My CTF Challenges

Challenges I've made for public CTFs.

DownUnderCTF 2020

Fri, 18 Sept. 2020, 19:00 AEST — Sun, 20 Sept. 2020, 19:00 AEST

Website | CTFTime | Official Repository

Name	Category	Difficulty	Solves
rot-i	crypto	👶	447
babyrsa	crypto	⭐️	144
Extra Cool Block Chaining	crypto	⭐️⭐️	52
Hex Shift Cipher	crypto	⭐️⭐️	44
Cosmic Rays	crypto	⭐️⭐️	25
ImpECCable	crypto	⭐️⭐️⭐️	3
1337crypt	crypto	⭐️⭐️⭐️	3
LSB||MSB Calculation Game	crypto	⭐️⭐️⭐️	2

DownUnderCTF 2021

Fri, 24 Sept. 2021, 19:00 AEST — Sun, 26 Sept. 2021, 19:00 AEST

Website | CTFTime | Official Repository

Name	Category	Difficulty	Solves
no strings	reversing	👶	934
Substitution Cipher I	crypto	👶	362
Substitution Cipher II	crypto	⭐️	155
treasure	crypto	⭐️	102
flag loader	reversing	⭐️	85
write what where	pwn	⭐️	70
connect the dots	reversing	⭐️⭐️	47
ready, bounce, pwn!	pwn	⭐️⭐️	41
encrypted note	pwn	⭐️⭐️⭐️	22
flag checker	reversing	⭐️⭐️⭐️	16
gamer	reversing	⭐️⭐️	15
power sign	crypto	⭐️⭐️⭐️	14
yadlp	crypto	⭐️⭐️⭐️	14
flag printer	reversing	⭐️⭐️	8
bullet hell	reversing	⭐️⭐️	7
1337crypt v2	crypto	⭐️⭐️⭐️	3
Substitution Cipher III	crypto	⭐️⭐️⭐️	1

DownUnderCTF 2022

Fri, 23 Sept. 2022, 19:30 AEST — Sun, 25 Sept. 2022, 19:30 AEST

Website | CTFTime | Official Repository

Name	Category	Difficulty	Solves
babyp(y)wn	pwn	👶	643
source provided	rev	👶	365
baby arx	crypto	👶	279
js lock	rev	⭐️	136
login	pwn	⭐️	121
oracle for block cipher enthusiasts	crypto	⭐️	102
cheap ring theory	crypto	⭐️	101
rsa interval oracle i	crypto	⭐️	79
noteworthy	web	⭐️	60
ezpz-rev	rev	⭐️	42
rsa interval oracle ii	crypto	⭐️⭐️	36
ezpz-pwn	pwn	⭐️	33
xva	rev	⭐️⭐️	30
last digit	misc	⭐️	26
Crypto Casino	blockchain	⭐️	25
rsa interval oracle iii	crypto	⭐️⭐️	23
time locked	crypto	⭐️⭐️	18
click the flag	rev	⭐️⭐️	18
battlesweeper	misc	⭐️⭐️⭐️	18
kv_db	pwn	⭐️⭐️	17
faulty arx	crypto	⭐️⭐️⭐️	11
file magic	misc	⭐️⭐️	10
pac	pwn	⭐️⭐️	7
rsa interval oracle iv	crypto	⭐️⭐️⭐️	5
EVM Vault Mechanism	blockchain	⭐️⭐️⭐️	4
1337crypt v3	crypto	⭐️⭐️⭐️	2
kyber±	crypto	⭐️⭐️⭐️⭐️	1

DownUnderCTF 2023

Fri, 01 Sept. 2023, 19:30 AEST — Sun, 03 Sept. 2022, 19:30 AEST

Website | CTFTime | Official Repository

Name	Category	Difficulty	Solves
static file server	beginner	👶	594
downunderflow	beginner	👶	521
complementary	beginner	👶	436
randomly chosen	beginner	👶	365
flag art	beginner	👶	285
one byte	beginner	👶	189
confusing	beginner	👶	157
apbq rsa i	crypto	⭐️	126
masked squares flag checker	rev	⭐️	62
shifty mem	pwn	⭐️⭐️	40
mini dns server	misc	⭐️⭐️	39
sideways	rev	⭐️⭐️	29
fnv	crypto	⭐️⭐️	27
binary mail	pwn	⭐️⭐️	26
apbq rsa ii	crypto	⭐️⭐️	26
advanced vector expositions	rev	⭐️⭐️⭐️	12
lcg card gimmicks	crypto	⭐️⭐️	11
number theoretic flag checker	rev	⭐️⭐️	9
handshake	crypto	⭐️⭐️⭐️	4
encrypted mail	crypto	⭐️⭐️⭐️	3
dilithium±	crypto	⭐️⭐️⭐️⭐️	0

DownUnderCTF 2024

Fri, 05 July 2024, 19:30 AEST — Sun, 07 July 2024, 19:30 AEST

Website | CTFTime | Official Repository

Name	Category	Difficulty	Solves
number mashing	beginner	👶	299
vector overflow	beginner	👶	239
decrypt then eval	crypto	⭐️	197
yawa	beginner	👶	184
sign in	pwn	⭐️	95
jmp flag	rev	⭐️	71
pac shell	pwn	⭐️	55
pressing buttons	rev	⭐️⭐️	34
dungeon	rev	⭐️⭐️	22
sheep farm simulator	pwn	⭐️⭐️	21
average assembly assignment	rev	⭐️⭐️	13
pkijs<	misc	⭐️⭐️	7
Poly1305 OTM	crypto	⭐️⭐️	6
ESPecially secure boot	pwn	⭐️⭐️⭐️	3
adorable encrypted animal	rev	⭐️⭐️⭐️	3
pkijs=	misc	⭐️⭐️⭐️	1
kyber decryption oracle	crypto	⭐️⭐️⭐️⭐️	1

DownUnderCTF 2025

Fri, 18 July 2025, 19:30 AEST — Sun, 20 July 2024, 19:30 AEST

Website | CTFTime | Official Repository

Name	Category	Difficulty	Solves
SwiftPasswordManager: ClickMe	rev	⭐️	115
fakeobj.py	pwn	⭐️	106
yet another login	crypto	⭐️	44
SwiftPasswordManager: LoadMe	rev	⭐️⭐️	41
SwiftPasswordManager: CrackMe	rev	⭐️⭐️	21
rw.py	pwn	⭐️⭐️	15
SH-RSA	crypto	⭐️⭐️	13
certvalidated	crypto	⭐️⭐️⭐️	2

skateboarding dog CTF 2025

Fri, 26 September 2025, 10:00 AEST — Saturday, 27 September 2025, 15:00 AEST

Website | Official Repository

skateboarding dog CTF @ BSides Canberra 2025

Name	Category	Difficulty	Solves
Touch Grass	game	⭐️	217
supeRSAnic v1.0	crypto	⭐️	133
Long String of Flags	game	⭐️	107
Ruff-undable Goods	game, web	⭐️	48
dockjmp	pwn	⭐️	25
Okay Buddy	game, rev	⭐️⭐️	16
uppawcase	misc, pwn	⭐️⭐️	7
disc	crypto	⭐️⭐️	5
Lucky Visitor	pwn, ios	⭐️⭐️	3
LibEatPan	misc	⭐️⭐️	3
Uninvited Visitor	game, crypto	⭐️⭐️	3
supeRSAnic v2.0	crypto	⭐️⭐️	2
Pixelize as a Service	game, pwn	⭐️⭐️	1
encrypted file server	pwn, crypto	⭐️⭐️⭐️	0

Blue Water CTF 2024

Sun, 13 Oct. 2024, 01:00 AEDT — Mon, 14 Oct. 2024, 13:00 AEDT

Website | CTFTime

Name	Category	Difficulty	Solves
Kyber Noncense	crypto	⭐️⭐️	4

Cyber Apocalypse 2023

Sun, 19 March 2023, 00:00 AEDT — Thu, 23 March 2023, 23:59 AEDT

Website | CTFTime

HackTheBox approached me to develop these challenges, some details like the title and description for the challenges were created by them.

Name	Category	Difficulty	Solves
Colliding Heritage	crypto	⭐️	?
Biased Heritage	crypto	⭐️⭐️	?

Team Oceania Qualifiers 2024

Sat, 20 January 2024, 11:00 AEDT — Sat, 20 January 2024, 18:00 AEDT

Website

Name	Category	Difficulty	Solves
Echo Command Breaker	crypto	⭐️	17
Greeter	pwn	⭐️	9
Ruby Chef	web	⭐️⭐️⭐️	4
ESPer Flag Checker	rev	⭐️⭐️⭐️	3
Cryptography 101 Final Exam	crypto	⭐️⭐️	2
Additional Emoji Suffering	crypto	⭐️⭐️⭐️	2
Discrete Leaky PRNG	crypto	⭐️⭐️	1