I’ve (re)started the Cryptopals Crypto Challenges too many times to remember. I think I’ve implemented a Vigenère solution from scratch enough times, and I need a new technical challenge that I can periodically jump into with enthusiasm and then procrastinate into memory oblivion.

Enter, Hack The Box.

The first challenge is to get an invite code to create an account.


***** Spoilers Ahead *****

On the invite page, we’re presented with a simple form that prompts for an invite code. I started by trying the simplest stuff first:

  1. Just hitting the Sign Up button.
  2. Typing some random garbage into the field.

Neither of these…

Some Preparatory Musings

I recently got an invitation to watch a debate between the UMBC philosophy and computer science departments regarding the ethics of brain-computer interfaces.

BCIs are those interfaces that seek to bypass human motor and sensory systems through direct connectivity to the central nervous system. The field is nascent, but it’s absolutely technologically feasible, and sci-fi fans the world over could probably enumerate the milestones leading to a dystopian future of human-powered machines and malevolent AIs. I’m generally more optimistic and endlessly intrigued by the philosophical questions such technology raises.

My thoughts on the subject are roughly summarized by the following…

And Other Fun with Cryptography

I’ve been messing around with some basic cryptography challenges ever since DEFCON, which was a ton of fun and very informative. The most recent challenge involved breaking a Vigenere cipher (also known as a repeating key XOR).

Here’s the basic algorithm:

1. Calculate normalized Hamming distances for various key sizes, and take the smallest one.
2. Chunk cipher text into key-sized chunks.
3. Transpose the chunk bytes.
4. Find the single-byte XOR key for each transposed chunk with frequency analysis.
5. Concatenate the keys, and find your plain text.
6. ???
7. Profit!

Fun stuff! So satisfying to see the plain text at the end of a challenge.

Reflections on an Influential Perspective

In nearly every one of my graduate reading seminars, at some point, we were asked to read Professor Elke Duncker’s 2002 Joint Conference on Digital Libraries (JCDL) presentation, “Cross-cultural usability of the library metaphor”. It’s an excellent academic work that my professors typically used to kick-off discussions on “quick-and-dirty” ethnography in HCI research, and value-centric design.

I’ve actually made it a point to read the paper several times outside of class because of how compelling I find some of the ideas it presents. …

Pseudonyms I’ve Adopted for the Monograms

  • Ulav Grado Hildabrand
  • Alessandro Horatio Hernez
  • Mortimer Marlin Mendelbaum
  • Artemis Hogarth Arkham
  • Hannibal Ungar Harmon
  • Geoffrey Ren-Ronson
  • Amir Ram Ghafir
  • Eugene Evigo Kerchiev
  • Hector Mansoor Mahound
  • Lawrence Oliver Lailabert
  • Quinn Elliot Dresdahl
  • Aloysius Wayne Wilburton

A Quick Chemical Calculation

I weigh about 155 lbs. If you convert that to metric units, it’s about 70,306 grams, which is about as many paperclips.

The average human body is mostly water, about 80-some percent. There’s other stuff in there too, though. In fact, the rough breakdown by weight is about 65% Oxygen, 18% Carbon, 10% Hydrogen, 3% Nitrogen, 1.5% Calcium and 1.2% Phosphorus. There’s a bunch of smaller amounts of other stuff in there too.

Using those numbers, you find that the I have about 45,699 grams of Oxygen in me, 12,655 grams of Carbon, 7,030 grams of Hydrogen, 2,109 grams of…

Karim Said


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