B-SIDE

A daily CTF challenge with a fun new puzzle every day

What is B-SIDE?

This side program features challenges with a different flavor from Daily AlpacaHack. We publish one harder or more unconventional challenge every few days.

Join Anytime

Solve each challenge within its time window 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 the challenge period has ended.

New to CTFs?

This program features higher difficulty and unconventional challenges. Try the beginner-friendly Daily AlpacaHack first to warm up.

View Daily AlpacaHack

Solve stats

/31

No solved challenges yet.

Today's Challenge

Submissions (latest 3)

mti

SOLVED!

May 25, 5:57 PM

tyage

SOLVED!

May 25, 1:52 PM

kowerkoint

SOLVED!

May 25, 1:05 AM

Leaderboard

Period

Upcoming challenges reveal the , , and in advance.

May 2026

Solved

Unsolved

Upcoming

Mon

Tue

Wed

Thu

Fri

Sat

Sun

iwancof

Blind Sort

Pwn

Very Very Hard

14 solves

1-3

kakur41

simple ROP?

Pwn

Hard

36 solves

4-7

minaminao

The Sandbox

Misc

Web

Very Hard

26 solves

8-11

k0080

swap-system

Pwn

Very Hard

24 solves

k0080

swap-system

Pwn

Very Hard

24 solves

12-15

tchen

Iframe Sandbox

Web

Very Hard

28 solves

16-19

minaminao

Secret Fail

Misc

Very Hard

20 solves

minaminao

Secret Fail

Misc

Very Hard

20 solves

20-23

kanon

Hennessy

Crypto

Very Hard

22 solves

24-26

minaminao

Git Note

Misc

Hard

16 solves

minaminao

Git Note

Misc

Hard

16 solves

27-29

tchen

Planned topicXSS

Web

Hard

Coming soon

Go to Daily AlpacaHack

Writeups

Writeup for Resume Maker

hxuu

Resume Maker

2026/05/23 15:58

Writeup for Bulk Note

hxuu

Bulk Note

2026/05/22 23:25

Writeup for Iframe Sandbox

hxuu

Iframe Sandbox

2026/05/21 20:28

Writeup for Secret Fail

bsvac

Secret Fail

2026/05/20 01:56

Writeup for Iframe Sandbox

nick

Iframe Sandbox

2026/05/17 09:19

Writeup for The Sandbox

kurgm

The Sandbox

2026/05/17 06:30

Writeup for swap-system

kurokane-isumi

swap-system

2026/05/14 14:27

Writeup for The Sandbox

kirehash

The Sandbox

2026/05/14 11:39

Writeup for The Sandbox

umineko

The Sandbox

2026/05/10 12:56

Writeup for Life is probably full of bugs

pppp4649

author

Life is probably full of bugs

2026/05/10 01:27

Rows:

The past or the future?

Topic: RNGReleased: Mar 23, 2026

35 solves

Crypto

Hard

pppp4649

Tags

USER	SOLVED AT
n0v4	2026/04/28 11:57
chocorusk	2026/04/16 05:57
kitatai	2026/04/11 12:37
moz99	2026/03/28 04:44
n0name	2026/03/25 14:24
prime-1019	2026/03/25 13:37
shiragi	2026/03/25 09:44
tchen	2026/03/24 23:13
colza	2026/03/24 15:28
tyage	2026/03/24 12:49
blackade	2026/03/24 12:04
fjkl1245p	2026/03/24 09:33
nozokare	2026/03/23 13:02
nex	2026/03/23 12:51
nomeaning	2026/03/23 12:45
yu212	2026/03/23 12:20
ahnmo	2026/03/23 06:47
mak0tan	2026/03/23 02:41
hiikunz	2026/03/23 01:02
kakur41	2026/03/23 00:54
bsvac	2026/03/23 00:48
syn9	2026/03/22 23:07
cyanos	2026/03/22 22:44
rsk0315	2026/03/22 18:34
dediamondpro	2026/03/22 18:02

Rows:

description solves writeups