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)

cocoa

SOLVED!

May 9, 4:21 PM

kurgm

SOLVED!

May 9, 4:18 PM

toomer

SOLVED!

May 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.

Upcoming challenges reveal the , , and in advance.

Jan 2026

Solved

Unsolved

Upcoming

Mon

Tue

Wed

Thu

Fri

Sat

Sun

kanon

one-p-rsa

Crypto

Easy

247 solves

soon-haari

RBG

Crypto

Very Hard

126 solves

admin

108

Misc

Easy

306 solves

admin

Happy New Year

Misc

Welcome

583 solves

kanon

super-tomato

Crypto

Easy

406 solves

hiikunz

Ruby Flag Checker

Rev

Easy

301 solves

minaminao

Fushigi Crawler

Web

Easy

367 solves

kurenaif

Encoding Basics

Crypto

Misc

Easy

330 solves

minaminao

jailiaj

Misc

Easy

291 solves

hiikunz

Square RSA

Crypto

Medium

245 solves

ark

secret-table

Web

Medium

281 solves

hiikunz

SwapSwap

Misc

Easy

301 solves

theoremoon

RSA2026

Crypto

Medium

219 solves

keymoon

crazython

Rev

Medium

198 solves

hiikunz

Basic Buffer Overflow

Pwn

Medium

192 solves

tchen

I wanna be the Admin

Web

Easy

296 solves

ark

free-comment

Misc

Hard

154 solves

hiikunz

Five Alpacas

Crypto

Easy

204 solves

k0080

Short Writer

Pwn

Hard

129 solves

minaminao

Base Length

Misc

Medium

159 solves

hiikunz

dice roll

Web

Medium

207 solves

chocorusk

ChaChaCha

Crypto

Medium

164 solves

k0080

system-v

Rev

Hard

121 solves

ark

dockerstack

Misc

Easy

184 solves

hiikunz

Animal Viewer

Web

Medium

161 solves

minaminao

Bashrunner

Misc

Hard

124 solves

yu212

Paca Paca Authenticator

Crypto

Medium

136 solves

tchen

Stateless Auth

Web

Medium

174 solves

keymoon

git gc

Misc

Medium

160 solves

chocorusk

ToyPQC

Crypto

Hard

112 solves

tchen

No JS

Web

Medium

138 solves

k0080

shellcode-101

Pwn

Medium

143 solves

yu212

Linear Coffee Generator

Crypto

Hard

118 solves

ark

optimal-sort

Misc

Hard

107 solves

admin

Camelidae

Misc

Welcome

404 solves

Want a harder challenge?

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Writeups

Writeup for reused n baumroll1234 ja reused n 29 minutes ago
Writeup for Daily AlpacaHack 5/3-5/9 kakur41 ja reused n +6 1 hour ago
Writeup for reused n goroshirow ja reused n 1 hour ago
Writeup for Vending Machine baumroll1234 author ja Vending Machine 3 hours ago
Writeup for Vending Machine tadanobutubutu ja Vending Machine 6 hours ago
Daily AlpacaHackに挑戦するつくよみちゃん 05/08 misc/Vending Machine/baumroll1234 tsukuyomi-chan ja Vending Machine 7 hours ago
Daily AlpacaHackに挑戦するつくよみちゃん 05/07 misc/Permission Denied 3/minaminao tsukuyomi-chan ja permission denied 3 7 hours ago
Writeup for Vending Machine nozokare ja Vending Machine 8 hours ago
Writeup for permission denied 3 nozokare ja permission denied 3 8 hours ago
Writeup for func-array nozokare ja func-array 8 hours ago

Rows:

crypto_666

Topic: PrimeReleased: Mar 25, 2026

108 solves

Crypto

Medium

kurenaif