BucketCTF 2023 - Clock 2
Table of Contents
BucketCTF 2023 - This article is part of a series.
Clock 2 #
Description #
One of my cybersecurity professors, Dr. Timely, randomly sent my this file and said if I can decode the message he will give me an A in the class. Can you help me out?
https://storage.ebucket.dev/clocks_hard.pcap
TL;DR #
Very similar to the previous challenge but the delta between the requests are now between 0.1 and 0.10 seconds.
My first attempt was to test decimal to ascii, which did not give anything conclusive. I then tried to define half of the values = 0 and another half = 1 to be even closer to the first challenge.
Solution #
With thsark I get the different deltas between the requests with a field.
I put them in cyberchef to keep only the number of seconds that I want to parse.
Then i replaced [0-4] with 0 and [5-9] with 1.
And finally I decode the binary in my recipe to get the flag.
Flag #
bucket{clocks_are_crazy_sometimes}