Entropy, a more scientific term for what we call “randomness” is the measure of uncertainty or disorder.
But the question is, how do we decide if something is random and more importantly, how much? Let’s find out!

Illusion of uncertainty

Is the direction of a ball bouncing off a wall is uncertain? No…


Let’s reverse Pixelize blur.

Note: GIMP is used as the photo editing tool in this tutorial.
There’s no way to retrieve 100% of the details from an image once it’s distorted.

In the previous article, we talked about how mathematical operations are used to apply filters to images and how…


Although I am not a professional source code auditor, I am a hyperactive programmer and security researcher. The article is based on my own experiences and reading various vulnerability reports throughout my journey in information security. Hence it might have some flaws that I would love to know about in…


Made with canva.com

Programming is an amazing skill to have and I believe it’s especially essential if you want to be good at information security. With the magic of programming, you can write exploits, automate things, get better understanding of how something works under the hood or find vulnerabilities going through source code.


This write-up assumes that the reader has intermediate (or higher) knowledge of regular expressions. If you are not very familiar with regular expressions, you might want to check out this tutorial. You may also want to read my introductory article about ReDOS.

I have been spending a good amount of…


A regular expression (or regex) is basically a search pattern. For example, the expression [cb]atwill match both cat and bat. This isn’t a regex tutorial so if you don’t know much about regex, go through this amazing cheat sheet before reading any further.

Let’s get started with some basics anyway…


During intelligence operations, we often come across images that may contain important information but they are too blurred, noisy or just unclear to make sense out of. In this article, I am going to talk about some techniques that we can use to retrieve information from blurred images.

How do filters work?

Every image…


tl;dr This article is about code golfing a PHP shell to 35 bytes while keeping it usable as well as secure. The web shell can be found on Github.

Ninjas need to be stealthy but trading off usability for stealth is a bit expensive. We want our web shell to…


This article is already kind of lengthy so let’s get straight to the point.

Every eAadhar letter is locked with a password which is a fixed string of following schema:

first_four_letters_of_name_in_uppercase + year_of_birth

Basically there are 4 uppercase alphabets & 4 digits involved. So how many combinations can be generated…

Somdev Sangwan

I make stuff, I break stuff and I make stuff that breaks stuff.

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