## Friday, March 28, 2014

### Global Cafe this week: Japan - a country of sushi eating samurai

Global Cafe is a very interesting weekly event held at International Center of Purdue University on Friday from 5.30-7.30 PM where students from a particular country can present about their country, culture and importantly share an authentic dish of the country with the attendees.

Today, the Japanese students association did a session on Japan. I am writing down some of the interesting and new things I got to know here.

Japan is a small island with a very high population. Sushi is considered as the most favorite food among school children. Washoku is the traditional meal served in traditional restaurants which includes a soup and about 3 side dishes. This is considered as an intangible heritage by UNESCO.
Takikomi Gohan is another popular Japanese rice dish which they shared with us today. It was delicious and following is a picture I took before I start eating it. :)

They clarified the actual meaning of Otaku which means a person who is dedicated for a certain hobby or a favorite activity. I also heard for the first time that Japan is famous for anime. It might be my ignorance that I haven't heard it before. They showed some famous animations and also an video of real people who mimic cartoons. Anime Otaku are the people who are into animations.

Geisha is traditional female who entertain visitors in traditional restaurants. But they are not prostitutes as interpreted by some movies. They wear traditional Japanese dress and it needs lot of practice to become Geisha. Apprentice of Geisha are called Maiko. Geisha are not seen by general public and their performances can not be recorded or taken photographs of where as Maiko can be seen by public. Cost of visiting such traditional restaurants where Geishas are, is very high.

Budo is different kinds of Japanese martial arts such as Karathe, Judo etc. Some say that Budo descend from Samurai-who are the warriors in ancient Japan. But it is a both yes/no question. Budo is not to hurt anyone else but to overcome one's own self.

They also clarified the difference between Ninja and Samurai. Ninja are the people who were considered as messengers employed in spying etc. They usually carry a small a knife like tool where as Samurai are the real military warriors who carry the traditional samurai sward. But once the Samurai was prohibited in Japan around 1867, currently people have only the dream of becoming a samurai because they are very attractive.

So above is just a glimpse of what I learned about Japan from today's session most of which are new to me and I hope to explore more about certain aspects such as Japanese cuisine etc.
Looking forward to do a session on Sri Lanka with the Sri Lanakan friends in Purude. :)

## Tuesday, February 4, 2014

### Presenting Algorithms/Protocols in a neat way using Latex

Latex is a very useful tool for scientific writings. It has many cool features to present our writings in a neat manner. I use the TeX Live version of Latex on Ubuntu and I am going to describe how to present algorithms/protocols which contains different steps using the algorithm and algorithmic packages of Latex.

If these two packages do not come with the default installation, you need to install algorithm.sty and algorithmic.sty files to your local installation or you can just place them in the folder where you have the latex file you are currently writing.

First let me show an example output of the latex script which uses the above two packages:

As shown above, algorithm and algorithmic packages take care of all the details such as putting a border around the algorithm/protocol, including a topic for that, numbering the steps with precise alignment and breaking the steps even across several lines without affecting the alignment and numbering.

Following is the Latex script to get an output as above:

1. First you need to include the two packages with \usepackage command as shown below:
\documentclass[a4paper,11pt]{article}
\usepackage{algorithm}
\usepackage{algorithmic}


2. Then you can use the actual script which produces above output using the two packages as shown below:
\begin{algorithm}[H]
\floatname{algorithm}{Attack}
\renewcommand{\thealgorithm}{}
\caption{Steps that Mallory follows to obtain key K}
\label{protocol1}
\begin{algorithmic}[1]
\STATE $M$ : Eavesdrops the protocol 1 above and gets $X$ from step 1 and initiates the same protocol with $B$, by substituting $X$ for $K$ above.
\STATE $M\rightarrow{B}$ : $P = E_{B}(S_{M}(X)) = E_{B}(S_{M}(E_{B}(S_{A}(K))))$
\STATE $B$ : $V_{M}(D_{B}(P)) = V_{A}(D_{B}(E_{B}(S_{A}(X)))) = X$
\STATE $B\rightarrow{M}$ : $Q = E_{M}(S_{B}(X)) = E_{M}(S_{B}(E_{B}(S_{A}(K))))$\\
Since the same key pair is used for both encryption and signing, $S_{B}(E_{B}(message)) = message$\\
Therefore, $Q = E_{M}(S_{A}(K))$
\STATE $M$ : $D_{M}(Q) = S_{A}(K)$
\STATE $M$ : Since the same key pair is used for both encryption and signing, $E_{A}(S_{A}(K)) = K$. Mallory can obtain the key $K$ in this way and decrypt all the subsequent messages encrypted with key $K$.
\end{algorithmic}
\end{algorithm}


[H] in line one specifies to include this algorithm in the current position itself without floating to somewhere else in the document.

Line 2 customizes the name used to categorize these set of steps: you can name it as 'Algorithm', 'Protocol' etc. Here I have used the name 'Attack', since this describes an attack scenario.

Line 3 also customizes a default command in the package by specifying not to number this particular piece of writing. In a research paper, when you have several protocol/algorithm listings, you might need to number them as you want. This command allows to customize that numbering in the way you want, by specifying whether to use Roman numbers, Arabic numbers or letters.

Line 6 specifies style of numbering you need to number the steps of the protocol/algorithm. You also can opt out numbering by leaving the brackets blank.

As shown in Lines 7 and below, each different step in the protocol needs to be preceded by the command \STATE to differentiation and numbering of each step in the protocol.

That covers all the features need to obtain an output shown at the beginning of the post. Hope this helps.