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Daily AlpacaHack

A daily CTF challenge with a fun new puzzle every day

What is Daily AlpacaHack?

We publish one simple, beginner-friendly or educational CTF challenge every day!

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Solve within 24 hours of release to appear on the leaderboard.

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Discussion with friends or AI is welcome (account sharing is prohibited).

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Today's Challenge

Submissions (latest 3)

SOLVED!

Jul 8, 4:03 PM

SOLVED!

Jul 8, 4:00 PM

SOLVED!

Jul 8, 3:44 PM

Leaderboard

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Try the first challenge

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

AlpacaHack 2100

Upcoming challenges reveal the , , and in advance.

Jul 2026

Solved

Unsolved

Upcoming

Mon

Tue

Wed

Thu

Fri

Sat

Sun

29

tchen

Web

Medium

70 solves

30

minaminao

Super Short System Exit

Misc

Medium

78 solves

1

admin

Misc

Welcome🌱

167 solves

2

hiikunz

Crypto

Easy🌱

112 solves

3

tchen

Web

Easy🌱

105 solves

4

hiikunz

Rev

Medium

90 solves

5

tchen

IP Blocked Secret

Web

Hard

55 solves

6

minaminao

duplicate entry

Misc

Easy🌱

105 solves

7

hiikunz

Crypto

Medium

86 solves

8

minaminao

Let's Poly1305!

Crypto

Medium

64 solves

9

shiragi

Misc

Easy🌱

21 solves

10

Planned topicSQL

Web

Medium

11

Planned topicStack

Pwn

Hard

12

Planned topicC++

Rev

Hard

13

Planned topicHTTP

Web

Easy🌱

14

Planned topicJail

Misc

Medium

15

Coming soon

16

Coming soon

17

Planned topicMAC

Crypto

Medium

18

Planned topicCGI

Web

Hard

19

Planned topicStack

Pwn

Hard

20

Coming soon

21

Coming soon

22

Planned topicCache

Web

Medium

23

Coming soon

24

Coming soon

25

Planned topicMAC

Crypto

Hard

26

Planned topicPython

Web

Hard

27

Coming soon

28

Coming soon

29

Coming soon

30

Coming soon

31

Coming soon

1

Planned topicWelcome

Misc

Welcome🌱

2

Coming soon

Want a harder challenge?

Writeups

Daily AlpacaHackに挑戦するつくよみちゃん07/08/Let's Poly1305!/minaminao

tsukuyomi-chan

ja

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ja

15 minutes ago

Writeup for Lazy RSA

baumroll1234

ja

18 hours ago

Writeup for Lazy RSA

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ja

18 hours ago

Writeup for Lazy RSA

goroshirow

ja

2026/07/07 15:23

Writeup for Style Your Alpaca

00xcanelo

ar

Style Your Alpaca

2026/07/07 12:55

Writeup for duplicate entry (by bash)

nitcelcius

ja

duplicate entry

2026/07/07 00:01

Writeup for duplicate entry

nirvana

ja

duplicate entry

2026/07/06 21:39

Writeup for duplicate entry

baumroll1234

ja

duplicate entry

2026/07/06 15:43

Writeup for Nano Services

tchen

author

en

2026/07/06 07:36

Rows:

private method

Topic: PythonReleased: Jul 9, 2026

21 solves

Easy🌱2.0

by

shiragi

The private method should not be callable...

private-method.tar.gz

description solves