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.

Solve stats

/19

No solved challenges yet.

Today's Challenge

Submissions (latest 3)

reid

SOLVED!

Jun 19, 10:27 AM

cat22222

SOLVED!

Jun 19, 9:59 AM

trimscash

SOLVED!

Jun 19, 9:03 AM

Leaderboard

Period

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.

Jun 2026

Solved

Unsolved

Upcoming

Mon

Tue

Wed

Thu

Fri

Sat

Sun

admin

Half-Year Recap

Misc

Welcome🌱

222 solves

minaminao

Cache Me If You Can

Web

Easy🌱

186 solves

minaminao

vm1

Misc

Medium

92 solves

pppp4649

Small e

Crypto

Easy🌱

128 solves

minaminao

RPS GAME

Misc

Crypto

Medium

95 solves

nozokare

Flag for localhost

Web

Easy🌱

147 solves

tan90909090

C++ flag checker

Rev

Hard

81 solves

shiragi

Guess IP

Misc

Easy🌱

133 solves

nozokare

A Piece of DHKE

Crypto

Medium

80 solves

shiragi

chmod-swapper

Misc

Medium

80 solves

tchen

Alpaca Certification

Web

Easy🌱

146 solves

rsk0315

Floating Equality

Misc

Medium

89 solves

pppp4649

Elliptic Equation

Crypto

Hard

57 solves

tchen

CAuth

Web

Hard

61 solves

minaminao

SITE/2

Web

Easy🌱

110 solves

tan90909090

Xored PNG

Misc

Medium

83 solves

tchen

Looks like Alpacahack

Web

Medium

74 solves

shiragi

Catrunner 2

Misc

Easy🌱

89 solves

minaminao

Flag Printer 20XX

Misc

Medium

45 solves

nozokare

Planned topicRNG

Crypto

Hard

k0080

Planned topicHeap

Pwn

Hard

minaminao

Planned topicSecret Sharing

Crypto

Easy🌱

tchen

Planned topicNginx

Web

Medium

Coming soon

colza

Planned topicArchive

Misc

Easy🌱

Coming soon

bubu

Planned topicClient-Side

Web

Hard

pppp4649

Planned topicTBA

Pwn

Hard

Coming soon

admin

Planned topicWelcome

Misc

Welcome🌱

Coming soon

Want a harder challenge?

Go to B-SIDE

Writeups

Writeup for Catrunner 2

nirvana

Catrunner 2

1 hour ago

Daily AlpacaHackに挑戦するつくよみちゃん 06/18/Catrunner 2/shiragi

tsukuyomi-chan

Catrunner 2

19 hours ago

Writeup for Looks like Alpacahack

nirvana

Looks like Alpacahack

2026/06/18 00:44

Daily AlpacaHackに挑戦するつくよみちゃん 06/17/Looks like Alpacahack/tchen

tsukuyomi-chan

Looks like Alpacahack

2026/06/17 17:12

Writeup for Looks like Alpacahack

baumroll1234

Looks like Alpacahack

2026/06/17 16:10

Writeup for Looks like Alpacahack

goroshirow

Looks like Alpacahack

2026/06/17 15:07

Writeup for Xored PNG

baumroll1234

Xored PNG

2026/06/16 20:22

Writeup for Xored PNG

tadanobutubutu

Xored PNG

2026/06/16 17:17

Daily AlpacaHackに挑戦するつくよみちゃん 06/16/Xored PNG/tan90909090

tsukuyomi-chan

Xored PNG

2026/06/16 17:06

Writeup for SITE/2

tadanobutubutu

SITE/2

2026/06/16 10:33

Rows:

Stateless Auth

Topic: JWTReleased: Jan 25, 2026

180 solves

Web

Medium

tchen

USER	SOLVED AT
umachaba	2026/06/11 15:49
toto1010orange	2026/06/04 14:04
rito	2026/05/29 15:01
nakamulab	2026/05/28 01:52
sasarafu	2026/05/27 17:11
miraicantsleep	2026/05/25 02:36
muhammed	2026/05/06 10:35
baloon	2026/05/04 14:45
claustra01	2026/04/29 14:17
erasedtree169	2026/04/18 00:24
honburi	2026/04/16 00:19
four0four	2026/04/14 12:31
thayato	2026/04/09 13:15
ito	2026/04/07 15:43
kanon	2026/04/01 02:53
over20	2026/03/28 17:45
junda	2026/03/25 12:10
kurenaif	2026/03/22 15:06
stepbystepbymyself	2026/03/21 14:32
popopo	2026/03/15 09:49
flugel	2026/03/13 16:17
kapumoka	2026/03/09 18:48
seaza	2026/03/09 12:47
koufu193	2026/03/07 09:15
htbru	2026/03/06 13:57