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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!

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

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

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Today's Challenge
rsk0315
Decimal float 101.0
Misc
Medium
17 solves
Submissions (latest 3)
itsuki-t

SOLVED!

Jun 25, 8:26 PM

pppp4649

SOLVED!

Jun 25, 7:44 PM

kurgm

SOLVED!

Jun 25, 5:32 PM

Leaderboard

Try the first challenge

Is this your first CTF? Let's begin by tackling the first challenge released on Daily AlpacaHack.

View challenge
admin
AlpacaHack 2100
Misc
Welcome🌱
1,915 solves
Upcoming challenges reveal the , , and in advance.
Prev

Jun 2026

Next
Solved
Unsolved
Upcoming
Mon
Tue
Wed
Thu
Fri
Sat
Sun
1
admin
Half-Year Recap
Misc
Welcome🌱
244 solves
2
minaminaominaminao
Cache Me If You Can
Web
Easy🌱
204 solves
3
minaminaominaminao
vm1
Misc
Medium
98 solves
4
pppp4649pppp4649
Small e
Crypto
Easy🌱
137 solves
5
minaminaominaminao
RPS GAME
Misc
Crypto
Medium
99 solves
6
nozokare
Flag for localhost
Web
Easy🌱
171 solves
7
tan90909090tan90909090
C++ flag checker
Rev
Hard
86 solves
8
shiragishiragi
Guess IP
Misc
Easy🌱
143 solves
9
nozokare
A Piece of DHKE
Crypto
Medium
82 solves
10
shiragishiragi
chmod-swapper
Misc
Medium
85 solves
11
tchentchen
Alpaca Certification
Web
Easy🌱
159 solves
12
rsk0315
Floating Equality
Misc
Medium
90 solves
13
pppp4649pppp4649
Elliptic Equation
Crypto
Hard
59 solves
14
tchentchen
CAuth
Web
Hard
65 solves
15
minaminaominaminao
SITE/2
Web
Easy🌱
118 solves
16
tan90909090tan90909090
Xored PNG
Misc
Medium
87 solves
17
tchentchen
Looks like Alpacahack
Web
Medium
81 solves
18
shiragishiragi
Catrunner 2
Misc
Easy🌱
105 solves
19
minaminaominaminao
Flag Printer 20XX
Misc
Medium
63 solves
20
nozokare
xorshift521
Crypto
Hard
54 solves
21
k0080k0080
what-is-my-size
Pwn
Hard
63 solves
22
minaminaominaminao
✌️✌️✌️
Crypto
Easy🌱
88 solves
23
tchentchen
Secret Renderer
Web
Medium
79 solves
24
kanonkanon
honk the klaxon
Crypto
Medium
53 solves
25
colza
voyage
Misc
Easy🌱
84 solves
26
rsk0315
Decimal float 101.0
Misc
Medium
17 solves
27
bubu
Planned topicClient-Side
Web
Hard
28
Planned topicTBA
Pwn
Hard
29
Coming soon
30
Coming soon
2
Planned topicMathematics
Crypto
Easy🌱
3
Coming soon
4
Planned topicJavaScript
Rev
Medium
5
Coming soon

Want a harder challenge?

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Writeups

Daily AlpacaHackに挑戦するつくよみちゃん 06/25/voyage/colza

tsukuyomi-chan

ja
voyage

5 hours ago

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

minaminao

Writeup for ✌️✌️✌️

author
ja

2026/06/22 17:14

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

tadanobutubutu

Writeup for ✌️✌️✌️

tadanobutubutu

Writeup for what-is-my-size

Rows:

Flag for localhost

Topic: HTTPReleased: Jun 6, 2026

171 solves
Web
Easy🌱3.5

by

nozokare

USER

SOLVED AT

tai

10 hours ago

11 hours ago

11 hours ago

11 hours ago

11 hours ago

11 hours ago

11 hours ago

12 hours ago

12 hours ago

12 hours ago

13 hours ago

14 hours ago

2026/06/24 18:16

2026/06/24 16:10

2026/06/24 13:45

2026/06/22 23:27

2026/06/22 08:20

2026/06/22 04:43

2026/06/21 12:08

2026/06/21 01:54

2026/06/20 14:42

2026/06/20 11:34

2026/06/20 08:35

2026/06/20 05:15

2026/06/19 10:04

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descriptionsolveswriteups