I was teamed-up with @blackb6a on Google CTF this time. I have solved 7 challenges alone and 3 challenges with my teammates.

In particular, Oracle is a crypto challenge with 13 solves. It has got me spending 12 hours. All in all, it was a great experience in terms of learning, but my liver hurts. This piece of writeup may be very computation intensive, just because I would like to make everything clear.

nookcrypt is a netcat service that have no source code released. There are two functions exposed:

1. Gets an encrypted copy of the flag (and the message hello world).
2. Encrypts an arbitrary message.

I was teamed up with @shellphish this time for De1CTF. During the game, I have solved 5 (out of 7) cryptography challenges individually, and a reverse challenge and a misc challenge in cooperation with DuSu and fs0c.

I said that I’ll commit the solution scripts to my Github after I have managed to prettify them. It never happened. I will not make the same promise again.

A Plaid Puzzle is a RPG game written in PuzzleScript. In the game, you are able to control as the player and you could move around and mess with a string. The game is available online on PuzzleScript.net.

It has been a very long time that I’ve compiled a writeup. This time I have played on my own as @blackb6a. Let me write on some particular interesting ideas that I have learnt in the challenges. Bear with me if you find this writeup too math-intensive.

The solution scripts will be committed to my Github repository sooner or later, after I’ve managed to prettify them.