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!

Join Anytime

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

Not a Competition

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

Solution Sharing Rules

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

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Today's Challenge

Submissions (latest 3)

roaris

SOLVED!

Jul 27, 6:15 PM

goat-antony2008

SOLVED!

Jul 27, 5:29 PM

rsk0315

SOLVED!

Jul 27, 5:11 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.

Upcoming challenges reveal the , , and in advance.

Jul 2026

Solved

Unsolved

Upcoming

Mon

Tue

Wed

Thu

Fri

Sat

Sun

tchen

Nano Services

Web

Medium

88 solves

minaminao

Super Short System Exit

Misc

Medium

84 solves

admin

Alpaca Nation

Misc

Welcome🌱

254 solves

hiikunz

Flag is A+B

Crypto

Easy🌱

154 solves

tchen

Lucky Redirect

Web

Easy🌱

148 solves

hiikunz

Renda

Rev

Medium

113 solves

tchen

IP Blocked Secret

Web

Hard

67 solves

minaminao

duplicate entry

Misc

Easy🌱

146 solves

hiikunz

Lazy RSA

Crypto

Medium

105 solves

minaminao

Let's Poly1305!

Crypto

Medium

76 solves

shiragi

private method

Misc

Easy🌱

142 solves

hiikunz

secret-table-3

Web

Medium

86 solves

baumroll1234

A slight mistake

Pwn

Hard

71 solves

tan90909090

Compile time flag checker

Rev

Hard

56 solves

baumroll1234

Redirecting to Login Page

Web

Easy🌱

158 solves

tchen

You've Got Shlex

Misc

Medium

88 solves

minaminao

Let's Poly1305! 2

Crypto

Hard

64 solves

tchen

Beat the Alpaca Lord

Web

Medium

91 solves

pppp4649

biribiri

Crypto

Medium

86 solves

tchen

Greetings CGI

Web

Hard

71 solves

hiikunz

no win func

Pwn

Hard

74 solves

tchen

Alpaca Blog

Web

Easy🌱

118 solves

tan90909090

NOP Variant

Rev

Misc

Medium

65 solves

ark

jinjail

Misc

Hard

43 solves

tchen

True or False

Misc

Medium

70 solves

minaminao

Cache Me If You Can 2

Web

Hard

52 solves

k0080

what-is-my-pointer

Pwn

Hard

47 solves

tchen

Greetings i18n

Web

Hard

48 solves

tchen

RFC100008

Web

Easy🌱

82 solves

2501

One More Approval

Crypto

Medium

18 solves

2501

Planned topicZIP

Misc

Medium

Coming soon

admin

Planned topicWelcome

Misc

Welcome🌱

Coming soon

Want a harder challenge?

Go to B-SIDE

Writeups

Writeup for Leaked Flag Checker

haruhana

Leaked Flag Checker

15 hours ago

Writeup for no win func

nirvana

no win func

2026/07/26 12:18

Writeup for what-is-my-pointer

nirvana

what-is-my-pointer

2026/07/26 00:24

Writeup for Cache Me If You Can 2 (with PowerShell)

nitcelcius

Cache Me If You Can 2

2026/07/25 14:14

Writeup for True or False

baumroll1234

True or False

2026/07/23 20:57

Writeup for True or False

nirvana

True or False

2026/07/23 15:05

Writeup for jinjail

goroshirow

jinjail

2026/07/23 07:16

Writeup for NOP Variant

umineko

NOP Variant

2026/07/22 04:11

Daily AlpacaHackに挑戦するつくよみちゃん07/21/NOP Variant/tan90909090

tsukuyomi-chan

NOP Variant

2026/07/21 16:33

Writeup for Alpaca Blog

nirvana

Alpaca Blog

2026/07/21 13:38

Rows:

Elliptic Equation

Topic: Elliptic CurveReleased: Jun 13, 2026

63 solves

Crypto

Hard5.5

pppp4649

USER	SOLVED AT
tmatsuura	2026/07/06 11:49
nakamulab	2026/06/29 12:52
kuroiko	2026/06/27 13:28
tsukuyomi-chan	2026/06/27 07:05
y8w3ly	2026/06/23 13:56
stepbystepbymyself	2026/06/21 13:19
pineapple	2026/06/18 17:55
shoki	2026/06/17 04:15
sp1n0z4	2026/06/16 16:21
zayncancook	2026/06/16 14:20
hiroyuki	2026/06/15 01:46
redpo	2026/06/14 13:57
tyage	2026/06/14 13:08
serioton	2026/06/14 00:15
tomatonosenpai	2026/06/13 14:57
goroshirow	2026/06/13 14:35
tenagazaru	2026/06/13 14:24
nomeaning	2026/06/13 13:47
kowerkoint	2026/06/13 13:14
tsuji1	2026/06/13 12:44
kakur41	2026/06/13 12:26
ahnmo	2026/06/13 11:57
kitatai	2026/06/13 10:54
syn9	2026/06/13 10:39
labpump	2026/06/13 09:33