WiFi Demystified – Part II

In the first part of Wifi Demystified we explained the basic and advanced Wifi configuration and settings. In this section, we will get acquainted with the various security configurations in a typical WLAN network.

Security mode disabled

Now it is perfectly alright to disable your Security mode (set the option on the gateway to “None”), but that will allow any Wifi client to connect to your AP and utilize it’s bandwidth thus hampering the performance of the intended audience. However, it is observed that most APs in India have no security mode set against them are vulnerable to attacks.

WEP security

Wired Equivalent Privacy, is the basic security mode in all the APs. It consists of 64-bit or 128-bit encrypted passkey. The next part is a little confusing : A 64-bit WEP key in Hexadecimal format is 10 characters long while in the normal ascii (or alpha-numeric) format is 5 characters long. The more secrure 128-bit key in 26 characters in Hexadecimal format and 13 characters in ascii format. Now, some routers may not even have an option for both 64-bit as well as 128-bit keys, or they might display something like WEP-40 or WEP-104 (since 64-bit key is actually derived from a 40 bit key and a 128-bit key is derived from a 104-bit key). I have also seen some routers which will not thrown an error if you do not put more than 5 or 13 characters for the respective mode, since they probably account for the user’s ignorance and truncate it internally.

Another notion, present in only a few APs is the key-index. You can set upto 4 WEP keys and then decide a “key-index” or “default key” from these 4, which will be the actual key used.
Although WEP key is better than having security disabled, it is a fairly easy security to crack. Even a moderate cracker will be able to crack the WEP key in a few minutes as softwares are available for doing these. (Maybe I’ll write a separate post on just WEP key cracking next).


This section is further sub-divided for better understanding.

Wifi Protected Access is essentially a Certification program by the Wifi Alliance which was created in response to the concerns about the weakness of WEP as a security mode. However WPA was a certification based on IEEE’s 802.11i draft which was still scrutinized by the community. When the draft was finally ready, implementing the full standards, a huge number of Wifi products based on WPA had already flooded the market and hence it came to be known as WPA2 and the new products had to be backward compatible with WPA.

TKIP /AES-CCMP : WPA uses the Temporal Key Integrity Protocol or TKIP as an encryption method which makes it a lot harder to crack then WEP. The WPA2 security however used the more advanced AES (Advanced Encryption Standard) algorithm which is used by the CCMP (Counter Mode with Cipher Block Chaining Message Authentication Code Protocol) encryption protocol. This protocol makes it impossible for crackers to crack the passphrase, unless of course, the cracker has a super computer at his disposal, in which case it’s just a matter of a few months or years :-).

Both these encryption types accept a pass-phrase (a password), of 8 to 63 characters long, the longer and more random, the better.

Personal/Enterprise mode

Both WPA and WPA2 can be configured in the Personal as well as Enterprise modes.

Personal : Personal mode is also referred to as WPA(WPA2)-PSK or PreShared Key. In this mode you simply setup a passphrase (between 8-63 characters) and share it with users who you wish to connect to your AP. This is usually the default mode to be set in home or SOHO APs since it does not require any additional infrastructure.

Enterprise : In Enterprise mode, the authentication between the Clients and APs happen over the 802.1X authentication protocol. In order to achieve this, there needs to be an external RADIUS server with user credentials in the network (or atleast reachable by the AP). Setting up a RADIUS Server and 802.1X infrastructure is complex and out of the scope of this post, but briefly this is how it works :
The client tries to associate to the AP. The AP sends the Client’s information to the RADIUS Server (this usually happens over a wired connection). The RADIUS server does the authentication and authorization of the user. If the AP gets a “Go Ahead” from the RADIUS, it allows the Client to associate.
As you can see, this is a complex procedure and usually not used in Homes or SoHo environments, which is why most APs may not even have an option to set it.

This completes the WPA/WPA2 configuration settings. Now, just to make sure we are on the same page, WPA2 uses AES-CCMP while WPA uses TKIP for encyption (WPA2 could use TKIP, but that would beat the purpose of the standard). Both WPA and WPA2 can be configured in the Personal as well as Enterprise modes, but Enterpise mode is too complex for home users and should opt for the simpler yet as powerful Personal mode.

So, if your Wifi network has some old clients (more than 3-5 years), it is best to have the security mode set to WPA-Personal and encryption to TKIP. However, if all are relatively new machines, a WPA2-Personal and AES-CCMP pair would make your Wifi almost impenetrable.


Wireless Protected Setup, is a new Security Configuration methodology. Using WPS, clients can connect to the AP by the simply the push of a button or entering a simple 10 digit Pin code. Needless to say, WPS must be supported both by the AP as well as the Client. WPS is just a convinient way to associate clients and APs and it “sits” on top of the traditional security methods, WPA and WPA2. Thus, before initiating WPS, the WPA parameters should be configured on the AP.

WPS works in two scenarios, Push button method and Pin method.

Pin Configuration method : Some APs will have a WPS pin printed on a label on the device. In other cases, the Client-side generates a unique pin everytime WPS is initiated and this pin has to be entered on the AP (Yes, you read correct. It’s NOT the other way round).

Push Button method : To support this method, both the AP and client either need to have an extra push-button on the device or a soft-pushutton clickable on the Wifi config UI, to initiate WPS.
In both the above cases the basic working is the same : Once WPS is initiated by either of the methods, the Client has 2 minutes to do the same before the session expires. For example, once the button is pressed on the AP, the user should press the WPS button(either hard or soft) on the Client within 2 minutes to get connected. No client can connect after two minutes. If requried, the process needs to be re-initiated. Similarly, once a CLIENT generates a WPS pin, it should be entered and saved on the AP within these 2 minutes for a successful association. This two minute gap is called the Walk period.
Now the attentive user will see the obvious flaw in this system : If a button has been pressed on the AP, any client with WPS capability in the vicinity can associate itself. Well, that’s true, but the other client has to do that within the Walk time. Also, WPS is meant more for convinience than for tighter security, so yeah, there is a trade-off involved here.


MAC Access Control List lets an AP control which and how many clients will connect to it. However, not all APs have an option to limit the number of clients. Wifi MAC ACLs have a notion on “blacklists” and “whitelists”. When a “blacklist” ACL is applied, all the clients whose MAC addresses   are in that list will be prevented from associating with the AP. Conversely, when the ACL is of type “whitelist”, only the Clients whose MAC addresses are in the list will be allowed to associate, rest all will be rejected. This allows a more broader control on who can or cannot connect to the WLAN.

With this, we have covered the Wifi basics from a layman’s point of view. However, this information should be enough for anyone to configure a Wireless home router in a satisfactory working mode.

Creating Custom Brushes in Photoshop – Part 1

In my previous tutorial, I taught you how to load/install new brushes in Photoshop. In this tutorial you’ll learn how custom brushes are created and saved. Once again it is a very simple tutorial but if your creative enough you can create wonders.

You’ll learn to create a elliptical brush and this brush will be used in my next tutorial where you will learn to create bokeh effect in Photoshop. Its all about creation ;)

Step 1:

Open a new transparent document. Once done, select the Ellipse Tool (press U) and draw a circle.


Step 2:

Once done, in Blending Options, change Fill Opacity to 75%. Don’t get confused. Change the Fill Opacity not the Opacity. Follow the screen shot…



Enable Stroke and change the size to 10px, position – inside and color to black. Your almost done with your new brush.

Step 3:

Open Edit and select Define Brush Preset and name your newly created brush. Your new brush has now been saved. Note down the brush number displayed on the left side.


If the Define Brush Presetoption is disabled then do the following. Duplicate the layer by pressing Ctrl+J on your keyboard. Disable the old layer (make it invisible) by clicking on the small eye eye With the new layer selected, now try defining the new brush preset by clicking Edit.

Step 4:

To save a copy of your brush separately, click Edit > Preset Manager and select your brush from the list (remember the brush number?) and click Save set.

If you’ve forgotten your brush number, then keep your cursor on the particular brush to display its name and save it. Your done! :-)

Now you have learnt to create and save your own custom brush. In my next upcoming tutorial, you’ll learn how to implement this particular brush to make something creative. Stick around :-)

How to Create Psychedelic Wallpapers?

Take a look at my wallpaper today. If you stare at it for a bit, does it appear to move around on it’s own? Isn’t that creepy … or maybe it’s just me?


If you’re interested, I’ll show you how to create an infinity of wallpapers like this one using only the MS Paint application which is included with every copy of Windows.

* Open Paint
You can usually find it in your Start Menu under “Programs” then “Accessories”. If not, go to Start > Run, then type “mspaint”.

* Set the size
In Paint’s menus, go to Image Attributes.


Then set it to 8 by 8 making sure you’ve selected the Pixels radio button as well.


* Zoom in
The normal zoom setting is too small to work with. You can adjust the zoom settings by choosing “Image”, “Zoom” then “Custom” in the Paint menus.


Once the Custom Zoom dialog appears, set it to 800%


Now you can see blank square which is 8 x 8 pixels.


* Show the Grid
I recommend that you turn on the grid setting so you can see each pixel easily. Select “View, “Zoom” and “Show Grid” to see the grid display.


Now you can see each pixel.


* Fill the background
Pick a color on the color box.


Then choose the fill icon.


Click anywhere on the grid and the color you’ve chosen will fill the entire square. I’ve chosen black in this case.


* Create a pattern
Pick the pencil icon …


… then choose a few different colors and fill in your own crazy pattern. Here’s one I’ve finished.


* Save as bitmap
Once you’ve finished, save the pattern as a bitmap (*.bmp) by making sure you’ve got this selected in the “Save as type” pull-down box. I’ve found that the next step is easier if you save the .bmp file in your “My Pictures” folder.


* Set as Wallpaper
Right click on an empty area on your Windows Desktop, choose properties, then choose the “Desktop” tab. Now select the bmp file you’ve created. If it’s in your “My Pictures” folder, it should already be listed. Before you hit “Apply” or “OK”, be sure to also pick “Stretch” in the “Position” pull-down box.


It looks blocky before you hit the OK button, but Windows will smooth out those rough edges when it stretches the little bitmap to cover your desktop. If you’ve chosen to “hide” your desktop icons, this bitmap will still appear blocky and you’ll have to “Show Desktop Icons” to get the smeared effect in a stretched bitmap.

If everything goes well, you’ll have a great looking psychedelic wallpaper like the one I showed you at the top of this article. Once you get the hang of this, you can play with the size of the BMP and different colors to create your own weird universe of color.

Have fun!

10 Great Photoshop Tutorial Websites

Imagining present times without Adobe Photoshop can be quite difficult. Not only does this extremely versatile software let you fix that grainy picture you want to use as your new Facebook profile picture but you can also use it to create your own digital artwork.

However, using Photoshop, and by that I mean using it properly to its full potential, is hardly a cakewalk! To say that almost everyone who is new to Photoshop finds himself or herself a little confused is an understatement. So, to make your foray into digital art and photography a little easier, I will share 10 Great Photoshop Tutorial Websites with you.

Psdtuts+ is a great Photoshop tutorial website which updates its content regularly. Also, this a great website if you take a fancy to a wide variety of photo-manipulations. From tutorials on Applying Textures to uneven surfaces to Creating an original pin-up girl, Psdtuts+ not only has a vast range of Photoshop tutorials, but also explains these lessons in a friendly manner that is easily understood by all. Although complete access to all the material that can be downloaded, including all PSD files of tutorials is accessible only to paying members, the instructions can be seen by all visitors to the website.


Another great website for Photoshop tutorials is Tutorial9. All the Photoshop tutorials provided by this website are created by experienced teachers and are completely free. Tutorial9 also has an excellent stock of Photoshop tutorials. Some of the interesting lessons include those on how to Design an Epic Fantasy Scene with Photoshop, Create a Clean and Colorful Web Layout in Photoshop and How To Create An Abstract Floral Explosion in Photoshop among others.


PS Hero also offers great Photoshop tutorials for free. If you are starting out with Photoshop, this would be a great place to look for lessons as there are tutorials on many simple image manipulations that can be used to great effect, for instance, learning to create A Scrap of Notebook Paper or Grunge Photo Edges.


PSD Learning is a relatively new Photoshop tutorial website which has a wonderful stock of tutorials that will suit the requirements of not only those seeking to perfect their digital art but also novices who are only starting out with their game.


Another excellent Photoshop tutorial website that has started out recently is 10Steps.SG. With friendly navigation and fantastic content organized into categories, this is another great website to turn to for Photoshop tutorials.


If you want to learn how to create Incredibly Realistic Water Text in Cinema 4D and Photoshop and other interesting image manipulations, then you would love Abduzeedo. Not only do you have extremely helpful Photoshop tutorials for a host of advanced Photoshop functions but you are also provided with design inspirations that you can make use of while coming up with your own creations.


However, if you would rather master the simpler tricks first then Photoshop Contest has extremely helpful lessons.


You could even head to Photoshop Tutorials for more tutorials on the various Photoshop techniques.


If you are looking for Photoshop tutorials on creating WordPress layouts then you could visit PSD Vibe which has excellent tutorials for these among other lessons on interesting techniques.


Finally, in your quest for learning Photoshop skills, you could also try out the tutorials at Pxleyes.


How To Uninstall or Rollback Windows 7?

is a really good operating system, however users may still face one problem or the other, that is the major annoyance in software, what may work for someone, may not necessarily work for someone else.

So if you are a user who is having a problem with the OS, you might want to uninstall Windows 7 and then reinstall it again.

PC Tips box has written a article that will show you how to safely uninstall Windows 7.

The post gives to uninstall Windows 7 in the following scenarios.

  • You installed Windows 7 on a Windows-based computer
  • You installed Windows 7 on a computer that did not have an operating system installed
  • You upgraded from Windows Vista to Windows 7

Definitely a good guide to follow so that you do not lose your data or other important information will rolling back or uninstalling Windows 7.

How To Install New Brushes In Photoshop?

In this tutorial I’ll teach you how to install new brushes in Photoshop. This method is common and works with any version of Photoshop that you use. There are different methods of installing brushes but this is one common and easy-to-use method.

Step 1:

Open Photoshop and click on Brush Toolor press Bon your keyboard.


Step 2:

On the top click Brush Preset picker, next to brush size.


Step 3:

Now a window pops up on the screen. On the top-right corner you can see a small arrow pointing right. Click that. From the drop down select Load Brushes.


Step 4:

Locate your file (Note: Brush files have .ABR extension) and click Load


Step 5:

Once your done loading the brushes, scroll down and you’ll see your new brushes there.


How To Upgrade From Windows XP to Windows 7?

Tomorrow is the D-day when Microsoft will be releasing RTM to TechNet and MSDN subscribers among other people.


Windows XP users will not be able to directly upgrade to Windows 7 and they will require to perform a fresh install which will mean that all the applications will be wiped out and you will need to reinstall everything from scratch on Windows 7.

Nirmal from Life Rocks has written a excellent upgrade path for Windows XP users to Windows 7 that will help you all your user settings and data to a  external drive and then restore them back on the new Windows 7 installation.

Also most of users will be easily be able to upgrade to Windows 7, so you can download the ISO and burn it to a DVD and then install it on Windows Vista without losing your settings.

To check if your PC is ready to be upgraded to Windows 7 or requires a fresh install you can download the Windows 7 Upgrade advisor.

Repair Windows Live Writer Continuous Crashes, Direct Download Standalone Windows Live Writer

Windows Live Writer is one of my favorite blogging tools, and I use it quite a lot to post to several blogs I write for, however out of the blue today WLW started to crash and did not even allow me to open it.

Every time I fired up Windows Live Writer it crashed after showing the splash screen as you can see below.


I tried to repair the software to no avail, restarted the PC and did almost everything I could, but the damn thing just would not work, but not for long, like we solve your trouble’s we find solution for ours too. BTW this post is written using WLW :-).

We were finally able to solve the problem and also directly download the standalone installer for Windows Live Writer and install it again, however we did much more than that, so here is a tutorial that will help you repair Windows Live Writer by performing , uninstall it, reinstall it and restoring Windows Live Writer settings, plugins and draft posts and get it working again.

Step 1: Use the Windows Live Writer Backup tool to backup your settings, drafts, plugins and save it to a safe location. It is very important you do this incase something goes wrong and you lose everything.


Step 2: Go to Add/Remove Programs or Programs & Features in and search for Windows Live Essentials and click on the Uninstall/Change button and uninstall Windows Live Writer. Read more on how to uninstall individual windows live programs.

Step 3: Go to your My Documents folder and rename the folder My Weblog Poststo something else, also go to the local settings folder and copy the Windows Live Writer folder and save it somewhere else, after you have created a backup, delete the folder from the Local folder.

In Windows Vista you will find this under C:\Users\username\AppData\Roaming in Windows XP you should find it under the Local settings folder for your user.

Please make sure you have backed up everything as suggested in step 1 before deleting anything.

Step 4: Once you have uninstalled WLW and followed step 3, directly download the Windows Live Writer application from here and install it.

Step 5: Once again use the Windows Live Writer Backup tool to restore the drafts, blog settings and plugins.

That’s it, hopefully this should fix a annoyance some of you have where Windows Live Writer does not start at all.

How To Uninstall Individual Windows Live Programs?

Windows Live Essentials is a useful suite of programs bundled into one by Microsoft, the suite includes several Windows Live Messenger, Windows Live Mail, Windows Photo Gallery, Windows Live Toolbar, Windows Live Writer and Movie Maker Beta and Windows Live Family Safety.

Once you install Windows Live Essentials you can make use of the individual programs without problems, but what if you want to remove one of the programs that you installed for example Windows Live Messenger?

If you are searching high and dry in the add/remove programs you may not find any entry for Windows Live Messenger or for that matter any other programs in the suite as they are all bundled under Windows Live Essentials.

Here is a step by step tutorial that will allow you to uninstall individual programs from Windows Live Essentials.


Step 1: Go to Add/remove programs or Programs & features in control panel and find the entry for Windows Live Essentials.


Step 2: In the window that opens up, select the Uninstall option and click on Continue button.


Step 3: When you click on the continue button, you will see a list of individual Windows Live programs that you can uninstall, just select the checkboxes next to the name of the program and click on Continue.

That’s it, the program you select will now be uninstalled from the Windows Live Essentials suite.

This can be used to uninstall Windows Live Messenger, Windows Live Mail, Windows Photo Gallery, Windows Live Toolbar, Windows Live Writer and Movie Maker Beta and Windows Live Family Safety.

How To Build Firefox Extensions?

are things that make a really good browser to use, and to be frank even though I like there are quite a few things that I need to depend on Firefox for.

Mozilla does allow users to develop Firefox extensions with Jetpack, however if you are looking for something more detailed, you can download a free e-book (limited time only) that will help you get kick started in developing add-ons/extensions for Firefox.


The book is written by James Edwards and usually retails for $9.95, however for a limited time you can download it for absolutely free. Thanks Sandip.

The book covers several topics including;

  • Learning about folder structures and files in a extensions
  • Developing user interface with XUL and styling with CSS
  • Advanced features with JavaScript
  • Keyboard shortcuts and I18N features
  • Guide to publish your add-ons to Mozilla add-ons gallery

Download Developing Firefox Add-ons e-Book [ with 46 pages]