Wednesday, February 14, 2007

Find your page rank !!

Hey, are you interested in knowing your page rank ??
If yes, visit the link..

Just enter your website name and click the button...thats it !!

Tuesday, February 13, 2007

An Internet Audio Streaming Server !!

Yeah I mean it...With an audio streaming server you can setup your own Internet Radio station !! Well, in this post I would like to introduce audio streaming server - Icecast server.

Icecast Project

Icecast, is a collection of programs and libraries which help to stream audio over Internet.
Icecast has three basic components they are
    • Server
    • Source
    • DSP
Server (Icecast)

The server in the case of this tutorial is where the listener connects to to listen. The job of the server is to broadcast the audio data recieved from the source to the listeners. What icecast does is it streams audio to listeners.

Source (IceS)

The source is where the audio data for the server is provided from. IceS is a program that sends audio data to an icecast server to broadcast to clients. IceS can either read audio data from disk, such as from Ogg Vorbis files, or sample live audio from a sound card and encode it on the fly.


DSP stands for "Digital Signal Processing". In terms of streaming, it just sends the data to the server in digital form, and if necessary, re-encodes the data to a more suitable form (MP3, OGG, specific bitrates). It handles socket connections, timing of data etc. Libshout library is the library used for performing these functions.

Sunday, February 11, 2007

Fun in google !!!

Have fun in google !!!

Make your own Google search.

here replace 'Bonnie' with your name !!

The best p2p I have ever used !!!

I am talking about Ares...

Here is the short description of Ares. Well, Ares is a p2p software. Which can be used to download anything under the sky !! Yes, I mean it.

I recommend Ares because its a small file usually comes around 1.4 mb. And its a free software. I use this software to download mp3s, hollywood films, music videos and so on.

There are so many features in Ares. Advanced search for all types of media files. And another good feature is the ability to preview audio, video files while their download is in progress. Ares runs on its own Decentralized Network. Another feature is that it has a chat window, with that we can chat with other Ares users, browse user's shared folder etc etc..

Well try it out !!

You can download the software from

Some BitTorrent links !!

Links to BitTorrents could be found at the following websites....

Torrent !!

{ Read the previous posts, its the continuation...}


As said in the previous post, Torrent is a metadata. The word metadata means data about another data. An example is dictionary.

So in BitTorrent a torrent is the one that has the extension .torrent. This file contains the data about the data which you want to download. Normally when you click a link to download a file, actually this torrent file is send to your computer. And this torrent file contains the location of the data which you want to download plus some extra data. Normally a torrent file contains informations about the tracker, the data and the computer which cordinates the file distribution.

So inorder to share some data, the client first prepares the torrent file. And the other peers download these torrent file and connect to the specified tracker, which tells them from which other peers to download the pieces of the files.

Important BitTorrent terms !!!

{ Read my previous post to know about BitTorrent...}

1) Peer

A peer is another computer on the internet that you connect to and transfer data. A peer does not have the complete file. It has bits ans pieces of data.

2) Torrent

Torrent refers to the small metadata file you receive from the web server. A metadata is data about another data. More on Torrents in my next post.

3) Seed

Seed is a computer that has a complete copy of a certain file. This file is divided and shared among many clients.

4) Swarm

The group of machines that are collectively connected for a particular file.


A server on the Internet that acts to coordinate the action of BitTorrent clients.

Bit Torrent ???

We have been hearing this word for quite a long time!! right ?? What exactly is Bit Torrent ??
Well, in simple words Bit Torrent is p2p (peer to peer) file sharing protocol. It is designed by Bram Cohen. It is designed to provide file transfer among multiple peers across network. It is now maintained by BitTorrent, Inc.

Now little about the working of BitTorrent... There is a central server (called a tracker) which coordinates the action of all such peers. The tracker is meant for managing connections, it does not know the content of the files being distributed, and therefore a large number of users can be supported with relatively limited tracker bandwidth.

Lets consider an example. Suppose there are 4 persons A, B, C and S. 'A' has some data which B and C doesnt have. 'B' has some data which C and A doesnt have and similarly 'C' has some data which A and B doesnt have. These A, B and C are trying to get full set of data. So first A announces it has the data that the other two doesnt have similarly B and C also announces about their data. So what they do is, they share their data until eachone has got full set of data. And the 4th person 'S' is called seed. S has the full set of data. The function of the seed is to distribute the data and share it among A, B and C and these A, B and C will share that data among themselves until they obtain the full set of data. So the seed provides service without having the need of sharing the full set of data to the clients. This is the working of Bit Torrent. Now more about various terms of Bit Torrents in my next post !!

Friday, February 09, 2007

Lets see how google rank your page !!!

Well, in todays post lets see how Google ranks one webpage. The answer to this question is PageRank and Hypertext-matching analysis !!
I know you might be staring at this word. Yes Google uses a very efficient algorithm to rank our page . Even though Google didn't reveal their page ranking algorithm (Ofcourse they won't !!) we will get a small idea about their algorithm from their company pages.

In Google's PageRank they checks the entire link structure of the web and determine which all pages are important. Next they perform a hypertext-matching analysis to find which pages are relevant to the specific search being conducted !!

Inorder to get good PageRank, you need to get good links from related sites which points to your site. The more links point to your web site, the better your rankings. One thing about the quality of links its better to have a link that contains the keyword other than having 'click here' on the links.

Now hypertext matching analysis. Google, instead of simply scanning for meta-tags they analyze the full content of a page and factors in fonts, subdivisions and the precise location of each word.

Now, I hope you people got some idea about PageRank !!

Thursday, February 08, 2007

Monolithic and Microkernel architectures !!!

As I said in my previous post, I am going to explain about microkernel and monolithic kernel architectures. Read my previous post to learn about kernel.

Microkernel Architecture

In the microkernel architecture the kernel provides only a necesary minimum of functionality and can be implemented in a small and compact form. Building on this microkernel, the remaining functions of the operating systems are relocated to autonomous processes communicating with the microkernel through a well defined interface.


  • Less trouble to maintain
  • Individual components can work independently of each other and are easier to replace.
  • Developing process is less complicated

  • Microkernel architecture is slower than monolithic architecture.
  • Well defined interfaces are need to communicate.

Monolithic Kernel Architecture

In monolithic architecture the kernel is maintained as a single component with all the functionalities incorporated. This type of architecture is mainly used where good run time behaviour is the primary consideration.


  • Faster than microkernel architecture.
  • No well defined interfaces are needed for communication as in microkernel architecture.

  • Difficult to maintain.
  • Less stable.
  • Kernel often become very huge.
  • Bugs in one part of kernel produce many side effects.

An overview of UNIX kernels !!!

In this blog, I would like to share with you " An overview of UNIX kernels". Well some of you might be wondering what is a kernel ?? Am I right ?? Yes I am.

So here is the definition of kernel...

The kernel is the core of an operating system, it is loaded into main memory at boot time and it stays in the main memory until shut down. The kernel has two main responsibilities..

  • To service low level hardware programming requirements (e.g. responding to hardware interrupts).

  • To provide an environment for processes; instances of programs or threads in execution.

Mainly there are two types of kernels...monolithic kernels and microlithic kernels...More on that in my next post...

And now back to Unix Kernels....

Unix kernels provide an execution environment for the applications or processes. The applications can interact with other components of the system (mainly hardware) with the help of the resources, interfaces and the set of services provided by the kernel.

Processes and Threads

A process can be defined as program in execution. And thread can be defined as a sort of independent 'strand' in the course of a program execution. As opposed to processes, threads work on the same memory and can influence each other. The process of creating, terminating and synchronizing the process is controlled by a set of kernel routines.

Unix process/kernel model

In unix there are two modes of execution, they are user mode and kernel mode. User mode can be defined as a less privilaged mode. Because in user mode the process cannot access the kernel data structures. And the kernel mode is the high privilaged mode. In the kernel mode, a process can access all the kernel data structures. Normally, a program run in user mode but when a system call or interrupt comes it switch from user mode to kernel mode.

Re-entrant kernels

Unix has re entrent kernel. It simply means that several processes are executing in kernel mode at the same time. Yes ofcourse one process at one instant of time. Only one process will be executing and the other processes might be waiting. If the currently executing process needs
to do a read/ write operation on harddisk. The current process is temporarily stopped and the control is given to the device handler. And the kernel may start another process that is waiting. And when the the hard disk operation ceases the device handler raises an interrupt showing that the operation is over. And now the former process which was in the halt state comes back to execution. This feature in unix/linux kernels is called re-entrancy.

One way to provide re - entrancy is to write functions which allows to change the local variables but protects the global data structures from being modified. Such functions are called re-entrant functions. So in a re-entrant kernel an interrupt can stop a process even if it is in the kernel mode.

This is the basic overview of unix kernels.

Friday, November 03, 2006

What the heck is phishing ???

Phishing?? What the heck is that ?? In this section I am going to crack the term phishing!!!

Wikipedia says..phishing is a criminal activity using social engineering techniques. Phishers attempt to fraudulently acquire sensitive information, such as passwords and credit card details, by masquerading as a trustworthy person or business in an electronic communication. Phishing is typically carried out using email or an instant message, although phone contact has been used as well.

Phishing techniques

Phishing is some form of technical deception. It may be misspelled URLs or the use of subdomains are common tricks used by phishers, such as this example URL, Another common trick is to make the anchor text for a link appear to be a valid URL when the link actually goes to the phishers' site. Lets discuss various phishing techniques...

One method of spoofing links use web addresses containing the @ symbol, which are used to include a username and password in a web URL (contrary to the standard). For example, the link might deceive a casual observer into believing that the link will open a page on, whereas the link actually directs the browser to a page on, using a username of; were there no such user, the page would open normally. Such URLs were subsequently disabled in Internet Explorer, with the Mozilla and Opera web browsers opting instead to present a warning message and give users the option of continuing to the site or cancelling.

Some phishing scams use JavaScript commands in order to alter the address bar. This is done either by placing a picture of the legitimate entity's URL over the address bar, or by closing the original address bar and opening a new one containing the legitimate URL.

In another popular method of phishing, an attacker uses a bank or service's own scripts against the victim. These types of attacks (known as cross-site scripting) are particularly problematic, because they direct the user to sign in at their bank or service's own web page, where everything from the web address to the security certificates appears correct. In reality, the link to the website is crafted to carry out the attack, although it is very difficult to spot without specialist knowledge. Just such a flaw was used in 2006 against PayPal.

A further problem with URLs has been found in the handling of Internationalized domain names (IDN) in web browsers, that might allow visually identical web addresses to lead to different, possibly malicious, websites. Despite the publicity surrounding the flaw, known as IDN spoofing or a homograph attack, no known phishing attacks have yet taken advantage of it.

Not all phishing attacks require a fake website. In an incident in 2006, messages that claimed to be from a bank told users to dial a phone number regarding a problem with their bank account. Once the phone number was dialed, prompts told users to enter their account numbers and PIN. The number was provided by a Voice over IP provider.

Now how to prevent phishing ??

One method to prevent phishing is to make the users aware of these phishing attempts. One newer phishing tactic, which uses phishing emails targeted at a specific company. This is called spear phishing.

Nearly all legitimate email messages from companies to their customers will contain an item of information that is not readily available to phishers. Some companies, like PayPal, always address their customers by their username in emails, so if an email addresses a user in a generic fashion ("Dear PayPal customer") it is likely to be an attempt at phishing. Emails from banks and credit card companies will often include partial account numbers. Therefore, one should always be suspicious if the message does not contain specific personal information. Phishing attempts in early 2006, however, used such highly personalized information, making it unsafe to rely on personal information alone as a sign that a message is legitimate. Further, another recent study concluded in part that the presence of this information does not significantly affect the success rate of phishing attacks, suggesting that most users do not pay attention to such details anyway.

Users who are contacted about an account needing to be "verified" can take steps to avoid phishing attempts, by contacting the company that is the subject of the email to check that the email is legitimate, or by typing in a trusted web address for the company's website into the address bar of their browser, to bypass the link in the suspected phishing message.

Anti-phishing software is available that may identify phishing contents on websites, act as a toolbar that displays the real domain name for the visited website, or spot phishing attempts in email. Microsoft's new IE7 browser, Mozilla's Firefox 2, and Opera from version 9.1 will include a form of anti-phishing technology, by which a site may be checked against a list of known phishing sites. If the site is a suspect the software may either warn a user or block the site outright. Firefox 2 uses Google anti-phishing software, which may also be installed under IE6. Spam filters also help protect users from phishers, because they reduce the number of phishing-related emails that users receive. An approach introduced in mid-2006 (similar in principle to using a hosts file to block web adverts) involves switching to using a special DNS service that filters out known phishing domains, which will work with any browser.

Sites have added verification tools that allow users to see a secret image that the user selected in advance; if the image does not appear, then the site is not legitimate. Bank of America uses this together with challenge questions, which ask the user for information that should be known only to the user and the bank. This feature (and other forms of two-way authentication and two-factor authentication) is still susceptible to attack, such as that suffered by Scandinavian bank Nordea in late 2005.

Sunday, January 23, 2005

Having Fun with your Registry

Having Fun with windows registry---By Bonnie
Make a backup of regedit before you edit your registry

To pop a banner which can contain any message you want to display just before a user is going to log on, go to the key:
Now create a new string Value in the right pane named LegalNoticeCaption and enter the value that you want to see in the Menu Bar. Now create yet another new string value and name it: LegalNoticeText. Modify it and insert the message you want to display each time Windows boots. This can be effectively used to display the company's private policy each time the user logs on to his NT box. It's .reg file would be:
REGEDIT4[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Winlogon]"LegalNoticeCaption"="Caption here."

Ban Shutdowns

This is a neat trick you can play on that lamer that has a huge ego, in this section I teach you, how to disable the Shut Down option in the Shut Down Dialog Box. This trick involves editing the registry, so please make backups. Launch regedit.exe and go to :
In the right pane look for the NoClose Key. If it is not already there then create it by right clicking in the right pane and selecting New > String Value.(Name it NoCloseKey ) Now once you see the NoCloseKey in the right pane, right click on it and select Modify. Then Type 1 in the Value Data Box.
Doing the above on a Win98 system disables the Shut Down option in the Shut Down Dialog Box. But on a Win95 machine if the value of NoCloseKey is set to 1 then click on the Start > Shut Down button displays the following error message:
This operation has been cancelled due to restrictions in effect on this computer. Please contact your system administrator.
You can enable the shut down option by changing the value of NoCloseKey to 0 or simply deleting the particular entry i.e. deleting NoCloseKey.
Instead of performing the above difficult to remember process, simply save the following with an extension of .reg and add it's contents to the registry by double clicking on it.

Disabling Display of Drives in My Computer

This is yet another trick you can play on your geek friend. To disable the display of local or networked drives when you click My Computer go to :
Now in the right pane create a new DWORD item and name it NoDrives. Now modify it's value and set it to 3FFFFFF (Hexadecimal) Now press F5 to refresh. When you click on My Computer, no drives will be shown. To enable display of drives in My Computer, simply delete this DWORD item. It's .reg file is as follows:

Take Over the Screen Saver

To activate and deactivate the screen saver whenever you want, goto the following registry key:HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\ScreenSaversNow add a new string value and name it Mouse Corners. Edit this new value to -Y-N. Press F5 to refresh the registry. Voila! Now you can activate your screensaver by simply placing the mouse cursor at the top right corner of the screen and if you take the mouse to the bottom left corner of the screen, the screensaver will deactivate.
Exiting Windows the Cool and Quick Way

Normally it takes a hell lot of time just Shutting down Windows, you have to move your mouse to the Start Button, click on it, move it again over Shut Down, click, then move it over the necessary option and click, then move the cursor over the OK button and once again (you guessed it) click.This whole process can be shortened by creating shortcuts on the Desktop which will shut down Windows at the click of a button. Start by creating a new shortcut( right click and select New> Shortcut). Then in the command line box, type (without the quotes.)
C:\WINDOWS\RUNDLL.EXE user.exe,exitwindows--for me
'C:\windows\rundll.exe user.exe,exitwindowsexec'
This Shortcut on clicking will restart Windows immediately without any Warning. To create a Shortcut to Restarting Windows, type the following in the Command Line box:
'c:\windows\rundll.exe user.exe,exitwindows'
This Shortcut on clicking will shut down Windows immediately without any Warning