The trainer introduced a simple tool that can be used to classify a person to the preferred learning style that suited best based on a series of questions and preferences. What I found most interesting was how accurate it was when I did it for my self.

I was in the blue category. This meant that my strengths were in concepts, theory and reflection. I would prefer to:-

• learn by thinking through experience, judging the accuracy of the encounter and examining details and specifics
• take time to reflect and ponder on the experiences
• excel in traditional lecture-style environments
• in conflict situations dissect the problem – determine facts, presenting them systematically in a conclusion.

I would NOT prefer:-

• information that is out of sequence
• pass/fail grading rather than scores
• group grades
• teachers who do not prevent cheating

The full list and the assessment tool can be downloaded from the following links (full credit goes to Centre for Learning and Development, ECU). What is your learning style? While it may not be completely accurate for everyone, it definitely gives a few thoughts to ponder.

Learner Style (PDF)

Learning Style Tool (PDF)

Every day since I was born,
My mother cared for me.
Now that’s a lot of caring,
As anyone can see.

Please, Lord, protect my mother,
And keep her safe from harm,
For she is a cherished person,
With great wisdom, love and charm.

Lord, it’s my mother’s birthday
So please, help her to see
How much she means to us,
Her loving family.

By Karl Fuchs

May Allah, the Lord of worlds bestow His forgiveness and blessing on you, and fill your life with happiness.

Happy Birthday Mom

Image Source: Courtesy of Nimmy’s Experiment with Blogging

There have been similar attempts made in the past (e.g. work done by Neils Provos and Peter Honeyman).

This project is just a precursor to the lager work that I’m doing for my research, and also as an excuse to learn more about parallel computing. More details about the project will be posted as it develops…

The following two part video lectures are really good and to the point and covers all the ground work needed to get a good picture of what MPI programming is.

Have a go, its kind of addictive

A German poet called Johann Wolfgang Von Goethe once said, “Whoever wishes to keep a secret must hide the fact that he possesses one”. This somehow captures the essence of this article in its fullest. Please carry on reading and you will see what I mean.

It is undeniable that the ability to maintain secrecy has been a consequence of human intelligence throughout the ages. And it will continue to be used for applications and reasons that are manifold.

This science of hiding secrets is called Steganography (stego) and today we are dealing with electronic steganography where we use images, audio and video files [10]. A variety of methods have been used in the past; such as using invisible ink or masking the secret text inside some inconspicuous text [8]. The ancient Greeks used to send secret messages by tattooing the secret message on the shaved head of the messenger. And once the hair grew back, then would send the messenger to the destination and he would have to get a shave again to reveal the secret message. Besides covert communication, stego is also used to protect intellectual property by watermarking the media using digital fingerprints [11].

Steganography has also been showcased in the movies. One example is Tony Scott’s Enemy of the State, which mainly revolves around video surveillance and spying by the US government.

In most instances, one would resort to Cryptography to ensure secrecy of confidential information, whether for communication or storage. And there are a number of useful and very reliable tools/techniques available even to the general public. However ulterior motives have encouraged people to seek alternative approaches and stego has been gaining attention recently.

According to [6], the U.S. government has raised concerns under the suspicion that terrorist organisation using websites and newsgroups to send stego-secret messages. There has also been a reported case of corporate espionage where an employee leaked confidential documents to rival company by hiding it in music and picture files [7]. And more recently, the FBI arrested 10 Russian spies [1] in the US, who used a commercially available stego tool to hide secret messages in images available on websites [3]. This is enough evidence that steganography is being for practical purposes, and is far more superior than cryptography in concealing the secret. Because cryptography/encryption simply makes the secret unreadable, but stego hides the secret and has to be first detected in the first place to retrieve the message [10], thus enforcing what Goethe said. So far, this has been all talk, so lets demystify stego and have a look at what goes on under the hood.

2  Technical Perspective of Image-Stego

There are several techniques used in image-stego; such as using the Least Significant Bits (LSB) of the image, manipulation of image and compressions algorithms, and modifications of image properties such as its luminance [4].

Since LSB is one of most commonly used technique, this will be looked at in more in-depth. Since computers only understand binary data (i.e. 1s and 0s), bitwise operators are used to manipulate the LSB [6]. e.g. in the binary value 10010101, the LSB would be the right most bit. Hence this would be changed resulting in 10010100. This simply results as ordinary noise in the images, which is visually impossible to detect by the naked eye.

The following image by [2] illustrates LSB very nicely. All images have been taken from the his website. Starting from the left, the first image on (a) is the original image, the second image show the LSB enhanced, the third image (c) shows the original image after applying steganography to hide 5KB of random data, and lastly the fourth image (d) shows the LSB of steg-image. The enhanced LSB simply shows the last bit out of the eight bits (each colour pixel has eight bits per colour channel RGB) used to represent the image data, and the first seven bits are eliminated.

Figure 1: (a) Original Image (b) LSB enhanced (c)Original Image with hidden message (d) LSB with hidden message

As it can be seen, there isn’t any visual differences between (a) and (c). However, once we compare (b) and (d), i.e. the LSB, it is easy to detect that something foreign has been embedded in the original image. This example shows a very simple stego-technique to hide the secret. However, there are more sophisticated stego-tools that can be very difficult or impossible to detect.

3  Stego-tools

There are several setgo-tools available. Some commercial and several for free. The following table lists some tools available.

While this is not an exhaustive list, there are several more on the Internet which can be easily revealed by a simple Google search.

4  Detection and Challenges

Security is now paramount in any facet of life and we are living in an age where people are more sensitive and effected by security. Thus there are several security implications due to the growing trend of using stego for covert communication.

Detecting stego, also called Steganalysis, is quite a challenge and while there has been more interest among the research community recently, not much advancements have been made. It has been even a greater challenge for forensic investigators while analysing electronic evidence. This because most of the existing techniques or forensic tools predominantly rely on known stego-signatures (fingerprint left by the stego-tool) or knowledge of the stego-system (i.e. knowing which tools were used or possessing the original cover images, etc.) [9,5]. Thus if the user used a new stego-too/technique which the existing tools does not recognize, then it would not be able to make a successful detection. Much like an anti-virus program not being able to detect a virus without the specific virus definition.

5  Conclusion

Steganography is definitely a very practical and reliable way of ensuring privacy and security of confidential information. And to raise the bar even further, one could encrypt the information before being hidden away in the media of choice.

Several reported cases and also supposed cases are proof that it is already being used and driven by various motives.

References

[1]

CBSNews.Fbi: 10 russian spies arrested in u.s., 2010.

[2]

Guillermito.Steganography: A few tools to discover hidden data, 2004.

[3]

Kelly Jackson Higgins.Busted alleged russian spies used steganography to concealcommunications, 2010.

[4]

N.F. Johnson and S. Jajodia.Steganalysis: The investigation of hidden information.pages 113-116. IEEE, 1998.

[5]

G.C. Kessler.An overview of steganography for the computer forensics examiner.Forensic science communications, 6(3):1-27, 2004.

[6]

R. Krenn.Steganography and steganalysis.Retrieved September, 8:2007, 2004.

[7]

S.P. Phadnis.Data leak: Cyber sherlocks outwit hackers, 2007.

[8]

J. Pieprzyk, T. Hardjono, and J. Seberry.Fundamentals of computer security.Springer Verlag, 2003.

[9]

N. Provos and P. Honeyman.Detecting steganographic content on the internet.Ann Arbor, 1001:48103-4943, 2001.

[10]

B. Schneier.Secrets and lies: digital security in a networked world.Wiley, 2000.

[11]

J. Silman.Steganography and steganalysis: an overview, 2001.

File translated from L^AT_EX by T_TH, version 4.03.

05-JUN-96

Bird must soar. Skunk must stink.
Cat must prowl. Man must think.

What sets man apart from beast is his engine of
thought. His mind. His
BRAIN
makes him unique
and gives him his greatest pleasure.

But fundamental as is thought for human beings,
there is stuff more basic still that underlies and
DRIVES
not only man
but all great beasts,

And that is nature’s call to each of us… to be special.
To be distinguished in some way. To be
UNIQUE.
To BE something, to DO something, BETTER than everyone else.

Like the leather nosed chimpanzee,
dragging noisy cans and branches,
frightening peers into submission,

One does not have to be brilliant, a genius, to be special.
To do something better than anyone/everyone else. To be
UNMATCHED,
One has only to choose an END
any END
that MATTERS
that INSPIRES
YOU
And then DO IT.

source (http://www.cs.cmu.edu/~mblum/research/pdf/grad.html)

Eid prayer in Badhshahi Mosque in Lahore, Pakistan

While we celebrate and eat delicious food on this day, let us not forget about those who are not so fortunate. Alhamdhulillah for everything I have and everything I am to receive.

A women attending to her malnourished child outside a camp in Somalia (August 28, 2011)

LaTex is not for everyone. Most of us who are already very much used to wordprocessors such as Ms Word/LibreOffice Writer, the “point and click toolbar to get everything done” approach cannot be used. Everything is done using special markup or escape sequences of code. However, the benefit is that, you can be assured that the output and formatting is consistent all the time. The file is basically a plan text file, and the LaTex processor handles the processing and generation of the output (either PDF, PS, etc. format). More advantages and disadvantages here.

LaTex does not support Thaana typesetting natively. There are some packages such as bidi or babel that can be used for multilingual/right-to-left language support. LaTex uses packages to add features to the document. Similar to including library at the header when programming. But it wasn’t working out very well for Thaana. So XeTex was the preferred choice. Since I used XeTex for the task in hand, you must be wondering why I have been talking about LaTex all this while. The simple and honest answer is that most of us are familiar with LaTex and we often use it synonymously to refer to Tex style typesetting.

There are plenty of articles about producing documents in LaTex, but none specifically for Thaana/Dhivehi. So after a few hours research, I found out that it is possible to produce a decent document in Thaana. I was pleased with the results, given the nature of typesetting Thaana documents.

Things you would need:

1. LaTex installed and running. Instructions for Windows/Mac/Linux here. When you install the LaTex installation from any of the packages, XeTex will also be installed, along with an editor. I would recommend using the editor, however, you can also use any text editor for creating the document. But then you would have to “compile” the document from command line to generate the output.
2. Install polyglossia and fontspec installed if they are not already installed along with the LaTex. Polyglossia enables the right-to-left support. If you don’t use it, then the output using the standard packages will produce a mirror image for all the words in Thaana script (even if you type it correctly in the editor). Fontspec allows you to specify fonts that are installed on the system such as “Faruma” or any other unicode Thaana font, instead of the standard fonts that are used by default.
3. Make sure your OS (Windows/Mac/Linux) has the Dhivehi/Maldives keyboard installed to allow you to actually type Thaana text in unicode. If you are already typing Thaana in Microsoft Word or LibreOffice, then you’ve probably completed this step.
4. Finally install the Thaana unicode fonts that you like and start creating the document. The font that I’ve used is Faruma.

After completing the above requirements, you would have to place the following lines in the preamble before actually creating the content of the document. These lines tell the LaTex engine to use the polyglossia and fontspec packages, and sets “divehi” as the default language (it’s not a typo, that’s how divehi is spelled in this package) and sets “Faruma” as the default language.

\documentclass{article}

\usepackage{polyglossia}
\usepackage{fontspec}

\setdefaultlanguage{divehi}
\newfontfamily\divehifont{Faruma}
\setmainfont{Faruma}

The following are the source document and the output in PDF format.

• LaTex source file: dhilatex.doc (This file was uploaded with extension .doc, because WordPress doesn’t allow to upload documents with .tex extension. Please download and rename to .tex extension before opening in the editor).

• PDF output file: dhilatex.pdf

As you can see the bullets are alright, but the numbered list shows the “dot” after the number on the wrong side (in left-to-right format). Like I said before, it’s not perfect. Hopefully I will be posting more updates of my future experiments as this looks quite promising.

May your life be brightened up with the Almighty Allah’s blessings of love, joy and good fortune.

Ramadan Kareem

This is a simple control to ensure that you are a human being and not a nasty little program that automatically queries the directory.

I am aware that a few others have come up with small hacks to bypass this or to search through the directory by other means, so this is not what this post is about.

I simply wanted to check how well this captcha control is doing its job in fulfilling its purpose. The object is to challenge so that only a human is able to read and enter the text.

However, using two very simple tools, it is possible to automate the process of identifying the text without the use of a human.

This can be done in two simple steps, 1) perform a simple threshold to get rid of the noise and 2) use an OCR engine to read the text

Thresholding is used to remove the pixels in an image based on the value (e.g. grey-level) specified. You can do this using any image processing application such as Adobe Photoshop or GIMP. But for simplicity I used ImageMagick which has a nice and powerful set of command-line tools that can be used on all platforms (Linux, Windows, and Mac). But before thresholding, I converted the image to a greyscale image, because the original images generated a in blue color.

convert -colorspace Gray input.jpg -threshold 30% processed.jpg

The above command can be used to convert the original image (input.jpg) into the pre-processed image (processed.jpg)

After thresholding, a nice image with very few noise was produced, and this pre-processed image was then passed to an OCR engine to convert the image text, to readable electronic text. For this I chose tesseract-ocr because its simple, easy to use and again available in command-line on multiple platforms. The default language is English.

tesseract processed.jpg output.txt

The above command with OCR the input image (processed.jpg) and create the output in the file output.txt.

For my small experiment, I generated a few captachas from the Dhiraagu E-Directory and saved the images.

The captcha image consists of very clearly written text with several random lines to create a noise effect. So a simple threshold was sufficient and the uniform text made it very easy for the OCR engine to recognize the text.

The following are the results. The results aren’t 100% accurate, but with a few adjustments it would be very easy to make this more accurate. With some work put into it, I bet someone could make a firefox plugin so whenever we visit the Dhiraagu E-Directory, it enters the text for us

Dhiraagu E-Directory Captcha OCR