B-SIDE
A CTF challenge series with fun puzzles to enjoy every day — B-SIDE
What is B-SIDE?
This side program features challenges with a different flavor from Daily AlpacaHack. We publish harder or more unconventional challenges from time to time.
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.
Today's ChallengeNo challenge is currently active.
Leaderboard
Period
Upcoming challenges reveal the , , and in advance. 
st98 
k0080 
chocorusk
Feb 2026
NextSolved
Unsolved
Upcoming
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1-4st98
st98st985-8chocorusk
chocorusk9-12
minaminao
minaminao13-16k0080
k0080k008017-20
theoremoon
theoremoon21-24chocorusk
chocoruskchocorusk25-28k0080
k00801-4
