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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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Sharing solutions is allowed only after 24 hours have passed since release.

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Today's Challenge

Submissions (latest 3)

SOLVED!

Jul 9, 4:25 PM

SOLVED!

Jul 9, 4:19 PM

SOLVED!

Jul 9, 4:05 PM

Leaderboard

Period

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

76 solves

30

minaminao

Super Short System Exit

Misc

Medium

78 solves

1

admin

Misc

Welcome🌱

170 solves

2

hiikunz

Crypto

Easy🌱

113 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🌱

110 solves

7

hiikunz

Crypto

Medium

92 solves

8

minaminao

Let's Poly1305!

Crypto

Medium

71 solves

9

shiragi

Misc

Easy🌱

95 solves

10

hiikunz

Web

Medium

16 solves

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

Writeup for Let's Poly1305!

baumroll1234

ja

Let's Poly1305!

20 hours ago

Writeup for Let's Poly1305!

goroshirow

ja

Let's Poly1305!

23 hours ago

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

Writeup for Lazy RSA

nirvana

ja

2026/07/07 21:37

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

Rows:

super-tomato

Topic: Number TheoryReleased: Jan 2, 2026

436 solves

Easy🌱3.0

by

kanon

Tags

USER	SOLVED AT
hulgas	2026/07/08 08:01
ibrahim	2026/07/07 06:16
paper	2026/07/06 00:42
kenlatte	2026/07/01 11:10
reid	2026/06/30 13:23
sasamari-myun	2026/06/27 09:56
garangara	2026/06/27 09:50
ririnbaru	2026/06/26 05:28
tmatsuura	2026/06/25 04:53
charo	2026/06/19 11:26
kaitani	2026/06/17 05:02
hikaru	2026/06/08 13:47
tadanobutubutu	2026/06/07 16:59
qwra	2026/06/04 03:38
oshiruko-umauma	2026/05/30 02:13
toto1010orange	2026/05/27 11:31
nakamulab	2026/05/26 12:29
sig-255	2026/05/25 01:15
soranjiro	2026/05/24 08:39
rito	2026/05/23 18:49
akuro169	2026/05/23 04:50
novice1248	2026/05/21 13:13
redpo	2026/05/21 06:26
hori	2026/05/20 04:37
nanashiku	2026/05/19 06:18

Rows:

description solves writeups