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Tag: Flag Checker

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Flag Checker

Related:
#Obfuscation
#Anti Decompiler
#AArch64
#Bitwise Operation
#Hash Function
#Optimization
#x86-64

Flag checkers are a common type of challenge in the Reverse Engineering category.

An executable or script called a flag checker takes the player's input and outputs whether that input matches the flag.

These challenges may also be called "crackmes" in a broader sense. (automatically translated from Japanese)

minaminao
·Updated May 3, 2026
Flag Checker Challenges
Leaked Flag Checker
minaminao

minaminao

Rev
606 solves
Ruby Flag Checker
hiikunz

hiikunz

Rev
301 solves
read-a-binary
tan90909090

tan90909090

Rev
239 solves
Sugoi Flag Checker
chocorusk

chocorusk

Rev
216 solves
masking tape
arata-nvm

arata-nvm

Rev
177 solves
README.pdf
arata-nvm

arata-nvm

Rev
152 solves
Simple Flag Checker
keymoon

keymoon

Rev
129 solves
Optimized expression
tan90909090

tan90909090

Rev
120 solves
BINARY IN THE FUTURE.
yu212

yu212

Rev
71 solves
hidden
arata-nvm

arata-nvm

Rev
71 solves
decompile me
ptr-yudai

ptr-yudai

Rev
48 solves
Jerry's flag checker
soon-haari

soon-haari

Crypto
34 solves
vcipher

sugi

Rev
30 solves
pytecode
xornet

xornet

Rev
26 solves
mimikyu
ptr-yudai

ptr-yudai

Rev
16 solves
subway
arata-nvm

arata-nvm

Rev
16 solves
I2C Device
ptr-yudai

ptr-yudai

Rev
10 solves
fvm
ptr-yudai

ptr-yudai

Rev
8 solves
imgchk
ptr-yudai

ptr-yudai

Rev
8 solves
Jump
n01e0

n01e0

Rev
7 solves
topology
ptr-yudai

ptr-yudai

Rev
6 solves
Chirashi-sushi
keymoon

keymoon

Rev
2 solves
Jump-bugfix
n01e0

n01e0

Rev
1 solves
q-solved
ptr-yudai

ptr-yudai

Quantum
Rev
1 solves

Leaked Flag Checker

Daily AlpacaHackTopic: C, Flag CheckerReleased: Dec 4, 2025

606 solves
Rev

by

minaminao

minaminao

Writeups

minaminao

Writeup for Leaked Flag Checker

minaminao

author
ja

5 months ago


chjwoo

Writeup for Leaked Flag Checker

en

5 months ago


trimscash

Daily AlpacaHack 1週間目Writeup 12/01~12/07

ja

4 months ago


toratako

[SPOILER] Daily AlpacaHack Writeup for 12-01 to 12-14

ja

4 months ago



mimumi

Writeup for Leaked Flag Checker

ja

4 months ago





shun2439

Writeup for Leaked Flag Checker

ja

3 months ago


descriptionsolveswriteups