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Daily AlpacaHack

A CTF challenge series with fun puzzles to enjoy every day

What is Daily AlpacaHack?

We regularly publish simple, beginner-friendly or educational CTF challenges!

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Today's Challenge
tan90909090tan90909090
integer division
Misc
Medium
43 solves
Submissions (latest 3)
kobutya

SOLVED!

Sep 14, 3:33 PM

nuhe

SOLVED!

Sep 14, 3:02 PM

pppp4649
pppp4649

SOLVED!

Sep 14, 2:58 PM

Leaderboard

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admin
AlpacaHack 2100
Misc
Welcome🌱
2,201 solves
Upcoming challenges reveal the , , and in advance.
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Sep 2026

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Want a harder challenge?

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Writeups

gattoartz

Writeup for Integer Writer

gattoartz

ja
Integer Writer

3 hours ago

Writeup for sin function vs. fsin instruction

lumma

ja
sin function vs. fsin instruction

4 hours ago

Writeup for ＼^o^／

lumma

ja
＼^o^／

2026/09/13 04:33

sp1n0z4

Writeup for Bitflip RSA

sp1n0z4

en
Bitflip RSA

2026/09/12 23:42

gattoartz

Writeup for Leaked Flag Checker

gattoartz

ja
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2026/09/07 13:39

gattoartz

Writeup for a fact of CTF

gattoartz

ja
a fact of CTF

2026/09/07 13:08

gattoartz

Writeup for AlpacaHack 2100

gattoartz

ja
AlpacaHack 2100

2026/09/07 13:07

Writeup for Vending Machine: Revised Version

baumroll1234

author
ja
Vending Machine: Revised Version

2026/09/06 15:02

nitcelcius

Writeup for Vending Machine: Revised Version (warn: some code reading ahead)

nitcelcius

ja
Vending Machine: Revised Version

2026/09/06 05:59

nitcelcius

Writeup for Let's Shut Down Linux (with reading)

nitcelcius

ja
Let's Shut Down Linux

2026/09/05 05:49

Rows:

integer division

Topic: Integer OverflowReleased: Sep 14, 2026

43 solves
Misc
Medium3.0

by

tan90909090

tan90909090

USER

SOLVED AT

kobutya

2 minutes ago

nuhe

34 minutes ago

pppp4649

pppp4649

37 minutes ago

reid

2 hours ago

akiramelon

3 hours ago

kapumoka

4 hours ago

xing

4 hours ago

tadanobutubutu

tadanobutubutu

5 hours ago

ctf-udon

ctf-udon

5 hours ago

curetwinkle

curetwinkle

7 hours ago

kuroiko

7 hours ago

dyktr06

7 hours ago

nashu

7 hours ago

kojikazu2005

8 hours ago

nomeaning

8 hours ago

thr246

8 hours ago

blackade

10 hours ago

mizore-fuyu

12 hours ago

a2zog

12 hours ago

togashi777

14 hours ago

tet3

14 hours ago

xnmhuveb

16 hours ago

sikoderu

16 hours ago

hiroyuki

16 hours ago

kakur41

kakur41

17 hours ago

Rows:

descriptionsolves