Wednesday, 22 August 2007

What Is Wardriving And How Can You Prevent It

Imagine a car equipped with nothing more than a laptop computer, a portable GPS receiver, and a wireless network card slowly strolls through your neighborhood. Unknown to any onlookers, this is no ordinary vehicle; rather, it is a wardriving machine. As the car strolls past homes and businesses, a wireless network card (available at any electronics store for as low as $25) scans for any wireless access points. Anyone with a wireless network (and there are many out there) is vulnerable. The computer is looking for what is called an SSID. An SSID is your wireless network name and it is being constantly transmitted by your access point, letting computers know of its presence. The wardriver uses software such as Netstumbler (for windows) or Cismet (for linux) to scan the airwaves for SSIDs. The program can track various access points at once and monitor the signal strength. These programs can also check to see if the network is encrypted. The wardriver will generally configure his or her software to log any strong unencrypted signals. Using the GPS receiver, the coordinates of the strong signal will be recorded. After this preliminary drive, the wardriver can return to the locations that were recorded, and connect to the access point. Once connected to an unencrypted network, the wardriver can use the victim's internet access, and can also explore computers on the network. If files are being shared within someone's private network, all of that information is susceptible to a wardriver. Furthermore, once in the network, a wardriver can sniff network traffic and can view any information such as passwords and credit card numbers you send out to the internet - even SSL secured data. Wireless network vulnerability is a major problem, and as more and more households purchase wireless technology, the problem of insecure networks increases. Sound scary? Well this happens every day, and it doesn't take an expert to pull off. It doesn't take an expert to protect against either, however.

Steps you can take to protect against wardrivers:

There are a number of very simple steps you can take to protect your wireless network. For many of these, you will have to access your router configuration utility (check your manual on how to do this, you will generally need to type an IP address into your browser such as or

Don't broadcast your SSID. If you are broadcasting your SSID, this is the first thing a program will pickup and recognize. If you configure your router to not broadcast your SSID, it will be difficult to detect (but not impossible, for some software can sniff wireless communication, so if you are using your wireless network, the SSID can be revealed). If you are not broadcasting your SSID, but it can be guessed (such as if you are using a default SSID), cloaking is pointless. Due to this, remember to change your SSID from the factory default. This is not a 100 percent effective method to secure your network, but it is a good first line of defense.

Change the default password. When you buy a router, a factory password is stored. People experienced in working with routers know the default passwords for different routers (and the make of the router can be seen by wardriver software such as netstumbler). It is important that you secure your router with a good password.

Encrypt your wireless communication. I can't stress the importance of encrypting your wireless communication enough. Enable encryption and enter a key. Most routers are only capable of WEP encryption, but if they permit, use EAP encryption, it's more secure than WEP. Like cloaking your SSID, encryption is not 100 percent secure. Given enough time and determination, if someone wants to target you and access your network, WEP encryption can be bypassed using software such as AirSnort.

Filter the MAC addresses that are allowed to connect to your router. This would require that you enter your router configuration and input the MAC address of each wireless card you have. This will restrict access so that only your computers can connect to the router. You will need to obtain the MAC address (which is the individual identification address of a network card in the form a 12 digit hexadecimal number). If someone sniffs traffic and detects the MAC address of a computer wirelessly using your network, the wardriver could emulate that address and connect to the router, but this takes time.

If you configure file sharing on your computers, make sure it is password protected. You should not share files on your networked computers unless it requires an authenticated user to access. Set up the same user accounts on your machines so that your computers can share files.

With these relatively simple steps, wireless network users can secure their networks from wardrivers. Wireless networks are inherently insecure, and these tips will merely help you greater secure your network. If someone is really determined to gain access to your network, given enough time, a good hacker can get access. These tips will deter the average wardriver from gaining access to your network, however. Although these methods are not definite security measures, they will change your network from being something that can be hacked in a matter of seconds, to something that will take a determined hacker days if not weeks of work, all of which will have to be done while in close proximity to your network.

The author is a network security veteran, and CEO of Andertec Enterprises [], which specializes in onsite custom computer services for the Los Angeles area. Andertec also sells custom made-to-order computer systems, and has a line of revolutionary products at incredibly low prices including the best-selling CyberHome Complete home automation package.

CD and DVD Printing and Packaging - Preparing Your Artwork

Creating Artwork for CD or DVD On-Body Printing

Always use a template

This sounds fairly obvious, but there are a few very good reasons why you should always design using a template.

1. If you're printing onto a printable CDR or DVDR using an office inkjet printer then you need to carefully measure the printable area of your chosen disc because they can vary wildly in terms of exterior and interior diameter.

2. If you're going to be supplying your completed CD or DVD artwork to a professional printing company then they will have their own printable area constraints for the particular brand of CD or DVD that they supply. In some instances the printer may print right up to the centre hole of the disc but other printers may prefer not to. Check with them before beginning your design work and ask for a template to be supplied.

3. A template supplied by a professional CD and DVD printing company will be at the correct resolution (300dpi to 400dpi) and will specify any additional requirements such as inner and outer limits for any text that is included in the artwork. There is often a requirement for text to be at least 3 to 4 mm clear of the inner and outer edges of the disc. Also, the acceptable file formats of the finished artwork will be specified.

4. Always allow for artwork bleed. If you can supply an artwork file for CD or DVD printing that allows an extra 2 or 3mm outside of the external and internal printable disc surface diameters then this is ideal.

Most of the artwork supplied to us by experienced packaging designers is a 124mm square artwork that contains all the pertinent features well inside the printable area of the CD or DVD.

In our experience, most project delays with artwork, occur because the designer wasn't working to the correct printable disc area size or has supplied artwork at a resolution lower than 300dpi which would result in a poor quality print.

A Typical CD or DVD Template

Consider the Appropriate CD or DVD Printing Process

Screen Printing - If your design consists of solid block colours then the most effective print process for your CDs or DVDs would be screen printing. Screen printing involves producing fine mesh screens, one for each colour in the artwork, and then using a screen printing machine to apply UV light sensitive ink in the appropriate colour. This process can only apply up to 6 separate colours and should not be used where there is any colour gradient; the colour should always be solid and consistent.

If you're design features any specialist ink requirements such as metallic ink or fluorescent ink, then this will be the process used and the rest of your artwork will need to conform to the requirements for screen printing.

Lithographic (Offset) Printing - For complex images, such as photographic images or artwork featuring colour gradients, litho printing is used. This process involves using a rubber sheet wrapped around a cylinder to transfer the ink from a printing plate to the disc. Very high resolution prints can be achieved using litho printing but there are still a few constraints to be aware of, such as:

Don't use subtle colour gradients (transitions from one colour to another) over large areas. This can result in a "banded" print where there are not enough shades of colour to make a smooth transition from dark to light or colour to colour.

Don't use photographs taken in poor light conditions, they may look cool and artistic on a computer screen but when printed the subtleties of a dark figure against a slightly lighter background will most probably be lost unless you alter the exposure of the photograph which will open up another can of worms.

Avoid having large areas of one, solid colour in designs destined for lithographic print. It can be very difficult to litho print a large, flawless block colour area and you would more than likely get inconsistencies.
Creating Artwork for CD or DVD Packaging

The process used to print onto cardstock packaging is a digital printing process. The card will normally have a semi-glossy silk finish as standard. The packaging can then be finished with a gloss or matt laminate if required, depending upon your artwork requirement. Some of the considerations for CD packaging or DVD packaging artwork are the same as for CD or DVD on-body artwork, such as not using subtle gradients over large areas and not using dark photograph images, but there are also a whole host of other considerations due to the variety of CD and DVD packaging available and how it is printed and manufactured.

Card Wallets

A typical template for a basic card wallet will have the front panel on the left hand side and the rear panel on the right with the spine area marked. There are variations available such as extra folded printable panels or a "gatefold" design where there is a printable panel to either side of the centre panel which houses the disc.

When designing artwork for card wallets, you will need to give some thought to the following:

Crossover images - If the artwork for the front and back of the wallet is a completely different colour then you will have a hard colour transition at the spine fold. Movement may occur during the digital print process which could cause slight misalignment of the front and rear images, so wherever possible, try to use images that blend into one another or use a consistent colour for front and rear artwork.

Creasing - If your artwork is very dark and particularly for black artwork, you can sometimes experience a "cracking" effect along the spine or folded edges of the card where the dark ink at the fold cracks away from the card and you see white card exposed beneath it along the crease. You need to run a test print and try carefully creasing the spine if you're doing your own printing, to check whether your material will suffer from this effect. If you're using a professional printing company ask to see samples of dark coloured, folded card packaging to check the creasing process used by your printer won't cause this effect.

Text Position - Keep any text in your design at least 4 to 5 mm away from any edge in case of slight printing misalignment.
CD Jewel Case Booklets or DVD Case Booklets

Very often, CD or DVD packaging will require a booklet of some sort to accompany the disc. In the case of audio CDs they usually contain lyrics and acknowledgements of anyone who worked on the project. In the case of computer software supplied on CD or DVD, the booklet would contain instructions on how to use the software.

The printing material is obviously a lighter grade than that used to make card wallets but the same considerations need to be acknowledged.

A dark print needs to be creased correctly to prevent "cracking" as in the case of the card wallet folds.

Crossover images need to blend into one another, again, as with the card wallet

Text needs to be kept 4 to 5 mm away from any edge as well as the crossover edge down the booklet spine

When a booklet contains many pages, an effect known as "creep" occurs because of the bulk of the folded paper which causes the inner pages to extend further out than the outer pages when they are folded. The creep will vary as the number of pages and the paper thickness increases. The greater the number of pages in a booklet, the greater the need to ensure all text, graphics, images and objects are kept a minimum of 10 mm inside of the vertical trimmed edge.

If your booklet contains more than 2 printed panels bear in mind that booklets can only be made with page numbers that are a multiple of 4 (4,8,12,16 etc.) as each new sheet will have 4 printable panels.

When laying out the design for your booklet, consider carefully where each page should be positioned on the template. For example, in an 8 page booklet pages 1 and 8 will be printed on the same sheet with page 1 on the right and page 8 on the left. The rear side of this sheet will feature pages 2 and 7, with page 2 on the left and page 7 on the right.
Create a rough mock-up of your booklet before beginning the design work in order to understand clearly how pages are positioned in relation to one another when printed.

Digipack Printing

A digipack is a cardstock CD or DVD packaging solution with a plastic CD holding tray glued onto the inside right-hand panel, where the design is printed onto one side of the template.The template is then folded and glued to form a robust and stylish package. As with the Card Wallet above, you will need to consider the position of crossover images but also this is one packaging option where you will definitely need a template to understand how the panels that make up the finished product are positioned so that all images are correctly orientated.

In Summary

Hopefully, the information contained in this article will assist you in creating your CD or DVD disc and packaging artwork and help to eliminate some of the commonly made and potentially costly errors that are possible when embarking upon your first project of this kind.

Even for experienced disc art and packaging art designers there remains a need to check and double check that the artwork meets the printer's requirements as different printers will often have different working parameters.

Good Luck!