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

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No solved challenges yet.

Today's Challenge

Submissions (latest 3)

yoshy

SOLVED!

Jun 23, 10:45 PM

rsk0315

SOLVED!

Jun 23, 10:37 PM

baumroll1234

SOLVED!

Jun 23, 9:36 PM

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🌱

236 solves

minaminao

Cache Me If You Can

Web

Easy🌱

198 solves

minaminao

vm1

Misc

Medium

94 solves

pppp4649

Small e

Crypto

Easy🌱

134 solves

minaminao

RPS GAME

Misc

Crypto

Medium

96 solves

nozokare

Flag for localhost

Web

Easy🌱

156 solves

tan90909090

C++ flag checker

Rev

Hard

84 solves

shiragi

Guess IP

Misc

Easy🌱

140 solves

nozokare

A Piece of DHKE

Crypto

Medium

81 solves

shiragi

chmod-swapper

Misc

Medium

84 solves

tchen

Alpaca Certification

Web

Easy🌱

154 solves

rsk0315

Floating Equality

Misc

Medium

89 solves

pppp4649

Elliptic Equation

Crypto

Hard

59 solves

tchen

CAuth

Web

Hard

65 solves

minaminao

SITE/2

Web

Easy🌱

117 solves

tan90909090

Xored PNG

Misc

Medium

84 solves

tchen

Looks like Alpacahack

Web

Medium

80 solves

shiragi

Catrunner 2

Misc

Easy🌱

103 solves

minaminao

Flag Printer 20XX

Misc

Medium

61 solves

nozokare

xorshift521

Crypto

Hard

54 solves

k0080

what-is-my-size

Pwn

Hard

63 solves

minaminao

✌️✌️✌️

Crypto

Easy🌱

83 solves

tchen

Secret Renderer

Web

Medium

65 solves

kanon

honk the klaxon

Crypto

Medium

23 solves

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🌱

hiikunz

Planned topicMathematics

Crypto

Easy🌱

Coming soon

Want a harder challenge?

Go to B-SIDE

Writeups

Daily AlpacaHackに挑戦するつくよみちゃん 06/23/Secret Renderer/tchen

tsukuyomi-chan

Secret Renderer

6 hours ago

Writeup for ✌️✌️✌️

baumroll1234

✌️✌️✌️

2026/06/22 18:13

Writeup for ✌️✌️✌️

minaminao

author

✌️✌️✌️

2026/06/22 17:14

Daily AlpacaHackに挑戦するつくよみちゃん 06/22/✌️✌️✌️/minaminao

tsukuyomi-chan

✌️✌️✌️

2026/06/22 16:47

Writeup for ✌️✌️✌️

tadanobutubutu

✌️✌️✌️

2026/06/22 15:53

Writeup for what-is-my-size

tadanobutubutu

what-is-my-size

2026/06/22 13:57

Writeup for what-is-my-size

goroshirow

what-is-my-size

2026/06/21 16:19

Writeup for xorshift521

umineko

xorshift521

2026/06/21 04:52

Daily AlpacaHackに挑戦するつくよみちゃん 06/20/xorshift521/nozokare

tsukuyomi-chan

xorshift521

2026/06/20 15:40

Writeup for xorshift521

baumroll1234

xorshift521

2026/06/20 15:22

Rows:

Small N

Topic: RSAReleased: May 3, 2026

179 solves

Crypto

Easy🌱3.5

pppp4649