very little good unless you know how to use it! When you are looking to make sure that you are getting the most out of your network training, make sure that you consider a few points about your network training provider.

The first and most basic thing that your training provider should be able to accomplish is that they need to make sure that they can convey simply and clearly how the technology works to your staff. In the first place, think about how adept your staff is. Have they recently just come from one good networking system and now they are going to another, or are they in a place where this is all brand new to them? In either case, the training needs to be tailored to their needs and their comfort, so make sure that you can find a trainer who will do that.
Another point that you need to make sure of when you are looking towards hiring a good computer network training provider is that you need to think about how intimately they are familiar with the system that you are getting installed.

- What kind of experience do they have, and what can you do to make sure that you are in a good place where they get the information that they need to get across?
- In what ways are they preferable to an in house system and what do they offer when you are looking to get a certain amount of people competent on the material at hand?

You will find that the more information that you can get when you are classifying their work, the better off you are.

When you want to make sure that you are getting the best trained network engineers out there, you will find that you are in a place where training is crucial. Make sure that you invest in a training provider who will give your engineers the training that they need to thrive. Take some time and make sure that the people that you are looking to work with will give you the best results when it comes to getting your engineers the real life, hands on experience that they need.

Take some time to consider what you need out of your computer network training provider and make sure that you get it. Finding a trainer who suits you and who can help you achieve your goals will pay off in the long run.

Derek Rogers is a freelance writer who writes for a number of UK businesses. For information on Network Training, he recommends Prodec Networks, a leading provider of computer network training.

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USB Flash Drive Operating Systems

Saturday, November 22nd, 2008

Did you know that you could get an entire operating system on a flash USB drive? Most firmware in modern PCs allows booting from these drives. That means that a bootable flash drive could allow you to launch an operating system, this is commonly called Live USB and applies mostly to Linux operating systems. However, there is a MS Windows version available and some versions of BSD are also available on flash USBs.

Live USBs are good special purpose or brief tasks like doing an operating system install or disk cloning operation across a network, loading a minimal kernel for embedded operations and maintenance tasks.

A properly configured Windows USB flash drive will allow you to install a version of Windows XP on a drive, with extra software if there’s space. To do this, a special utility is required, as well as a fairly large drive. You will end up with a portable, compact emergency version of your operating system.

Live USBs are more commonly used by Linux operating systems, and are closely related to the now-common live CDs. Like CDs, USBs can be used to help test a distribution, recover data and many other tasks. Live USBs have many of the same limitations and benefits of a live CD. It is, however, easier for a live USB’s data to be changed, since CDs are usually permanently written. That makes it easier to use a live USB as personal storage, allowing a user to carry their preferred applications, operating system and configuration. Sharing a single system between multiple users is much easier in this case.

Live USBs can also provide extra privacy, since the USB device is carried by the user and storage in a safe location is easy. However, the small size of these devices also means that they are easily lost and stolen; making backups and encryption more important for USB flash drive operating systems than normal desktop operating systems.

Since USB drives have no moving parts, they are able to have a faster seek time than optical media and hard drives, this means small programs start faster from USB flash drives than from a live CD or hard disk. However, the low data transfer speeds of some USB devices can make booting from them very slow. In addition, older computers may not have a BIOS that supports booting from USB devices. Booting an operating system from a USB drive may slightly reduce the life of the flash drive.

Carrying your own personal operating system in your pocket can be extremely useful for travellers or people using shared computers. Some sites offer tutorials on simplified flash drive installation for many different distributions of Linux (which is the most popular OS for this purpose). These tutorials mean it is much easier to install, boot and run your preferred distribution, with all your settings and files, from a very small drive. Just be sure you have a large enough drive and that you are using it in a computer capable of booting from the USB port.

Note: USB 2.0 capability greatly speeds things up, as well.

Derek Rogers is a freelance writer who writes for a number of UK businesses. For logo branded promotional flash drives, he recommends Flashbay.com.

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What is a WAN Service and How Can it Help?

Saturday, November 1st, 2008

A WAN, or Wide Area Network is a computer network that covers a large area, such as those whose communications need cross metropolitan, regional or national boundaries. A WAN is used to connect local area networks, or LANs and other networks together; the linking of these computers allows users and computers in one area to communicate with users and computers in another location.

Most WANs are designed for a single organisation and are privately used. Those that are built by ISP, Internet Service Providers, provide connections from various organisation LANs, or local area networks, to connect to the Internet, in this way, communications can be delivered over national boundaries.

These types of communications include;

  • Instant messages
  • Emails
  • Real time auctions
  • Online ordering placing

This in turn can reduce costs for companies by eliminating the need for travel and expensive long distance phone calls.

The benefits of using a WAN are that you can connect computers that are located over a vast area together. A network that can exchange data between sights is efficient and effective. The WAN enables computers to communicate with each other, some at different times and others at the same time. Not only can data be shared, but video as well, WANs are used for video conferencing and web casting. When communication is being shared between computers, each operator can access the same information at the same time.

When using a WAN, major corporations can reduce the branch office in house costs by enabling a centralised data centre to handle backup and storage resources. The use of a WAN also improves employee productivity by increasing and accelerating work applications as well as reducing replication across the WAN.

The use of private WANs have significant benefits also; the network is safe, secure and as it states, private. This type of network can reduce support and maintenance costs. There is an increased speed of the data that can be transmitted between sites because no other users are on the network. There is the ability to quickly access data that might be stored at different locations. This is also a great way for a company to provide training to their employees without the expense of airline tickets, hotels and providing meals for them.

As you can see, the benefits of having a WAN are vast. Whether you are using a private network to utilise quickness and efficiency between your satellite offices, or whether you are using a public WAN such as the Internet to purchase an item, communication between geographic areas is an important role in our society. Many people have used the Internet to gain knowledge by attending on-line college classes, or just have some fun playing an on-line interactive game; all of these activities were accessed using a WAN. The use of WANs offers opportunities never before possible for businesses as well as the everyday consumer.

Derek Rogers is a freelance writer who writes for a number of UK businesses. For Business Internet Services and WAN Services, he recommends Iconnyx.

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