Curated, category-first. A merge of the operator's frozen solved challenges (from the main
workspace) and imported author solutions from the official SekaiCTF archives. Each item is a
challenge folder (meta.yml+writeup/ or an imported writeup.md+solution/).
Also here (not items): playbooks/ — per-discipline cheat sheets · lessons.md · resources.md.
Search with toolkit/refsearch <query> (semantic bge-m3 RAG over this tree, lexical fallback).
Totals: 667 reference items across 11 categories.
- Prompt-injection / guardrail-bypass library
- Avocado Price Prediction
- Duality in All Things
- If Models Could Dream
- Jurgen's Revenge
- pickled-onions
- SABLE
- Gnosis Unsafe
- イベント! (Ibennto!) · SekaiCTF
- Locker
- Meta Staking
- Play to Earn · SekaiCTF
- Race
- Sekai Lending · SekaiCTF
- Sekai Meme Launcher · SekaiCTF
- Stray Cat · SekaiCTF
- SURVIVE · SekaiCTF
- チケットマスター (Ticket Master) · SekaiCTF
- ZOO · SekaiCTF
- AE-no-S
- AES confusion
- Alter Ego · SekaiCTF
- APES · SekaiCTF
- Baby Feistel
- Baby RSA
- babyRSA
- Blind Mouse Challenge
- caexor
- carry-the-flame
- cryptoGRAPHy 1 · SekaiCTF
- cryptoGRAPHy 2 · SekaiCTF
- cryptoGRAPHy 3 · SekaiCTF
- Diffecient · SekaiCTF
- Diffecient · SekaiCTF
- Diffecientwo · SekaiCTF
- Dlog24
- dot
- EncryptSvc2
- Entry
- EZMaze · SekaiCTF
- EZMaze · SekaiCTF
- FaILProof · SekaiCTF
- FaILProof · SekaiCTF
- FaILProof Revenge · SekaiCTF
- FaILProof Revenge · SekaiCTF
- filter_flag
- Gambler's Fallacy
- はやぶさ · SekaiCTF
- HMAC-CRC
- I Dream of Genni · SekaiCTF
- Iterated Polynomials
- Law and Order · SekaiCTF
- lazy-bigrams
- Leaked d
- Learning With Mistakes
- LENcrypt
- マスタースパーク (Master Spark) · SekaiCTF
- MAT247
- MAT347
- Meow Log Meow Log Meow E
- misdirection
- Noisier CRC · SekaiCTF
- Noisy CRC · SekaiCTF
- not-so-lazy-trigrams
- Old Crypto Server
- Orca
- otp
- otp2
- plane-or-exchange
- potp
- Protect The Vaccine
- Radio Station Apocalypse
- RandSubWare · SekaiCTF
- RC4 Signing Scheme
- Ring3 Hello
- Robust CBC · SekaiCTF
- Robust CBC · SekaiCTF
- Rotor Cipher
- RSA Basics and Long Long Encrypt
- RSA stream
- RSC
- Safe Xor
- Secure Banking
- Secure Image Encryption · SekaiCTF
- Secure Image Encryption · SekaiCTF
- sisyphus
- six seven
- six seven again
- slow-gold
- smart
- smol cats
- Some Trick · SekaiCTF
- spreading-secrets
- √163 · SekaiCTF
- Squares vs. Cubes · SekaiCTF
- SSSS · SekaiCTF
- Stirrer
- Sum-O-Primes
- the-2000s-american-housing-crisis
- The C(hallenge) of C(rypto)P(als)
- the-clock
- Time Capsule · SekaiCTF
- Time Capsule · SekaiCTF
- ttyspin
- unfairy-ring · SekaiCTF
- unfairy-ring++ · SekaiCTF
- UofT LFSR Labyrinth
- UTCTF 2020 Hill
- Whos My Waifu
- zerodaycrypto · SekaiCTF
- A Nation State Musical
- APTV3R4_STRIKES_AGAIN
- Baby Exfil
- Between 0&1
- Big Brother Secrets
- Blind Infection 1 · SekaiCTF
- Blind Infection 1 · SekaiCTF
- Broken Converter · SekaiCTF
- Broken Converter · SekaiCTF
- Chiaroscuro
- Clickity Clack
- Crimewatch
- DEFCON Invitation · SekaiCTF
- Dumpster Dive · SekaiCTF
- Eval Me · SekaiCTF
- Exfiltration
- File Transfer Protocol
- flag Mono · SekaiCTF
- flag Mono · SekaiCTF
- Fort Knockies
- Grey Yuumi
- Infected · SekaiCTF
- Jarred-1
- Jarred-2
- Jarred-3
- Memory Road
- My Favourite Music
- My Pokemon Card is Fake!
- Nefarious Bits
- Pwned
- Recycling Bin
- Sensitive
- sharpturn
- Special Stego I - 3D Room
- Special Stego II - Picturesque Mountains
- Special Stego III - A Child's Drawing
- Special Stego IV - Sunset and Mountains
- Symbolic Needs 1 · SekaiCTF
- Symbolic Needs 1 · SekaiCTF
- The WiFi Challenge
- Visual Noise
- Wanna PK
- diceisyou · imported
- Escape the battlefield · imported
- Lost Dungeon · imported
- shooter · imported
- Shall We Play A Game? · imported
- Bootloader
- Bricked Up
- Catcore
- Hornet 9 Homework
- Hornet Revenge
- Leaky Pin
- Name
- Secure Memory
- Serialous
- Shooting Flags
- Short
- 13-piece Puzzle
- 67
- A letter from the Human Resource Management · SekaiCTF
- actualbeepboop
- An old soviet terminal
- AuthLab
- AuthLab1.1
- Baby Cake
- Backdoored
- Borpa · SekaiCTF
- Borpa · SekaiCTF
- brrrrrrrrrr
- calcql · SekaiCTF
- cat bomb!
- checkin
- Codex Computer Use
- Console Port · SekaiCTF
- Console Port · SekaiCTF
- ContinuousNim
- CTFaaS - CTFs as a Service!
- discord
- Discord Insanity Check
- Discrepancy · SekaiCTF
- Elden Ring
- Electric Box · SekaiCTF
- Electric Box · SekaiCTF
- Encryption Service
- endians
- error-correction
- Face Unlock
- feedback
- Feedback
- File Upload
- flag-irl
- Fluffy 2.5
- Fluffy I
- Fluffy II
- Fluffy III
- Formula 739137
- FoxHunt
- game
- Ghost
- good-vibes
- grammar
- greyhats-server
- Guess The Number
- Hijacker · SekaiCTF
- How QueeR
- I love this world · SekaiCTF
- IP Camera
- Just Another Pickle Jail · SekaiCTF
- K&K Training Room
- leadgate
- Let's Play Osu!Mania · SekaiCTF
- Let's Play Osu!Mania · SekaiCTF
- Literal Eval · SekaiCTF
- literally-1984
- Logical Computers
- Lottery
- lpmc
- Many Paths
- Matryoshka · SekaiCTF
- Matryoshka · SekaiCTF
- Miku Jail · SekaiCTF
- Miku vs. Machine · SekaiCTF
- Mikusweeper · SekaiCTF
- Mind Calculator · SekaiCTF
- Mind Calculator · SekaiCTF
- MusicalTalent
- Nokotan · SekaiCTF
- Nokotan's Antler Tines · SekaiCTF
- Nokotan's Arcade · SekaiCTF
- Nokotan's Guidance · SekaiCTF
- not-just-a-hobby
- notefactory
- Nothing Ever Changes
- Pafs · SekaiCTF
- Pafs · SekaiCTF
- pi_master
- Pi Master
- [Blockchain] Play for Free · SekaiCTF
- Poolside Paradise Or Criminal Hideout
- Project Sekai Event Planner · SekaiCTF
- Purple Sheep And The Apple Rush · SekaiCTF
- pytecoding
- QR God · SekaiCTF
- Railgun · SekaiCTF
- Raising Morales
- Random Song · SekaiCTF
- Random Song · SekaiCTF
- [Blockchain] Re-Remix · SekaiCTF
- Reverse Wordle
- RF Signal Analysis
- Ring4 What Time Is It
- Ring5 Misc-3: Add to Your Reading List
- rules
- Sanity Check
- Say My Name
- Sekai Bank - Transaction · SekaiCTF
- SekaiCTFCorp · SekaiCTF
- Shellcode Generator
- Smartest Nation
- SSH · SekaiCTF
- StackVm
- survey
- Sus · SekaiCTF
- Sus · SekaiCTF
- suspicious neighbour
- THE 2.0
- The Hacker Experience
- Tones 2
- Training Shooting Flags
- TVOIT
- Vibe Code
- Vocaloid Heardle · SekaiCTF
- Vocaloid Heardle · SekaiCTF
- Wait a minute
- welcome
- Wiki Game · SekaiCTF
- yaps
- A Bird in the Hand
- adventure
- AES AEAD
- Aircon
- Algorithm Multitool · SekaiCTF
- ALU
- arraystore2
- baby-bof
- BabyARMROP
- Baby bof
- babyheap
- babyrop
- BFS · SekaiCTF
- BFS · SekaiCTF
- bop it
- butterfly
- bvar
- BYOB
- bytecrusher
- Calculator
- canary
- CArot
- Complete Me
- Context Reducer · SekaiCTF
- Cookie Library
- Cookie Monster
- coopy
- COP
- cornelslop
- Cosmic Ray · SekaiCTF
- cowsaymoo
- dbench_jumbf
- Deceitful Treasure
- dreamfactory
- easyoob
- easyoob2
- easyuaf
- EasyWrite
- extended-eBPF
- El Primo
- Electrostar 1
- elite ball knowledge
- Epic Boss Fight
- External
- Extraordinary
- fast-af-calculator
- Feedback Portal
- Filelen
- filtered
- Flippidy
- Futuristic Secure Bulletin
- G1B50N-1
- garden
- gets · SekaiCTF
- gets · SekaiCTF
- GFT · SekaiCTF
- GFT · SekaiCTF
- Gonnegtions
- Hello World Setup · SekaiCTF
- Hello World Setup · SekaiCTF
- Hibana · SekaiCTF
- histogram
- Hopscotch
- Horsepower
- House of sice
- insecure_seccomp
- Its A Real Heap Challenge
- JIGROP Puzzle
- jop
- KitEngine
- Late for School
- Learning OOP · SekaiCTF
- Life Simulator 2 · SekaiCTF
- lil wishes db
- listbook
- MasterWang
- memecat
- message-store
- Mindgames 1
- Mindgames 2
- Minister_Mediului
- Moving signals
- msgbox
- mspaint
- my first echo server
- naughty
- Network Tools · SekaiCTF
- newPaX
- no canary
- NO-OUTPUT
- nolibc · SekaiCTF
- Notification · SekaiCTF
- oomg_space
- OSRS
- ourukla
- Outdated · SekaiCTF
- overly simplified pwn challenge
- overly simplified pwn challenge
- Padoru Padoru
- panda-food
- POMO
- Poopoo Pants
- Poopoo Pants
- Process Flipper · SekaiCTF
- pwn the toilet
- r/WholesomeCopypasta
- rat2libzz
- re:life
- Read me a book
- ready_for_xmas
- real heap challenge
- real heap challenge
- refraction
- Return to what
- Return to what's revenge
- Robust Orbital Postal Service
- roppity
- roprop
- rrop
- Sand Castles
- Sanity Check
- Sanity Check
- santa
- Save Me · SekaiCTF
- Save Me · SekaiCTF
- ScrabASM
- Seashells
- Secure Blob Runner
- ShadowStuck
- should've had a v8
- sick
- Slay the Dragon 2
- slithery
- speedpwn · SekaiCTF
- speedpwn 2 · SekaiCTF
- split
- Stack BOF School
- Stop
- Super Secure Blob Runner
- super secure blob runner
- Syscall Phobia
- Task Tracker
- tcademy
- Text Sender · SekaiCTF
- The Bards' Fail
- [Blockchain] The Bidding · SekaiCTF
- The Forge
- The Motorala 1
- The Motorala 2
- The Mound
- The Trial Author
- this-is-how-you-pwn-the-time-war
- thoughts
- tic-tac-no
- Top Secret Portal
- Transactions
- Transactions II
- Turboflan
- uc_baaaby
- Umiyuri Kaikeitan · SekaiCTF
- uprobe
- UTCTF 2020 BOF
- vkfs · SekaiCTF
- warmup
- Warmup
- Warmup
- WatsonsFunhouse
- | Author | Difficulty | Points | Solves | · SekaiCTF
- Wordpocalypse
- Write me a book
- xmm_dist
- 3d-maze
- A Complicated Secret
- A Sky Full of Stars
- Adventure Time
- Alchemy Master · SekaiCTF
- angry_robot
- another-onion
- aperfectlynormalapp
- Baby Chicken · SekaiCTF
- Baby Chicken · SekaiCTF
- Baby (Obfuscated) Flag Checker
- baby_mult
- baby-re
- bedtime
- Beep Boop
- Berserk · SekaiCTF
- Berserk · SekaiCTF
- Bring Your Own Program
- Conquest of Camelot · SekaiCTF
- Crack Me · SekaiCTF
- Dynamic Library
- Easy as GDB
- explorer
- Flag checker part 1
- Flag checker v1 + v2
- flag-finder
- Flag Roulette
- ghidra gangster edition
- go-chan
- gogo
- Gondola · SekaiCTF
- Gopher's Adventure!
- Guardians Of The Kernel · SekaiCTF
- Haachama Cooking
- Haystack
- helm hell
- Hungry Ghost Festival
- hungry ghost festival
- Hurry Up! Wait!
- interpreter-required
- Is this really python?
- lactf-1986
- Let's Get Dynamic
- lights-out
- locked-in
- Login
- Magnum Opus · SekaiCTF
- Master Rev
- Matrix Lab 1 · SekaiCTF
- Matrix Lab 1 · SekaiCTF
- Matrix Lab 2 · SekaiCTF
- Matrix Lab 2 · SekaiCTF
- Matrix Lab 3 · SekaiCTF
- Matrix Lab 3 · SekaiCTF
- mazeware
- Memory Game (Part 2)
- meow-ware
- Miku Music Machine · SekaiCTF
- ML Connoisseur
- my-greycat
- Neon Deceit
- No F No Respects
- Number Game
- ooo
- overly simplified rev challenge
- overly simplified rev challenge
- Perfect Match X-treme · SekaiCTF
- Perfect Match X-treme · SekaiCTF
- Powershelly
- Prove Your Worth
- puzzled
- puzzled
- Puzzles
- Random Secure or Secure Random
- Ransomware
- Re
- reflection
- Rolling My Own
- Sahuang Flag Checker · SekaiCTF
- Satisfiability
- Secure Computing · SekaiCTF
- sekai-craft · SekaiCTF
- Sekai Licensing · SekaiCTF
- Sekai Bank - Signature · SekaiCTF
- Serpentine
- Simple Windows Flag Checker
- spidr
- starless-c
- Storytime: The Shocking Conclusion
- Storytime: The Tragic Interlude
- Super Secure Sipher
- Symbol of Hope
- Teyvat Travel Guide · SekaiCTF
- the-fish
- the-three-sat-problem
- Trailblazer
- Wait, this isn't C
- web-azzembly
- What do the numbas mean
- What in Ternation · SekaiCTF
- Will u Accept Some Magic?
- x and or
- X64 Extension · SekaiCTF
- YALA Part 1
- A4 Toilet Paper
- ad-note
- ad-note-revenge
- Admin at work
- aimfactory
- aimfactory
- append-note
- Babier CSP
- Baby Flask
- Baby0Day
- Battleships
- blogler
- bobles-and-narnes
- Bottle Poem · SekaiCTF
- Bottle Poem · SekaiCTF
- Captivating Canvas Contraption · SekaiCTF
- Cells at work
- Chunky · SekaiCTF
- clawcha
- Crab Commodities · SekaiCTF
- Crab Commodities · SekaiCTF
- customProtocol
- diceminer
- dicewallet
- English or Spanish
- extend-note
- Fancy Web · SekaiCTF
- Firewall
- Flag Shop
- Frog-WAF · SekaiCTF
- Funny lfr · SekaiCTF
- glotq
- Go File Yourself
- Go Going Goen
- Golf Jail · SekaiCTF
- Grapache
- GreyCat Game
- GreyCTF Survey (REAL!)
- Greyhats Gallery
- Hi Doggy
- hopefully good sourceless web
- hqli-me · SekaiCTF
- htmlsandbox · SekaiCTF
- Intruder · SekaiCTF
- Issues · SekaiCTF
- Issues · SekaiCTF
- job-board
- kitty
- LACTF 2026 Admin Bot
- lactf-invoice-generator
- Leakless Note · SekaiCTF
- lookup · SekaiCTF
- mirror-temple
- mirror-temple-b-side
- Missing Flavortext
- mutation mutation
- My Flask App · SekaiCTF
- MyHtmlSan
- narnes-and-bobles
- NDWPP · SekaiCTF
- No Quotes
- No Quotes 2
- No Quotes 3
- Notebook Viewer · SekaiCTF
- Obligatory Calc · SekaiCTF
- Obligatory Calc · SekaiCTF
- oops-blog
- Pasteboard
- Personal Blog
- Pollution
- Project Ares
- Proto Grader
- Quotes
- Red Flag
- rednote · SekaiCTF
- rei
- Report Me
- Safelist · SekaiCTF
- Safelist · SekaiCTF
- Scanner Service · SekaiCTF
- SeeTeeEffedIn
- Sekai Game Start · SekaiCTF
- Sekai Game Start · SekaiCTF
- Shero
- single-trust
- Submit your Homework
- Supreme PDF Hoster
- Tagless · SekaiCTF
- Take Note Of This
- Tangerine Stan
- the-trial
- Unrealistic Client-Side Challenge - Flag 1
- Unrealistic Client-Side Challenge - Flag 2
- vite · SekaiCTF
- Vulnerability Research
- WAF Bypass
- Warm Cockles
- Web Utils
- Wildest Dream
- Xtreme Static Sites