These are my solutions to the 2026 ICOA Practice Challenges. I still have a long way to go write the solutions, where the written ones will be marked by 🟩, and 🟪 indicates there's a problem to the challenge or as a partial solve. Any questions or suggestions and be disscused in the Discussion Page.

Notice:

There have been some questions that were removed, and the files of some challenges are also missing for some reason

Write-Ups

Crypto

Task	Points
🟩 RSA101	178
🟩 Multi-layer	340
🟩 Incorrect Implementation of RSA	372
🟩 Mysteries of the Tomb	384
🟪 Wise Words	428
🟩 Sheet Music Cipher	444
🟩 That's Not My Unicode	460
The Perfect Breakfast	472
#InMyLibraryClashingEra	484

Steg

Task	Points
🟩 Cheese	192
🟩 Dogs Always Know	408
🟩 Looking through the sound	412
🟩 In the words of Taylor	436
🟩 TLSB	444
🟩 Nothing to See Here	456
🟩 In the fine print	476
🟩 Stuck in Your Head	480
Layer Cake	496

Forensics

Task	Points
🟩 HexedHeaders	416
🟩 Keylogger	436
🟩 Ping	436
🟩 obfuscated script	456
🟩 There is always a trace	468
🟩 Sound Inversion	472

Rev

Task	Points
🟩 Too Many Flags	432
Xanarto	480
cafe1995	492
Doors 3	496
Doors 2	496
Doors	496

OSINT

Task	Points
Go git the door	444
Online Presence	460

Pwn

Task	Points
Echo Chamber	492
Flag Fish	500
fridge	500
Say Shells!	500
Show Me What You GOT!	500

Removed (Most of them are MISC and OSINT, which I have not taken my time to compelte hence a lot is missing)

Task	Points
🟩 The Job Interview	464

Overview

The 2026 Sydney International Cybersecurity Events have been officially upgraded to ICOA — the International Cyber Olympiad in AI — the World's First AI Security Olympiad. ICOA is a fully independent programme focused on AI security, with 30+ nations and regions accredited. Our dual-track format: Day 1 AI4CTF + Day 2 CTF4AI.

Good luck. We hope you enjoy the challenge!