Avil Page (Posts about musings)

Cube & Cubicle

Anand Reddy Pandikunta — Thu, 31 Oct 2024 03:35:37 GMT

Rubiks Cube

When I was in college, I was traveling to a friend's place and missed bus at midnight. The next bus was at 4 AM. While I was bored waiting for the bus, I found Rubik's Cube in a shop.

I scrambled the cube and spent the next 4 hours trying to solve the cube. I managed to solve one color. When I tried to solve the next color, the pieces in the previous layer started missing.

Even after spending a lot of time in the next 3 weeks, I couldn't solve it and gave up.

After a couple of years, when I "learnt" about the internet, I searched and found simple algorithms to solve the cube. Within a few days, I was able to solve the cube in a minute.

Office Cubicles

In the final year of college, there were placements. When I was preparing resume, I included "I can solve Rubik's Cube in a minute" in it.

During the interview, interviewer asked me if I can really solve the cube in a minute. He asked me to get my cube and show him during the lunch break. I did. Luckily, I got hired.

Even though, I was hired for Wipro I didn't join. I went to Bangalore and started applying for start-up jobs.

I went for an interview at a web development company in Malleswaram, Bangalore. The CEO looked at my résumé, took out a cube from his desk. He handed the cube to me, showed an empty cubicle behind me and said, "If you solve the cube in a minute, that cubicle is yours."

Just by learning the cube, I was able to land a job an at an MNC(Multi National Company) and a startup as well.

Midnight Coding for Narendra Modi & Ivanka Trump

Anand Reddy Pandikunta — Sun, 18 Aug 2024 00:25:43 GMT

Introduction

In 2017, GES Event was held in Hyderabad, India. Narendra Modi (the Prime Minister of India) & Ivanka Trump (daughter of the then US President Donald Trump) were the chief guests.

At that time, I was part of Invento team, and we decided to develop a new version of Mitra robot for the event.

The Challenge

We had to develop the new version of Mitra robot in a short span of time. Entire team worked day and night to meet the deadlines and finish the new version.

We went to Hyderabad from Bangalore a few days before to prepare for the event. We have cleared multiple security checks, did some demos for various people before the event.

A day before the event, around 9 PM we discovered a critical bug in the software. Due to that bug, the Robot motors were running at full speed which was dangerous. If the robot hits someone at full speed, it could cause serious injuries.

I spent a few hours debugging the issue and even tried rolling back a few versions. Still, I couldn't pinpoint the issue.

Since we need only a small set of Robot features, we decided to create a new version of the software with only limited features. I spent the next few hours creating a new release.

After that, we spent the next few hours doing extensive testing to make sure there are no bugs in the new version.

It was almost morning by the time we were done with testing. We quickly went to hotel to have some rest and get back early for the event.

Conclusion

Mitra robot welcoming Modi & Trump went very well. You can read about Balaji Viswanathan's experience at GES 2017 on Quora¹.

Answer on Quora ↩

On Resuming Writing Challenge

Anand Reddy Pandikunta — Wed, 19 Jan 2022 00:36:06 GMT

Photo by Kaboompics on Pexels

In 2018, I decided to write at least one blog post per month throughout the year. Even though I tried to write posts every month, I couldn't publish anything in few months.

In 2019, I went a step ahead and made a legal(?) agreement with a friend. I paid him 1,00,000 rupees (~1,200$) and told him that he could keep the money as a reward if I failed to write a blog post every month.

This agreement kept me on my toes. I didn't miss writing a single month in 2019. I stayed awake on the last days of the month to finish and publish the post before midnight.

In 2020, I took up the challenge again and I was able to write at least one post every month.

In 2021, I didn't take up the challenge. I wrote just three posts in the entire year.

In the two years when I took the challenge, even though I wrote a few mediocre articles, I wrote a few good articles. In the other two years when I didn't take the challenge, my writing quality and quantity declined.

Due to this, I decided to take up the writing challenge again this year.

Instead of limiting the 1,00,000 reward to my friend, I decided to extend it to all the readers.

The first person who calls out that there is no new blog post in a month will get the 1,00,000 reward. The next three people will get a small gift as a token of appreciation.

I will try my best to write at least one post every month. Let's wait till the end of the year and see how it goes.

A Typo Got Me $100 Bug Bounty

Anand Reddy Pandikunta — Mon, 25 Oct 2021 03:22:19 GMT

Introduction

On a lazy evening, while on a call with a friend, I made a typo while entering the url. Instead of typing http://app-00421.on-aptible.com, I typed http://app-00412.on-aptible.com¹.

In this article, lets see how this typing mistake got me a bug bounty.

Vulnerability

A bug bounty program² is a deal offered by companies by which individuals can receive recognition and compensation for reporting bugs, security exploits and vulnerabilities.

Aptible provides HIPAA³ compliant PAAS platform so that healthcare companies can deploy their apps without compliance hassle.

After deploying an application on aptible, users can create an endpoint for public access. For this purpose, atpible generates domain names in sequential order.

Due to this, a set of publicly exposed servers will have incremental domain names. A lot of companies use these sequentially generated domain names for staging & testing purposes. In general, many companies don't bother about implementing security best practices on non-production servers.

When I was trying to access a demo site at http://app-00421.on-aptible.com, I made a typo and visited http://app-00412.on-aptible.com. This site was a staging site of some other company without any authentication. The company's source code, AWS keys and a lot of sensitive information was publicly accessible.

I quickly emailed that company regarding this issue and they took their site offline. As per Aptible disclosure policy⁴, this bug is out of scope. Howev er, I sent an email to their team regarding the severity of the issue. Since sequential domain names are generating additional target surface for attackers, I suggested to move to random urls.

For this disclosure, they have provided a bounty of 100$ and Aptible decided to move away from sequential domain names.

URL has been changed for anonymity. ↩
https://en.wikipedia.org/wiki/Bug_bounty_program ↩
HIPAA - Wikipedia ↩
https://www.aptible.com/legal/responsible-disclosure/ ↩

Why My Grandma Can Recall 100+ Phone Numbers, But We Can't

Anand Reddy Pandikunta — Thu, 20 Jun 2019 15:51:21 GMT

On a leisure evening, as I was chit chatting with my grandma, my phone started ringing. Some one who is not in my contacts is calling me. As I was wondering who the heck is calling, my grandma just glanced at my screen and said, "Its you uncle Somu, pick up the phone". I was dumbstruck by this.

Later that evening, I asked my grandma to recall the phone numbers she remembers. She recalled 30+ phone numbers and she was able to recognize 100+ phone numbers based on the last 4 digits of the mobile.

That came as a surprise for me as I don't even remember 10+ phone numbers now. Most of the smart phone users don't remember family and friends phone numbers anymore.

A decade back, I used to remember most of my relatives and friends phone numbers even though I didn't had a phone. My grandma used to use a mini notebook to write all the phone numbers. I was worried about this mini notebook as it can get lost easily and it is always hard to find when required.

Since my grandma didn't have any contacts in her phone, she gets a glimpse of number every time someone calls her. She also dials the number every time she has to call someone. With this habit she is able to memorize all the numbers.

I, on the other hand started using a smart phone which has all the contacts. I search my contacts by name when I have to dial someone and there is no need to dial the number. Also whenever someone call me, their name gets displayed in large letters and I never get to focus on the number. Due to this, I don't remember any of the phone numbers

After this revelation, I started an experiment by disabling contact permissions for dialer app. With this, I am forced to type the number or select appropriate number from the call history and dial it. This was a bit uncomfortable at first. Soon I got used to it as recognized more and more numbers.

This might seem unnecessary in the smart phone age. But when you are traveling or when your phone gets switched off, it's hard to contact people. Even if someone gives their phone, it is of no use if I don't remember any numbers.

Also it is important to remember phone numbers of family and friends which might be needed in case of emergencies.

How BMTC Is Exploiting Crores From Bangalore Citizens?

Anand Reddy Pandikunta — Sun, 05 Feb 2017 17:08:16 GMT

BMTC (Bengaluru Metropolitan Transport Corporation) is a government agency which operates the public transport bus service in Bangalore, India. It holds monopoly as it is the only choice for public transportation.

Fare Calculation

BMTC considers ~2KM distance as a stage and the fares for each stage are as follows.

Let's say, you want to travel from Indira Nagar to BTM Layout, it will cover 5 stages. So, BMTC charges 19₹ for that.

Exploitation?

If you travel from Indira Nagar KFC signal to Doopanahalli Arch(1.2KM), which comes under 1 stage, you have to pay 5₹.

On the other hand, if you travel from Indira Nagar KFC signal to Doopanahalli bustop(1.4KM), you have to pay 12₹.

How can BMTC charge 5₹ for the first 1.2KM and 7₹ for the subsequent 0.2KM? If BMTC charges, 5₹ for 1st stage. Then it should charge 5₹ + extra for next stage. But it shouldn't be more than 10₹.

You can just take 1 ticket(5₹) for 1st stage(1.2KM) and one more ticket(5₹) for the next stage(0.2KM). You can just travel 2 stages with 2 tickets for 10₹.

Turnsout BMTC is charging 3₹ extra on every ticket which covers atleast 2 stages. As lakhs of people travel in BMTC buses daily, in a month, this 3₹ turns into crores of rupees.

I am not sure when BMTC has started charging like this. A month back, I sent them an email asking for an explaination of unfair bus tickets and they haven't replied yet.

Update:

After sending this to BMTC officials, they have reduced 2nd stage bus fare by 2 Rs. Thanks to Gopala Kallapura, Krace Kumar & Thegesh GN for supporting the issue.

Why Blog Posts Are Better Than Scientific Papers?

Anand Reddy Pandikunta — Sun, 08 Jan 2017 17:03:38 GMT

Titus Brown wrote a blog post on why blog posts are better than scientific papers. Here are few more reasons for that.

Fast

Publishing blog posts is lightning fast(how fast can you type?). You can just publish it with a click after writing. However with scientific papers you have to wait months to get your work published.

Mutability

Blog posts are easy to edit. If you are using a version controlled system like git, any one can easily collaborate. You can also leave comments on (most) blog posts and can have discussion with the author and/or others. Scientific papers once published are hard to change.

No Gatekeepers

To publish blog posts, you can setup your own blog or use services like medium. There are no gatekeepers who says that you can't publish a blog post because they thinks its not worth it.

Organic

Blog posts tend to be casual and organic. You can crack a joke and readers will enjoy it. Scientific papers are formal. You spray some sarcasm and your paper never gets published.

What Is The Meaning Of Life?

Anand Reddy Pandikunta — Sun, 25 Dec 2016 18:29:23 GMT

The meaning of life is

the condition that distinguishes animals and plants from inorganic matter, including the capacity for growth, reproduction, functional activity, and continual change preceding death.

Source: Oxford Dictionary