Engineering & Code explores the full stack of modern tech—from bits and transistors to cloud fleets and formal proofs. Here you’ll find clear, rigorous walk-throughs of software design, embedded hardware, security architecture, and the physics that underpins them, always paired with code, schematics, and reasoning you can put to work.
Provenance is the ability to record the history of data and its place of origin. In general, it is the ability to determine the chronology of the ownership, custody or location of any object. The primary purpose of tracing the provenance of an object or entity is often to provide contextual and circumstantial evidence for […] read more
While I can’t get into the background here, I was recently asked to describe the most geeky event in history. Something like this is hard to bound and as I asked those around me I got lots of answers from moment the zero was invented (“without that, you got nothing”) to the first demo of […] read more
You can’t work long in computer science until you have to understand the halting problem. The halting problem is concerned with determining whether a program will finish running or continue to run forever. It has a storied history. In 1936, Alan Turing proved that a general algorithm to solve the halting problem for all possible […] read more
The latest fundamental computer security vulnerability, termed Shellshock, was discovered by a vulnerability researcher Stephane Chazelas (a linux shell expert living in the UK) which allows for arbitrary code execution on linux or mac computers through creating a custom environment variable. If you haven’t already, you need to patch your system(s) and you might be […] read more
During my time on the red team, we continually discussed the role of matched filters in everything from GPS to fire control radars. While I’m having a blast at DARPA where I work in cyber, I wanted to review an old topic and put MATLAB’s phased array toolbox to the test. (Yes, radar friends this […] read more
This was much harder than it should have been. While this is the certainly the most trivial post on crypto-math on the webs, I wanted to share my MATLAB xor code in the hope that I save someone else’s time. It is a basic property of cryptography that a one time pad must be used […] read more
We are swimming in a sea of information. Without encryption this whole operation would be a very public event. Encryption enables our communications to be anonymous or secure and makes e-commerce and private communications possible. Because of this, I registered for Dan Boneth’s cryptography course. At this point, I’ve only watched one lecture, but I […] read more
[mathjax] It has been awhile since I’ve studied optimization, but gradient descent is always good to brush up on. Most optimization involves derivatives. Often known as the method of steepest descent, gradient descent works by taking steps proportional to the negative of the gradient of the function at the current point. Mathematically, gradient descent is […] read more
During a recent CrossFit competition, flex on the mall, we had to accomplish a team chipper in which we were able to pick the order of team members in order to minimize our workout time. The workout was simple: 50 burpees, 40 over the box jumps, and 30 kettle-bell snatches. Each exercise had to be […] read more
[mathjax] Well, I certainly forget things faster than I learn them. Today is a quick review of Bessel functions and their applications to signal processing. The Bessel functions appear in lots of situations (think wave propagation and static potentials), particularly those that involve cylindrical symmetry. While special types of what would later be known as […] read more