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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Today's Challenge

Submissions (latest 3)

toomer

SOLVED!

May 21, 5:31 PM

panya

SOLVED!

May 21, 5:24 PM

itsuki-t

SOLVED!

May 21, 5:04 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.

May 2026

Solved

Unsolved

Upcoming

Mon

Tue

Wed

Thu

Fri

Sat

Sun

shiragi

Unrevealed TXT

Misc

Easy🌱

127 solves

serioton

unheard

Misc

Medium

77 solves

minaminao

permission denied

Misc

Hard

80 solves

minaminao

permission denied 2

Misc

Medium

81 solves

admin

Alpaca++

Misc

Welcome🌱

239 solves

tchen

Alpaca Rangers 2

Web

Easy🌱

202 solves

pppp4649

Small N

Crypto

Easy🌱

152 solves

hiikunz

secret-table-2

Web

Medium

144 solves

serioton

do the math

Misc

Medium

113 solves

trimscash

func-array

Pwn

Easy🌱

141 solves

minaminao

permission denied 3

Misc

Medium

112 solves

baumroll1234

Vending Machine

Misc

Easy🌱

171 solves

hiikunz

reused n

Crypto

Medium

113 solves

rsk0315

Bounds Checking

Pwn

Hard

84 solves

serioton

Mirage

Rev

Easy🌱

120 solves

minaminao

hidden service

Misc

Medium

101 solves

tchen

Super Short Python Golf

Misc

Medium

115 solves

minaminao

Equation Cipher

Crypto

Medium

99 solves

tan90909090

curl as a service

Web

Misc

Medium

109 solves

k0080

Please Link This

Pwn

Hard

73 solves

tan90909090

curl as a service 2

Web

Misc

Hard

85 solves

shiragi

Flag for Switch

Web

Easy🌱

143 solves

pppp4649

Small d

Crypto

Medium

97 solves

tchen

Kakuzuke

Web

Medium

98 solves

kakur41

Python:Impossible

Misc

Medium

92 solves

nozokare

Time Travelers' OTP

Web

Medium

18 solves

minaminao

Planned topicNumber Theory

Crypto

Hard

k0080

Planned topicCUDA

Rev

Hard

minaminao

Planned topicPath Traversal

Misc

Easy🌱

baumroll1234

Planned topicRSA

Crypto

Medium

Coming soon

rsk0315

Planned topicXSS

Web

Hard

ptr-yudai

Planned topicStack

Pwn

Hard

Want a harder challenge?

Go to B-SIDE

Writeups

Daily AlpacaHackに挑戦するつくよみちゃん 05/21 misc/Python: Impossible/kakur41

tsukuyomi-chan

Python:Impossible

27 minutes ago

Writeup for Python:Impossible

tadanobutubutu

Python:Impossible

2 hours ago

Writeup for Kakuzuke

tadanobutubutu

Kakuzuke

22 hours ago

Daily AlpacaHackに挑戦するつくよみちゃん 05/20 web/Kakuzuke/tchen

tsukuyomi-chan

Kakuzuke

2026/05/20 16:03

Writeup for Kakuzuke

goroshirow

Kakuzuke

2026/05/20 15:39

Writeup for Emojify

paulayground

Emojify

2026/05/20 15:17

Writeup for Small d

tadanobutubutu

Small d

2026/05/19 16:03

Daily AlpacaHackに挑戦するつくよみちゃん 05/19 crypto/small d/pppp4649

tsukuyomi-chan

Small d

2026/05/19 16:00

Writeup for Small d

goroshirow

Small d

2026/05/19 15:08

Writeup for Daily AlpacaHack 5/11-5/17

labpump

curl as a service 2

2026/05/19 12:12

Rows:

Time Travelers' OTP

Topic: One-Time PasswordReleased: May 22, 2026

18 solves

Web

Medium

nozokare

USER	SOLVED AT
toomer	15 minutes ago
panya	22 minutes ago
itsuki-t	42 minutes ago
shiro	1 hour ago
edwowmath	1 hour ago
tad	1 hour ago
cyanos	1 hour ago
rsk0315	2 hours ago
mak0tan	2 hours ago
kurgm	2 hours ago
nanashiku	2 hours ago
cocoa	2 hours ago
tadanobutubutu	2 hours ago
redpo	2 hours ago
bsvac	2 hours ago
syn9	2 hours ago
mg7x	2 hours ago
umineko	2 hours ago

Rows:

description solves