Monday, 8 July 2013

Vulnerabilities in Facebook (Security question)

Hello everyone, today I want to discuss some vulnerabilities in facebook.
We all know that daily thousands of accounts are being hacked. People do this for many reasons. what ever the reason is, they needn't be a computer stud to do it. Let's see how people can simply get your account by following 5 steps, and also precautions to be taken to protect it.

Common ways to hack an account are phishing, by using a keylogger, by hacking primary email id and resetting password, social engineering or just guessing.

Now lets start with the social engineering. Many of us may think this is difficult, trust me, this works.

Let's start.


 To know the username or primary email address of account.

          For this go to the persons account and look the address bar or url bar.
For 80-85% accounts you can know user name by this way. 
But for some accounts you will end up with the following address bar from which you cant get the user name. 

You can guess the user name or you have other two options with you, Primary email address and recovery phone number. If you know the person then you can have any one of these two easily.

Step 2:

Now go to facebook and click on forgot your password.
You will then be redirected to identification check page.

enter the username or primary email id or the phone number. Press search.

Step 3:

Now you will be recovered to account recovery page.

Click on no longer access to this.

Step 4:

Now there are two methods
 1. Security question
 2. three friend method.

Now if the person kept a security question then it will direct you to a page and ask you for your new email id.

Click on any email-id (no need to be yours as this is just to know the security question).
This will direct you to their security question. This is the main step. To reach this point wont take more than few minutes.

Now if the security question is something like---

  • What is your home town 
  • In what city or town your mother born
  • Father's occupation...
These questions will make your day so simple as at some point of time you will know these from the person himself.
So if you can guess this then you can reset password.

Step 5:

Make an email account and you can reset.But wait vulnerable day. As in facebook they can get the account back within a day. So if you don't choose a right day then your work is vain.
      If this happens then facebook will block this feature for some days, but appears again in some days.

Precautions to be taken to secure account:

  • If you cant keep a unique security question then better don't keep it.
  • Its better to open account at least once a day.

Saturday, 29 June 2013

Duplicating Key with keyme

keyme introduced a process of storing your key in cloud and allow you to download it on demand. This will allow you to download it in 30 seconds.

Here creating an account is free and to download your key you need to pay around $20. For the basic
As this deals with keys the security is expected to be high. For this they store less information about key as possible. If you want to access keyme you must pass the verification. Fingerprint login and Email notifications make it more safer.

"We have all faced the immense inconvenience and unnecessary cost of getting locked out -- our KeyMe kiosks provide the ultimate solution to this problem," said Greg Marsh, CEO of KeyMe. "KeyMe acts as your digital key chain, making sure you can always get into your home or office."

Let's see how this can affect the security of People.

Tuesday, 25 June 2013

Indian Super Computers listing top 100 in world
Graphite for Teachers

Are you teacher? Wanted Innovative way to approach your students.
Then I think you should Visit Graphite

Common sense media Introduced this. In this you can search apps, games and websites to help you present your students. All the ratings are available with tools. When i said students, I mean elementary and middle school students. These tools may help them understand concepts with better observation.

These tools can be exactly searched by filters. Review for each tool is given by the teachers and are based on several learning dimensions to pick exact tool needed. This also include demonstration of best way to use the tool.

"There are no limits to what a great educator can achieve when they have the right tools. Graphite, a free service from Common Sense Media, helps teachers find, understand, and share the best digital learning products available." #copied from

Classroom teaching should be more digitized for better understanding, let's see how much this can contribute for that purpose.

Saturday, 22 June 2013

Project Loon

Heard of it? It is project taken by google to provide internet to every part of world. I don't actually know where this loon word came from. I guess Its from balloon(Bal'loon'). yes, they are trying to do it with the help of balloons.

Confused with this new "balloon powered internet?" You heard it right. Google is trying to send balloons to float in stratosphere which are carried by wind. When they want to change the direction of balloon, they change the altitude of balloon make it move in specific direction. People can connect to internet signal from balloon through antenna attached to house. Signal gets transferred from balloon to balloon, then to the global internet back on earth.

So they actually revolve around earth at a height of 20km and supply internet to the loon antennas. It can't be accessed by everyone without these loon antenna. But it is said that the internet looks pretty fast. 

According to Project Lead Mike Cassidy   "It’s very early days, but we’ve built a system that uses balloons, carried by the wind at altitudes twice as high as commercial planes, to beam Internet access to the ground at speeds similar to today’s 3G networks or faster." 

This project may or may not reach to every part of the world. But the basic Idea of providing speed internet for every part of the world looks pretty interesting to me. Lets see how much revolution it can bring to the way we use the internet. All the best to Google.

You may be interested in : Testing loon: Pilot Test
Facebook Spam: "She went inclusively nuts and lost all control of the razor-sharp axe"
How to enable Two-Factor authentication in Linkedin?:

Friday, 21 June 2013

Digital filter practical usage

Once filter design was mostly done by the analog filters. Even after the introduction of digital filters the design was not preferred due to the number of stages involved in the design. The need for memory to store the data(filter coefficients should be stored in digital filter design) made the design more costly.
So the design was only used where the cost was not a problem.

Later the digital filters made practical designs possible which are impractical and impossible by analog filters.
Example: Audio Frequency Range.

At this range the practical filter design was thought to be impossible, but with the advent of digital filter it is shown to be possible.

This gave reason for people to use digital filter. As the cost was still a concern the usage was still limited to only some design.

VLSI Development

As the VLSI developed, the cost of chips and power consumed, decreased drastically. This helped the development  of digital filter design and helped it to reach common people through the household instruments.
Advantages and Disadvantages of Digital Filter

Main advantages are as below
                 Reliability and Repeatability.
                 Component Drift.
                 Tuning Drift.
                 Precision Component.
           Programmability :
The main advantage of Digital filter lies with it's easy programmability  using software. Design process involves certain techniques through which filter coefficients are designed. With the designed Filter coefficients, the frequency response in magnitude and phase can be seen. Techniques to design these filter coefficients will be discussed further.
Corresponding Analog filter cannot be represented in software(see Practical usage).

        Reliability and Repeatability :
Digital filter is more reliable than analog filters by the same reason. In analog the component drift and tuning drift may be possible.Component precision can also influence the analog filter. These Problems are not there with the digital filter making it more reliable and repeatable than the analog filter.

Digital Filters make practical designs possible which are impractical and impossible
 by analog filters. 
Ex: Audio Frequency range
At this range the filter design was thought to be impossible as the tuning drift and also the component drift has a very sound effect. But with the digital filter, which don't have these problems, the design is shown to be possible. 

Main disadvantages of digital filter are

The number of stages involved in the digital filter design. 
High Power consumption in the filter because of the stages involved.
Cost involved with the hardware design.

Thursday, 20 June 2013

Overview of Digital Filter Design and Design Stages:

Digital Filter is designed in discrete time signal to reduce or enhance certain aspects of signal.
(i.e. for example to remove some harmonics in a signal.)
This can be done with Analog filter too. But the reason why people prefer digital filter is its reliability over Analog signal. Analog Signal need not behave same with the variations in temperature, frequency and other conditions. But the digital filter don't have Such problems as the digital filter coefficients will be programmed or the values will be stored in it, this makes the filter output depend only on the values stored or programmed. So the reliability and repeatability of Digital filter makes it more advantageous than the Analog filter design.

Basic Digital design stages or the components used in Digital Filter are

             -->Analog to Digital Converter (To convert analog input to digital).
             -->Microprocessor (To Store the data).
             -->Digital to analog Converter (To Get the final Continues Signal Output).

Main Disadvantage of this filter is the cost involved with design, due to the number of stages involved and also due to the need of memory elements to store data. These are the main reasons why the digital filters were not preferred once.

Next Comes:
The briefing on "Advantages and Disadvantages of Digital filter."

Enjoy. Thank you. :D

Thursday, 13 June 2013

Time Invariant Systems: (Better explained with practical examples. Read more... )

Monday, 10 June 2013

Worlds fastest super computer released by china Tianhe - 2
                           China's latest supercomputer Tianhe-2 measured a speed of 30.65 petaflops using  Kylin Linux operating system.(Read more...)
Apple announcing 50 billion downloads:     
Apple announcing a total of 50 billion total downloads from the Apple App Store. There are now 900,000 iOS applications available for download for iPhone, iPad and iPod touch, with 375,000 designed specifically for iPad. Apple also announced there were 575 million paid customer accounts, from those who could buy those apps.
Again the company made the point today that the app ecosystem is a financial boon to its developer community, too, saying that it has now paid out over $10 billion to third-party app developers. Apple paid developers $2.5 billion in 2011 and $1.5 billion in 2010, to give you an idea of the growth in years past.

Sunday, 12 May 2013

Causal and Non causal systems with real time examples :
Causal system and non-causal system, we all might have already known about it. But when it comes to it's practical examples in real time, there won't be many answers left with us.To understand it better, I found a blog useful. Its not about equations as we can get them anywhere, it's just about understanding.. hope it will be helpful.(for more Click here)

Monday, 18 March 2013

Virtual Box error:

This kernel requires an x86-64 CPU, but only detected an i686 CPU. Unable to boot – please use a kernel appropriate for your CPU.(Read more...)

Wednesday, 27 February 2013

Simple Proximity or Distance sensor:
A proximity sensor is easy to make. A basic circuit (Read more...)

Tuesday, 19 February 2013

Program to open your Web Cam using Open Cv Programming:

We previously wrote a program to load an image(Link) using open computer vision now let us see how to capture image from your webcam.



///////////////////////////////////  C LIBRARIES/////////////////
int main(int argc,char* argv){ 
CvCapture* capWebcam;                /// we will assign web cam to this later
 IplImage* webcam_img; char charchecksEnter;                // enter closes the program capWebcam = cvCaptureFromCAM(0); // for mutiple it will be 0 and 1 and so on......///
if(capWebcam == NULL ){  
printf("Error: capturing is NULL. \n"); 
 return(-1);                    /////**** Exit programme ***/////////
 webcam_img = cvQueryFrame(capWebcam);           /// assigning webcam_img to continues
                                                                                        ///  frames of images from web cam   ///
  if(webcam_img == NULL){ 
  printf("Error:frame is NULL\n");

charchecksEnter = cvWaitKey(10);   // waits for 10 ms. // 
if(charchecksEnter == 13)break;      // when enter key pressed. Program Breaks.. //

ENjoy.. :D

Wednesday, 9 January 2013

Cuckoo Search :

Cuckoo search (CS) is an optimization algorithm (finding a value x such that f(x) is as small (or as large) as possible) based on cuckoo species which laying their eggs in the nests of other host birds (of other species). The optimal solutions obtained by CS are far better than the best solutions obtained by an efficient particle swarm optimiser and in some ways better than the powerful genetic algorithem too.
May be this is one of the main reason for this to be famous.
CS is based on three idealized rules:
1) Each cuckoo lays one egg at a time, and dumps its egg in a randomly chosen nest;
2) The best nests with high quality of eggs will carry over to the next generation;
3) The number of available hosts nests is fixed, and the egg laid by a cuckoo is discovered by the host bird with a probability . Discovering operate on some set of worst nests, and discovered solutions dumped from farther calculations.
                 Yang and Deb discovered that the random-walk style search is better performed by Lévy flights rather than simple random walk.
The applications of Cuckoo Search into engineering optimization problems have shown its promising efficiency. For example, for both spring design and welded beam design problems, CS obtained better solutions than existing solutions in literature. A promising discrete cuckoo search algorithm is recently proposed to solve nurse scheduling problem.

You can read Xin-She Yang and Suash Deb's paper (Engineering Optimisation by Cuckoo Search) .
This can be implemented in Matlab. check this: 
ieeexplore papers can be referred for more reference.
Program To load a image From Your Computer using OpenCV:

////////////////////////////////////  C LIBRARIES /////////////////

int main(int argc,char* argv){          
 IplImage* img;                                                 
// declaring img in OpenCV
 img = cvLoadImage("E:\\Image.JPG",1);       /// loads the image from the location E: //
 if(img == NULL){                                         //// If Image is not present then the program terminates
  printf("Error: Frame is Null \n");
 cvNamedWindow("Original",CV_WINDOW_AUTOSIZE);  // loads window with auto size
 cvShowImage("original",img);                    //// shows the output image
 cvWaitKey(0);                                               // waits for the key stroke to destroy window.


Applications of Open Computer Vision:
              Application of this is growing day by day. The main advantage is the inbuilt libraries which makes many techniques easy.
             Simple techniques which are given as examples in OpenCV software are :
             In Video prossesing:
             1. Colour Tracking.
             2. Point Tracking.
             3. Motion Segmentation.
             4. Edge detection.
             Image Prossessing:
             1. Edge detection.
             2. Segmentation.
             3. Morphology.
             4. Histogrom.
             5. Distance Transform.
             6. Ellipse Fitting.
To do better you should be knowing atleast these techniques thorough.
             Major applications of OpenCV is based on identification,recognition and tracking. Now-a-days Major Robotic projects are done using this. For list of applications go to I will try to discuss the code for above techniques starting from basic code implientation.

Wednesday, 2 January 2013

Installation of OpenCV in windows:

Let us first install and see the applications later.
I am using windows platform so I am going to discuss here installation in windows using Microsoft visual studio.

Required to download:
1. OpenCV (click)
2. Microsoft visual studio.

I use Microsoft visual studio ultimate in my programs.
I will discuss step by step procedure to install. I will try to make it as simple as possible.

Step 1:  (Download required components.)                                                                           
  • Download OpenCV. It is an open source. You can download it by clicking on it. 
  • I prefer using Microsoft visual studio ultimate.                                                         

Step 2: (Extracting OpenCV to a location)
  • After downloading, go to the folder, right click on it and click on run as administrator.
  • Now select the location where you need to extract (Here I extracted to C:\ ) then click extract. 

It will take some minutes for extraction into the selected folder.
After extraction, name of the folder will be OpenCV. To avoid confusion while setting path change the name of folder to something else.(Let “OpenCV243”).

Now install Microsoft visual studio (Ignore if you have).
Step 3: (Set the path.)                                                                        
Follow the link of steps to set path.                                                 

Start à Control panel à System  à Advanced system settings

Advanced system settings à Environment Variables àPATH (Search for variable PATH in System variable inside Environmental Variables window)

Double click on the system variable PATH to edit it.

When edit system variable window pops up add C:\OpenCv243\build\x86\vc10\bin;

System variable value, i.e. the path added should be ended with semicolon (;).
To know why this is done, go to the location that is added to the variable. It contains all the .dll files which are to be added for the program to run.

Step 4: (Creating property sheet in Microsoft Visual Studio)                                                           
Here we create a property sheet which should be created in any program we write further in OpenCV. But a property sheet which was created can be added to any program. So creating    property sheet is crucial in the way we write the program.                                                             

Open Microsoft Visual Studio

Click on new project

Create a Win32 console application. Write a unique name for your New Project. Click OK.

Click Next..

Check for
Application type: Console application
Additional options: Empty project

Click Finish.
Now open the Property manager à Right click on Debug àAdd new property sheet.

Name the Property sheet and click Add.

There are three places where you should link locations or add. 

1.C/C++   à  Additional include directories à Edit à Add(C:\OpenCv243\build\include)

2. Linker à Additional Library Directories à Edit à Add (C:\OpenCv243\build\x86\vc10\lib)


 3. Linker à input à Additional Dependencies à Edit, Add


Note: This changes when your version changes. These are for OpenCV 2.4.3 as you can see 243d everywhere.

Now click OK. Your New Property Sheet is created now.

To write program go to    Solution Explorer à Right click on Source Files à Add new Item 

We write the program in C/C++ so select C++ file. Name it and click Add. Now you are ready to write Program in OpenCV.