Julekalender 2021 - Luke 1

28 Nov 2021 av Joakim Algrøy

Trenger du et avbrekk fra eksamenslesing? Helt Sikker vil de neste fire søndagene publisere en liten CTF-oppgave. Alle som løser oppgaven er hver uke med i trekningen av et foodora-gavekort! Det blir en ekstra trekning på slutten blant de som løser alle fire :)

Her er første luke:

Santa’s Spy

Norwegian counter-intelligence suspects that Santa’s elves have been illegally spying on Norwegian citizens. An elf has been observed taking pictures of people from afar, breaking into a home, and sending radio transmissions from the woods. A radio transmission was picked up by counter-intelligence, and they suspect the elf was reporting something back to the North Pole, but it’s not clear what was reported as we only hear a fast and high-pitched chirping noise. Can you please help figure out what the elf transmitted back to base?

Attached you’ll find the evidence file for the arrested elf, including the items confiscated as well as the radio transmission: investigation.zip

Please submit your answer here.

Hints:

• A basic audio editor might be useful. I like Audacity.
• We’ve heard rumors that Santa uses an encryption method so strong it is information-theoretically secure.