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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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Today's Challenge

A slight mistake

Submissions (latest 3)

SOLVED!

Jul 10, 4:40 PM

SOLVED!

Jul 10, 4:16 PM

SOLVED!

Jul 10, 4:15 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

78 solves

30

minaminao

Super Short System Exit

Misc

Medium

79 solves

1

admin

Misc

Welcome🌱

175 solves

2

hiikunz

Crypto

Easy🌱

114 solves

3

tchen

Web

Easy🌱

107 solves

4

hiikunz

Rev

Medium

94 solves

5

tchen

IP Blocked Secret

Web

Hard

58 solves

6

minaminao

duplicate entry

Misc

Easy🌱

111 solves

7

hiikunz

Crypto

Medium

93 solves

8

minaminao

Let's Poly1305!

Crypto

Medium

71 solves

9

shiragi

Misc

Easy🌱

100 solves

10

hiikunz

Web

Medium

64 solves

11

baumroll1234

A slight mistake

Pwn

Hard

10 solves

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

Writeup for Let's Poly1305!

kurimochi

ja

Let's Poly1305!

4 hours ago

Writeup for private method

nitcelcius

ja

7 hours ago

Writeup for Find XOR key

haruhana

ja

14 hours ago

Writeup for private method

nirvana

ja

18 hours ago

Writeup for private method

baumroll1234

ja

2026/07/09 16:53

Writeup for Let's Poly1305!

baumroll1234

ja

Let's Poly1305!

2026/07/08 20:20

Writeup for Let's Poly1305!

goroshirow

ja

Let's Poly1305!

2026/07/08 17:07

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

tsukuyomi-chan

ja

Let's Poly1305!

2026/07/08 15:59

Daily AlpacaHackに挑戦するつくよみちゃん07/07/Lazy RSA/hiikunz

tsukuyomi-chan

ja

2026/07/08 15:59

Writeup for Lazy RSA

baumroll1234

ja

2026/07/07 21:50

Rows:

A slight mistake

Topic: StackReleased: Jul 11, 2026

10 solves

Hard7.5

by

baumroll1234

USER	SOLVED AT
mak0tan	51 minutes ago
kannrisha	1 hour ago
hiikunz	1 hour ago
kurgm	1 hour ago
pppp4649	1 hour ago
cat22222	1 hour ago
tadanobutubutu	2 hours ago
rsk0315	2 hours ago
syn9	2 hours ago
umineko	2 hours ago

Rows:

description solves