Excerpt: How High School Math Foiled a Terror Attack on India Gate

Delhi was about to be hit by a terror attack & the Special Cell was struggling to crack a code. Then, a miracle.

(The following excerpt has been taken, with permission, from Chapter 2 – ‘The Da Lakhvi Code’ of the book ‘Khaki Files: Inside Stories of Police Investigation’ – written by Neeraj Kumar. Published by Penguin, the paperback is 256 pages long and priced at Rs 319.)

(The sub-headings are not part of the book, and have been added by The Quint.)

Delhi was about to be hit, innumerable lives would be lost, and the unit of the Delhi Police — the Special Cell — meant to prevent and detect terror strikes, although aware that an attack was imminent, was clueless of the details because it couldn’t crack a code.

Various cryptographers based in Delhi were contacted. Some were in the armed forces, a few others worked in government research organizations, some were in universities and so on. Everyone contacted began to work on the code, but no one was able to crack it quickly.

The intelligence agency we were collaborating with procured decoding software and computers overnight in an attempt to crack the code but to no avail. The next email that came was on 19 February, again from [e-mail] to rashid32XXXX@hotmail. com. It read:

Dear Rashid
Ek naya ID bana lo. Yahin par mujhko iss ID par mail karo. .002 .01 .004 .7 .000 .7 .07 .07 .7 .000 -7
Zaid.
[Dear Rashid, please make a new email ID. Then mail me on my present ID. -------CODED MESSAGE----------- Zaid.]

This email was followed by another one sent a little over an hour later, at 11.46 am, from [e-mail] to [e-mail] stating:

“Dear Rashid naya id yah par nahi hot par hai aap bhi hot par bana lena aur neha ko bhi naya wala de dena aur bolna who bhee naya bana kar mail kare. Zaid.”
[Dear Rashid, the new ID is not on yah but is on hot. You too make your ID on hot and tell Neha to do likewise. You both should mail me on my new ID so created.]

It was not difficult to guess that ‘yah’ referred to yahoo and ‘hot’ to hotmail.

Since the code had not been cracked, the first message was Greek to us. We felt like headless chickens running around trying to decipher the code. There was a gnawing feeling in the pit of my stomach telling me that disaster was about to strike and we would certainly be hanged for it.

Pramod went to the extent of contacting a friend of his based in the US, who worked for a cryptography company, to help us on an urgent basis. The company quoted a price for the job, which was prohibitive but worthwhile considering that many innocent lives were in danger and national prestige was at stake. I met my superior and informed him of the conundrum we were in and the requirement of money in foreign exchange to be paid abroad. My boss expressed his inability to be of any help as the matter required approvals from various levels of the Government of India and that too in a very short time.

‘Sir, I Think I Should Be Able to Crack It’

At this hopeless juncture, when all seemed lost, something providential happened.

On 19 February, when we were clueless, out of our depth and running out of time, a saviour arrived on the scene in late afternoon. He was neither a cop nor a computer whiz-kid nor a cryptologist. He was an unemployed youth who had come looking for a job in Delhi. He had nowhere to go except to Pramod, who had been his senior in school. Vivek Thakur was his name. Vivek could sense that things weren’t right with his schoolmate, who had anxiety writ large on his face. Vivek inquired what the matter was/

Without giving him any background information, Pramod told him that he was struggling with an encrypted message that could not be deciphered. On Vivek’s request, Pramod shared the coded messages with him. Thereafter, Pramod left the office to seek help from diverse sources to decode the messages.

After a couple of hours, Pramod returned to his office, drained after what he felt was another wasted day of fruitless work. He found Vivek still sitting on the visitor’s couch with pen and paper, working on the code. Pramod expressed his surprise on seeing him.

Vivek looked up at him and said: ‘Sir, I think I should be able to crack it.’ Pramod brushed him aside saying a job was not done until it was done. Vivek, however, persevered with the code, mindless of Pramod’s dismissive comment.

At this point, I sent Pramod a message that I wished to see him. I wanted to meet him to review the progress on the case.

The ACP left his office in Ashok Vihar for police headquarters, where my office was located. Vivek wanted to accompany him as he thought that at the end of the forty-minute drive to headquarters, he would have cracked the code.

Reluctantly, Pramod agreed. Throughout the long drive amidst maddening traffic, the two friends did not exchange a word. Vivek remained drowned in thought, scribbling feverishly on a sheet of paper. As they alighted near the stairs of the police headquarters, Vivek, in a eureka moment, let out a muted cry of triumph: ‘Sir, I have cracked the code and it is very simple. It is a combination of binary and decimal systems that our maths teacher in school taught us.’

Pramod began to climb the stairs and heard Vivek out with incredulity.

His friend explained that each letter of the English alphabet had been numbered from .0 to .9, starting with A. The tenth letter was numbered 00, with the decimal point shifting a digit to the left. So, A was numbered .0, B was .1, C was .2 and so on until J, which was numbered .9.

With this method, K was not assigned the number .10 but instead .00, and L became .01, M was .02 and so on until T, which was numbered .09. Consequently, U was numbered .000, V was .001, W was .002, X was .003, Y was .004 and Z was .005. To further clarify, I will put it down more elaborately. The code used for each letter of the alphabet is written below it:

A B C D E F G H I J K L M N

0 .1 .2 .3 .4 .5 .6 .7 .8 .9 00 .01 .02 .03

O P Q R S T U V W X Y Z

.04 .05 .06 .07 .08 .09 000 .001 .002 .003 .004 .005

In some emails, -5 or -7 was written at the end of the code. That meant that while decoding, the reader needed to count back those many letters. For instance, the email dated 17 February read:

Dear Rashid, please make a new email ID. Then mail me on my present ID 002 .1 .004 .7 .09 .7 .07 .7 .000 – 7’.

Using this method, 002 was X, but if we counted back seven letters (as indicated by ‘-7’ at the end of the message), it became P. The deciphered code therefore read ‘purana makan’. It was not surprising, therefore, that emails sent after 17 February originated from [e-mail]. The matching of this email ID confirmed that this indeed was the correct way to decode the messages.

While both schoolmates sat outside my office waiting for their turn to see me, Pramod once again made sure that the decoding formula worked out by Vivek was in order. When Pramod walked into my office he looked triumphant and relaxed. He explained the decoding methodology to me, and we were finally able to make sense of the coded emails.

We then realized that India Gate was going to be the target of an attack, as mentioned in code in the email dated 15 February. The coded message, as stated earlier, was ‘.05 .000 .00 .05.7.03 .7 .0 .4 -7’. When decoded, it read ‘India Gatx’. The last letter was a typo and ‘x’ was meant to be ‘e’.

Therefore, the date for the terror attack was fixed as 25 February and the target was India Gate.