G Balaji's blog

Email obfuscation is broken

2009-10-16T21:33:00.000-07:00

An year and a half back, I was working on some project where I had to parse students' and professors' homepages to mine interesting information from them.
One common underlying pattern I found on their pages, from new grad students' to emeritus professors', was the method of obfuscation of their email ids.
Though they were in the right track on preventing spam bots from harvesting emails and spamming them, the actual way they did it was as insecure as protecting a house by fastening windows but leaving the door wide open. One should remember that people who write spam bots are not foolish. They earn lots of money from collecting emails and selling them to people who do the actual spamming. These trivial ways won't stop them by any means.

There are three popular methods used to obfuscate, each progressively difficult for the spam bot:
1) Just replacing the '@' and '.' characters, like email_id AT server DOT edu.
2) Encoding semantics, like "first 7 characters of last name" AT server DOT edu.
3) Placing the image of the email id.

Any good spam bot can easily extract the correct email id if methods (1) or (2) are used. It just has to have a list of common patterns that people use, and make some string substitution and educated guesses.
Method (3) is extremely secure, but unfortunately it is like a fastened window, where the open door is the URL of the webpage itself.
Typically the students' or professors' pages have URLs with a definite pattern, like cs.university.edu/~emailid or people.college.edu/emailid or emailid.school.college.edu. As you can see, almost all the URLs have email id encoded in them, after all this is how the page itself was created automatically.
From the URL, it is easy to guess the email id. For example, in the third example, the email would be either emailid@college.edu or emailid@school.college.edu.

So, what is the way out? The answer is there is no way out until the schools themselves change the URL naming scheme of the pages they assign to their staff and students.
Till then, the best way is to put the image of the email id and, in addition, route the emails via Gmail, hoping that Gmail will block the spams automatically.

Orinoco

2009-10-13T15:15:00.000-07:00

Yesterday somebody from Microsoft gave a talk on a yet-to-be released product, which was codenamed 'Orinoco'.
The name immediately caught my attention, he explained that Orinoco is the longest river in the world that doesn't have a dam built on it. He further explained how their project got this apt name. Theirs is a database product that processes 'streaming' events, that is, certain events like web-page visits or stock numbers come to their servers in a continuous flow (like the river), but instead of storing all the values (the dam) and then processing them, they efficiently compute and return necessary results instantaneously to whoever requests it.
I thought that it is definitely a neat name, coming from a company that names its products as 'Microsoft Windows Genuine Advantage Professional Edition Service Pack 2' (or even oxymoronic 'Microsoft Works', as the popular joke goes).

But toward the end of the talk, he revealed that the name of this product would be changed to 'Streamlight' in keeping with Microsoft's newer Web 2.0 naming schemes such as 'Livemesh', 'Silverlight' and 'Autocollage'. I feel these names are still better than the ones Linux community comes up with, which is either recursive acronyms or dotted version number schemes.

PS-1: I found the recursive acronyms to be cool when I first heard about them 7 years back. But now I am just fed up that people cannot come up with creative new names.
PS-2: Microsoft has named one of its products as XNA, which stands for 'XNA's Not Acronymed'.

Two weeks' notice

2009-07-17T23:04:00.000-07:00

Today I attended a class by the vice president of global talent acquisition on improving interview skills. I was happy that I already knew most of what he talked about.
Sometimes, to validate yourself that you really know a thing requires to sit on classes that teach those things.
Anyways, so he was giving examples on questions not to be asked in an interview. You know, the questions that pertain to age, gender, family, health, orientation, etc.. In one example, he quoted a line from the movie 'Two weeks' notice' starring Hugh Grant and Sandra Bullock, where Hugh, in one of his interviews, mistakes the girth of a fat lady to pregnancy and blurts "congrats for the baby". The interviewee becomes agitated, and Sandra gets worried that this may lead to a lawsuit. Hilarious scene, he says.
So, he was giving this as an example, and I saw many people in the audience were nodding. Hmm, how come I have never seen this movie, I wonder.
And guess what, by sheer coincidence, in my dinner, after randomly switching channels, I land up on one that airs this very movie and watch the exact scene while having my dinner!
Whats the probability of this happening?
1/8,000,000 I would say.

Madison Student Optimizes Physics

2009-04-24T16:19:00.000-07:00

N Orchard Street's greatest physicist, Dr Dchongesh, today accomplished an extraordinary thing that will surely change the way we think of the world (and of him).

Dchongesh after pwning Einstein's formula.

Dchongesh, an ardent fan of Djokovich and Deborah Djosheph, today proved that Einstein's mass-energy relation is sub-optimal. When our staff reporter asked him about his latest finding, he replied "When I first saw the equation E=mc², I was like, 'Dude, there has got to be a more efficient equation for this. Everybody know that quadratic running time won't scale for large c's. I then worked all night, constantly referring to my borrowed copy of 'Introduction to Algorithms', and finally derived my optimized equation E=mc*log(c) that would perform 30% better in parallel processors".
But when our unconvinced reporter asked if he could just optimize nature's laws just like that, he replied "Dude, who is taking CS587-Algorithms course, you or me?".

Meanwhile, Nature is unsure how to react to this sudden change in physical laws. But people in 45 N Orchard St are positive that the new optimized physics can help in reducing global warming, controlling weather, increasing TAships, getting dates, and decreasing the frequency of nature calls that they are experiencing now.

Irrational Interviewers

2009-04-17T22:00:00.000-07:00

Sometimes knowing too much might be disadvantageous. This always seem to happen to me during interviews, where I almost always have heard of the problem and know the solution. Most of the times I would have solved the problem myself, but then, I cannot give a proof of that to the interviewer.
And most of the interviewers come prepared with only a bunch of questions, and when I tell them that I already know the solution, they are at a loss of what to do, and most of the times ask me to proceed with the solution I know (hoping that I will give a sub-optimal/inefficient solution, and they can take pleasure out of saying "is there a better way of doing this?").

This act of honesty from my part is rarely appreciated. Most of the times it is taken negatively, and I suppose in the feedback they would write "he already knew the solution, and only hence he could solve it" or "even though he knew the solution, his code contained a bug" etc.

In my very first job interview, I was asked the famous puzzle where one person always lies and the other always speak truth, and I politely let them know that I already knew the puzzle (but I dint tell them that I knew it since I was in 7th grade!). Two other interviewers laughed at the interviewer who asked the question, making him look like a village idiot! I don't know why they did this, but this made that interviewer a bit animus towards me from there on. Anyways, I was offered the job next day.

Again this happened to me last month also, and to make it worse, the interviewer did not come prepared with back-up questions (he asked the same question to my friends later in the day, and who, thanks to me, got it right). He then mailed me later, saying I was not technically qualified! If already knowing an answer makes one technically unqualified, then why do we even have exams!

One doesn't even get brownie points for being honest.

Needless to say, it again happened on an onsite interview last week. But this time, I did not remember the solution to the question asked, but I did remember that I had solved the problem before. There I made some mistakes while re-solving the problem (maybe because somehow I felt bored on tackling a tamed beast). Because of these small mistakes, the interviewer asked me to stop there and deviated to talk about, among other things, what I think of their competitor (as usual, I gave him my honest opinion, which immediately made him stamp a "unfit for this project" seal on my resume).

Not surprisingly, it happened yet again two days after the above incident, and here too, I cleanly told them that I already knew the question. This interviewer was well prepared. He had come with three backup questions.
And I knew all them before.

But this time, I was offered the job, and that too the very next day.

As an interviewer, I once interviewed an undergrad who knew the answers to all my questions (even the backups). The questions were very difficult (one that I remember asking is: to compute the Nth Fibonacci number in only log(N) steps), and I was impressed that he knew the solutions for these. This means that he has made an effort to learn more and has tackled hard problems. Doesn't matter if he already knew the answer, the questions were so hard and rare that only a true connoisseur of algorithmic problems would know these. I went one step further and made the problems even harder (like for the above problem, I modified it to find Nth number in a generalized linear recurrence in log(N) steps), and was satisfied that he could solve those even though he hadn't heard of these versions before.
I mentioned this in the 'candidate feedback', and after two days, got a mail from company's Vice President saying "if a candidate already knows an answer, ask a different question!", and the candidate was put on hold for further interviews.
I don't know what happened to him, sad that he was honest, and my bad that I tried to see how deep he understood that problem, instead of moving over to a new one.

Note: the labels for this post are not for stuffing keywords and increasing my pagerank. Those are the companies that interviewed me (or I have taken interviews for them) that are mentioned in this post. They are arranged in random order purposely.

Papers are People Too

2009-03-29T16:41:00.000-07:00

This is the poster for a hypothetical movie called "Papers Are People Too"^* that I made for the Earth Day and sent to my friends to make them cautious about the overuse of paper generating machines (printers and photocopiers).
I also sent them a snippet of the story for the hypothetical movie. The response was pleasantly positive, they claim to have decreased the number of printouts they take, and it seems to have given them happiness also.
I am pasting the snippet below:

Papers Are People Too
The plot:
"Our hero GeeBee studies in a college where he is given unlimited supply of paper and free printouts.
So should he care whether all the 100 pages he is just going to print will be read by him later?
Should he strain his eyes to read a PDF instead of just hitting <Ctrl + P>?
He knows very well that decreasing the font size and removing images would print the html content in fewer pages, but is it worth all the hassle?
Why bother placing unwanted papers in the recycling tub when he can just throw them away with kitchen trash?"

The cast: You and me.
Releasing on the Earth Day next month.

One thing that I silently slipped in, in the poster, is the fact that we don't bother to give a name to a tree, even if we have been brought up seeing it in our yard all the years, but we tend to give a name to every other pet that we come across.
This was at the back of my mind, and that is the reason for the lines at the bottom of the poster (you may have to scroll to see them).

^* The title inspired from the blog Papayas are People Too.

The case of self-referring paper

2009-03-01T18:29:00.000-08:00

I was just reading a technical paper for my mid-term exam. The image in the right is of the "References" section of that paper. The underlined sentence states that the papers numbered 4, 9 and 14 in the References section are not cited. But isn't this line itself a citation of these papers, making the statement contradict itself? Moreover, what if one of those referred papers is the main paper itself? The statement would mean that this paper doesn't refer itself, but saying so, it has referred itself!
Furthermore, if I write a paper having a list of all the papers that do not refer themselves, should I include this very paper in the list?
I should, because if I don't, then it doesn't refer itself, hence becomes eligible for entry.
But if I do, then I have referred it in itself. Hence I should remove it now... But then I can't because... so on.
Where is the paradox?

Local boy to change his name after shelving PhD plans

2009-01-15T19:36:00.000-08:00

From our reporter in Madison, WI -
"I always dreamed of completing my PhD", reflects Sabareeshh, an ardent Himeshh Reshammiya fan and a long-term resident of 45 N Orchard Street. In his continued statement, he further revealed that he also always dreamed of people addressing him as "Doctor Sabareeshh", and plans to file a request with the Office of Name Changes to enable him achieve his aforementioned ambition since he no longer has hopes of completing his PhD and becoming eligible to be called with the aforementioned name. But is it a normal thing to do?

"Why not? If people can have names like 'Major Soundarrajann', 'Padmashrii Universal Hero Kamal Hassann' and 'Slave Mistress Vidhhya', whats wrong with changing my name to 'Doctor Sabareeshh'?", he logically argued his proposition before breaking away to check out the ladies section in Walmart.

Meanwhile another local boy DMaheshh, a fierce fan of both Djokovic and Himeshh, rechristened himself as Chongeshh to match with his Chinese girlfriend Chong, who unknowingly in parallel changed her name to Abhitagujalambal taking it to be a cool Indian name. When we last heard, he was in a dilemma on whether to change his name to Abhitagujalesh to match again or to change his girlfriend.

As per a latest update, an application by the Office of Name Changes to change its own name was rejected by the same office, as it would cause infinite recursion of name changes leading to a stack overflow condition.

Shiver me timbers

2008-12-30T07:57:00.000-08:00

Noon in Madison, Midnight in ChennaiIt is inhumanely cold here in Madison. I began to appreciate the etymology of the phrases like "cold as hell" and "hell freezes over" only after experiencing the cold-blooded winter first-hand. My friend gave an interesting explanation that in our cultures we associate hell with a very hot place as we seldom encounter such fiendishly cold climate and are more accustomed to the extreme hot conditions.

After living in hot and humid Chennai for more than 18 years, I initially got cold feet on coming to Madison. But nevertheless I decided on coming because the university here is one of the best in the world, even though it had cold shouldered me two years back. Thankfully, the transition to such a stone cold place was very smooth with the help of three warm-hearted people: Siva, who gifted me all his winter wear starting from the woolen cap to the snow boots, Piramanayagam, who graciously hosted me in his place for more than two weeks, and the doctors at the University Health Clinic who made it mandatory for all students to take a flu-shot (injection for preventing cold and cough) without which we would have suffered from all sorts of diseases due to climate changes.

The picture to the right shows the temperatures of the cities when it was noon in Madison and midnight in Chennai. Madison is creeping cold by more than 40 degrees even during the coldest part of the day in Chennai. The symmetry in the date-time (21/12 - 12 pm) and the temperatures (-23° and 23°) is very striking. Also notice that the temperature is sub-zero in both F and C scales, and being able to endure extreme temperatures from +45° to -25° celcius give me more confidence in reacting to any cold calls from Mother Nature.

Losing Our Identity

2008-10-27T17:53:00.000-07:00

Yesterday the Indian Students' Association of Madison organized a very beautiful event as a part of Diwali celebrations. It was very well conducted and almost all the Indian families in Madison attended and enjoyed thoroughly.

But one thought worried me and kept nagging me on the back of my head.

Are we losing our rich tradition?

How can we forget our past, ignore our traditions and curb our instincts just because we are in a foreign country!

Ok, coming to the point, I was very disappointed yesterday with my fellow citizens:
There was no breaking of queue, no elbow-pushing, nobody went for stealthy second servings (except my friend and me), no spilling of food on tables and carpet (and wiping hands on other person's shoulders when he is looking away) and above all, no spitting on corners of the wall!

Where have all our manners gone?
Why have we suddenly become cultured and well-mannered, like "them"?
We are losing our unique identity.
It isn't all fun when everybody behaves well, just like it is boring to be a gentleman all the time...

That living things...

2008-10-08T18:33:00.000-07:00

That greenish-black lizard with no tail which hangs around in our pooja shelf,

the cockroaches that reside between my books, and which were at least as old as me, and would have chewed more information than I ever did,

those mice that always used to find our house even after letting off from the mousetrap near the railway tracks,

that squirrel which took its maternity leave on our paran and produced two more small ones along with the increase in decibels of noise,

that timid hutch dog, which went for its daily morning walk along my house,

those kittens which stayed in my garage till they realized that I don't stock milk in my house,

and me,

who never realized that there were more living beings which were part of my life, and how subconsciously I enjoyed living amongst them ...

Visa Experiences (Part Two)

2008-08-10T18:56:00.000-07:00

This is the part two of the previous post on my Visa experiences.

Unfortunately I have forgotten most of what took place that day on my visa interview. But what I do remember is people who were extremely hesitant while answering, or who contradicted themselves, or who blabbered something irrelevant to the question asked were immediately rejected.

This does not mean that if you take your time to answer because you are not fluent in English, you will be rejected. No. To give an example, a student going for his MS found it difficult to speak without pausing because he was actually double checking if he heard the officer right, and translated the answer from his language to English. But seeing his face, body actions, and probably his eyes, the officer could very well judge that he was telling the truth.
When you tell the truth, you have nothing to remember and the mind is free of other things. But when you lie, you are preoccupied with the thought of getting caught. Agreed that some glib liars cannot be identified, but then, that is what the Visa officers are trained for. They (and we) can very well distinguish people who speak the truth and those who make up stories on the fly.

Appear confident even if you are not. Smile at them and keep eye contact. Do not revise your pre-prepared answers just before your turn. Let the answers come to you on their own.
This does not mean that you shouldn't be prepared. You should definitely do your homework, anticipate the questions and have an answer for them.
But do not memorize those answers like Kameshwaran does in Michael Madhana Kamarajan. Reply in your own words. Even if you are not fluent in English, its ok, even Rajinikanth is not fluent in Tamil.
Being earnest is more important than speaking fast.

Will Miss You, Prof Randy Pausch

2008-07-27T07:55:00.000-07:00

It was a big shock for me to see the post in Google blog about the demise of Prof Randy Pausch.

Even yesterday (the day he died of acute cancer), I was speaking about him and his extraordinary qualities to my friend, and urged him to watch his video, which I described as "better than the Steve Jobs' Stanford speech".
Three days back, my cousin had gifted me a book version of Prof Randy's famous Last Lecture. The book had many extra chapters which he could not cover in his speech. I was totally engrossed in the book, couldn't turn my mind to anything else. Reading the book, I felt that he is the Feynman of our generation, and the book surely equals the classic "Surely You're Joking Mr Feynman", the only difference being this one is a lot deep and heavy.

Prof Randy's speech was an inspiration to millions of people. He delivered this humorous, witty and philosophical speech knowing that his time was almost up. See the comments posted for his videos, he has changed the attitudes of millions of people single-handedly.

I haven't finished the book yet and I don't know how I will be able to read the book further, with this lingering thought in the back of my mind that the person who took such pains to inspire others and who was the beacon of integrity, is no more...

Visa Experiences (Part One)

2008-06-12T07:00:00.000-07:00

After months of feverish anticipation and tense prayers by my family and friends, the Great Embassy has at last given me the Visa Power, but only after becoming thoroughly convinced that I am capable of using my brains and won’t resort to washing dishes and thus stealing the coveted jobs from the natives.

This was the third time I had stood before the Great Judge, wearing the same set of neat ironed clothes that I had worn for my second appearance, but unfortunately, not for the first. And each time I attended the Great Interview, I had a different frame of mind.
In the first occasion, I was a bit curious. I wanted to find out what really the glorified process was all about. In the second, I was a little anxious as my previous one did not leave any pleasant memories.
In the third, it was plain indifference, because by now, I had lost all my faith in the whole Great Process.
Actually I had lost all faith in myself.
I deemed myself incompetent to make a case and convince anybody. I started believing that I could never argue and defend my stance, and thus would be rejected by the Great Judge.

But one person who did not lose faith in me was my father.
For many weeks, my dad did some heavy browsing in the internet to figure out the application and interview processes for getting the Great Visa. He roamed around in Chennai’s hot sun to arrange all possible documents, 45 in all, and which the Great Officer might ask and would invent a reason to deny the Visa if not present.
He took printouts of umpteen blogposts and made me go through all them. Many of these posts were written by students who had actually attended the Great Interview only once in their life but regarded themselves as an expert consultant. Nonetheless, these were interesting and good in demystifying the process.
I would never have managed to do such an excellent preparation for the interview like my dad did. But for him, I would now be standing in front of the Embassy, in scorching sun, waiting for the security guy to call me in …
for the fourth time …

~ End of Part I ~

In the next part, I will write about how I spent my one hour standing in the queue before the Visa counter and played a game of being the Great Officer and correctly predicted who all will be issued the Great Ticket.

Let there be light

2008-05-19T10:43:00.000-07:00

Twin Color Chakra Tingy Green Blade Red Hot Finger Mercurial Blue Tip Alien Green Eye Metallic Plate Lines Billion Color Band Shining Hope Ray Deep Sea Photons Rising Golden Threads

The photos were taken by me from my cell phone camera (W810i), with sunlight falling on the DVD.

Behind "Coffee With Bandar"

2008-04-19T07:00:00.000-07:00

I heard that many of you who don't follow Sundar's blog (i.e. everybody), had a difficult time understanding my earlier post on his way of taking interviews.
So to give you a bit of background on his blogging style, let me now re-tell his interview with me:

The following transcript appeared as Coffee with Bandar* here.
* Note: No animals were harmed during the making of this post. No coffee was wasted either, only time and energy were.

Sundar's blog is read all over our office.
The truth is nobody here could possibly ignore his blinding status messages, bolded and underlined signature in the mails, or his frequent and loud utterances of "make sure you read todays awesomely popular post in coffee-with-bandar dot com" punctuated in the middle of every conversation.
Hence I decided to have a small chat with him on why he is, well, so annoying.

Me: Mr. Bandar, how do you generate so many ideas for all the boring posts that you put in your blog? Do you read a lot?
Bandar: Yes, I do! Even last week I read the story of Three Little Pigs. But those are not the places from where I get ideas. I do pure research!
You see, I like to provide my audience with only quality content synthesized from hand picked blogs, so that they don't have to waste their time on them and instead waste the cumulative time reading my blog.

Me : But what you do, sounds like plagiarism!
Bandar : No, it shouldn't, because I have never heard of that word.

Me : Duh! Okay, How many page views do you usually get everyday?
Bandar : It ranges from zero to a few thousands. Sometimes when I am very bored, I continuously reload the page till the pageviews reach the three figure mark.

Me: Seeing your hit counter, it seems that you get bored very often...
Can you reveal to us how many unique visitors are there who have no work and don't care for their soul and actually read your blog?
Bandar: Well, it is a secret. Including you and me, the total count has now surpassed 3.
The third being my alter ego. Actually thinking of it, if I could teach my dog to read, it would increase the count by 43% !

Me: Wow, thats great!
Ok, I would like to put a graph of these stats. I am opening up Analytics in my browser, can you login ...
Wait a min! Whats that ugly thing doing in my Firefox?
Bandar: Thats my coffee-with-bandar toolbar! I just installed it in your browser when you were distracted by the mole on my left cheek.

Me: Holy monkey (no, not a racial abuse)! What do you need a toolbar for?
Bandar: The toolbar basically takes screenshots of all the pages that you visit and mails them to me. This way I can analyze what my readers really like and write posts on that.

Me : But it sounds scary. Is it secure? Are you sure it wont spread any viruses?
Bandar : How can it when that itself is a virus! He he he.

Me: Hmmm, you seem to think very deep. Do you consider anybody as a role model?
Bandar : No, None at all. In fact, apart from gastroenteritis, I am in perfect health.

Me: I think you got confused here. I asked if you emulate somebody…
Bandar: Oh yes, I truly admire Miss Teen Carolina! She is my mole mode, errr.. super model, oooops, role model. I am already emulating her in my blogs by writing nonsensical stuff...
Someday I wish to have a chat with her over a cup of coffee and would blog about it. Don't miss that post!

Me: Sure, and many thanks for doing this mokkai interview with me. Hope my readers stay bored after reading this.

A Quick Reference for "Coffee with Bandar"

2008-04-17T09:25:00.000-07:00

If you are an ardent follower of "Coffee with Bandar" posts, you would often want to know what exactly goes into the mind of our genius reporter, Mr Bandarrrajan, when he poses his trademark questions to the "famous" celebrities.
Many times you would wish for somebody to explain the deep and hidden meanings behind those intellectual conversations.
Sweat no more, for I have compiled a quick reference guide for the three most repeated phrases that Mr Bandar uses in all his interviews.

Phrase 1: (Bandar to his readers) "I welcome our super ultra special guest for today who needs no introduction...".
What Bandar really means:
"My bulk mails to people who are really famous did not fetch any response. So I have to now resort to interview everybody who is anybody in my vicinity, who then grudgingly replies in one liners with smilies put at the end of each sentence to pass off as "cool" answers.
(Scratching his cheeks) I should do something about the mole in my left cheek, it seems to put off people..."

Phrase 2: "Hi [interviewee name]. Hearty welcome to this really special edition of CWS".
What really goes in the mind of the interviewee:
"What the heck is CWS? Why am I here? I shouldn't have agreed to answer his stupid questions for the sake a free cup of coffee.. I must first kill that NIT junior of his, who set me up with him. I wish Bandar's gastroenteritis would get severe and burst him out now."

Phrase 3: "What message do u want to give to the budding younger generation of readers who are at present not wasting their time by reading my blogs?".
What Bandar really means when he says this:
"Thanks for your banal replies to my canned questions. Even my dog which reads my blogs, would have got bored of it.
Heck, now I have to reload this post more frequently to make up for the page views lost due to this junk interview..."

What the interviewees really think when he says this:
"Holy grass! You must be really stupid to think that your readers (all three of them) are eagerly awaiting for my advise with bated breadth and yearning to follow it.
In fact, I would advise them stop reading your posts and explore other harmless methods of self torture."

PS:
1) Apparently Mr Bandar tried to take an interview of Blogger's product manager at Google, who then promptly quit his job and moved to Alaska to avoid meeting him. We will miss you Eric!
2) Don't forget to take a micro-xerox of this cheat sheet and keep in your pocket for ready reference; you may never know when Mr Bandar may catch you and force you to read his blog.

First post

2008-04-15T02:52:00.000-07:00

Jai Sri Ram