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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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Solve each challenge within its time window to appear on the leaderboard.

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Today's Challenge
pppp4649pppp4649
Σecret
Crypto
Easy🌱
36 solves
Submissions (latest 3)
roaris

SOLVED!

Oct 24, 10:48 AM

shiragi

SOLVED!

Oct 24, 10:34 AM

Leaderboard

Try the first challenge

Is this your first CTF? Let's begin by tackling the first challenge released on Daily AlpacaHack.

View challenge
admin
AlpacaHack 2100
Misc
Welcome🌱
2,301 solves
Upcoming challenges reveal the , , and in advance.
Prev

Oct 2026

Next
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k0080k0080
what is my pointer 2
Pwn
Hard
47 solves
1
admin
Baby Alpaca
Misc
Welcome🌱
154 solves
2
tan90909090tan90909090
C# File-based app
Rev
Easy🌱
76 solves
3-4
2501
Shared Prime
Crypto
Medium
87 solves
5-8
tan90909090tan90909090
fsbase modification
Pwn
Hard
59 solves
9-12
2501
Almost Shared Prime
Crypto
Hard
44 solves
 
2501
Almost Shared Prime
Crypto
Hard
44 solves
13-14
tan90909090tan90909090
cowsay jail
Misc
Medium
60 solves
15-18
hiikunzhiikunz
decreasing
Misc
Hard
34 solves
19-22
tan90909090tan90909090
x32 ABI flag checker
Rev
Hard
31 solves
23-24
pppp4649pppp4649
Σecret
Crypto
Easy🌱
36 solves
25-28
k0080k0080
Planned topicmalloc
Pwn
Hard
 
Planned topicmalloc
Pwn
Hard
29
Coming soon
30
Coming soon
31
Coming soon
1
Coming soon

Want a harder challenge?

Go to B-SIDE

Writeups

tadanobutubutu

Writeup for x32 ABI flag checker

tadanobutubutu

ja
x32 ABI flag checker

23 hours ago

ojun

Writeup for fsbase modification

ja

2026/10/15 13:59

tadanobutubutu

Writeup for cowsay jail

ja

2026/10/15 08:42

tadanobutubutu

Writeup for Almost Shared Prime

Rows:

Small e

Topic: RSAReleased: Jun 4, 2026

194 solves
Crypto
Easy🌱3.5

by

pppp4649

pppp4649

Writeups

Writeup for Small e

goroshirow

ja

2026/06/04 15:09



nirvana

Writeup for Small e

ja

2026/06/05 07:50



Daily AlpacaHackに挑戦するつくよみちゃん 06/04/Small e/pppp4649, 06/05/RPS GAME/minaminao

ja

2026/06/07 08:50



kakur41

Writeup for Daily AlpacaHack 5/31-6/6

ja

2026/06/28 11:59


nitcelcius

with Sagemath

ja

2026/06/04 15:32


tadanobutubutu

Writeup for Small e

ja

2026/06/05 08:56

descriptionsolveswriteups