@yu212 - AlpacaHack

yu212

@Yu_212_MC

AUTHORED CHALLENGES

OPEN DATE	CHALLENGE	SOLVES
2026/03/14	BINARY IN THE FUTURE. Rev	69 solves
2026/03/14	Red and Black Rev	5 solves
2026/03/14	javajail Misc	56 solves
2026/03/14	Double Hint RSA Crypto	30 solves
2026/03/14	Yajirin Rev Misc	1 solve
2026/03/14	Faulty AES Crypto	62 solves
2026/03/14	Expensive Operator Crypto	1 solve
2026/03/14	El Dorado Crypto	1 solve
2026/03/14	Dream of You Web	27 solves
2026/03/14	Fault Tolerance Py Misc	8 solves
2026/03/14	verified-msg Pwn Crypto	6 solves
2026/03/14	Single Hint RSA Crypto	120 solves
2026/03/14	Faulty SHA Crypto	2 solves
2026/03/14	Yet Another Injection Challenge Misc	29 solves
2026/03/14	RANDOM IN THE FUTURE. Crypto	28 solves
2026/01/29	Linear Coffee Generator Crypto	115 solves
2026/01/23	Paca Paca Authenticator Crypto	127 solves
2025/12/16	doloR Sit Amet Crypto	2 solves
2025/12/16	Noisy Channel Crypto	1 solve
2025/12/16	doloR Sit Amet Revenge Crypto	2 solves
2025/12/07	Fully Padded RSA Crypto	237 solves
2025/07/06	RSARSARSARSARSARSA Crypto	79 solves
2025/07/06	Flag Sharing Crypto	10 solves
2025/07/06	OTEC Crypto	39 solves
2025/07/06	Zero-sum game Crypto	4 solves

CTF HISTORY

START DATE	CTF	RANK
2025/07/20	AlpacaHack Round 13 (Crypto)	8 / 62
2025/05/17	AlpacaHack Round 11 (Web)	13 / 213
2025/03/23	AlpacaHack Round 10 (Pwn)	43 / 95
2025/03/01	SECCON CTF 13 決勝観戦CTF	101 / 233
2025/01/26	AlpacaHack Round 9 (Crypto)	20 / 138
2024/12/30	AlpacaHack Round 8 (Rev)	5 / 316
2024/11/30	AlpacaHack Round 7 (Web)	79 / 458
2024/11/03	AlpacaHack Round 6 (Pwn)	46 / 197
2024/10/12	AlpacaHack Round 5 (Crypto)	8 / 247
2024/09/15	AlpacaHack Round 3 (Crypto)	6 / 239
2024/09/01	AlpacaHack Round 2 (Web)	18 / 300
2024/08/18	AlpacaHack Round 1 (Pwn)	33 / 174

WRITEUPS

WRITEUP	CREATED AT
Author Writeup for tkbctf5 ja official BINARY IN THE FUTURE.	3 weeks ago
Writeup for HellCouple ja HellCouple	2 months ago
Author's Writeup for Linear Coffee Generator ja official Linear Coffee Generator	2 months ago
Author's Writeup for Paca Paca Authenticator ja official Paca Paca Authenticator	2 months ago
Writeup for Fully Padded RSA ja official Fully Padded RSA	4 months ago
AlpacaHack Round 12 (Crypto) 作問者writeup ja official Flag Sharing	9 months ago
Writeup for AlpacaHack Round 3 (Crypto) ja AlpacaHack Round 3 (Crypto)	last year
frozen cake 初心者向け解説 ja frozen cake	last year

SOLVED CHALLENGES

CHALLENGE	SOLVES	SOLVED AT
EncodeDecode Misc Daily AlpacaHack	85 solves	yesterday
Tar Uploader Web Daily AlpacaHack	100 solves	2 days ago
Dot Chain Misc Daily AlpacaHack	84 solves	2 days ago
encrypted-p Crypto Daily AlpacaHack	100 solves	2 days ago
Optimized expression Rev Daily AlpacaHack	115 solves	2 days ago
crypto_666 Crypto Daily AlpacaHack	105 solves	2 days ago
What's Next Web Daily AlpacaHack	110 solves	2 weeks ago
The past or the future? Crypto Daily AlpacaHack B-SIDE	33 solves	2 weeks ago
Haec Horrenda Misc Daily AlpacaHack B-SIDE	29 solves	2 weeks ago
UOUO FISH JAIL Misc Daily AlpacaHack B-SIDE	37 solves	2 weeks ago
memset note Pwn Daily AlpacaHack B-SIDE	44 solves	2 weeks ago
iwashi Crypto Daily AlpacaHack B-SIDE	37 solves	2 weeks ago
Resume Maker Web Daily AlpacaHack B-SIDE	53 solves	2 weeks ago
bloom Crypto Daily AlpacaHack	86 solves	2 weeks ago
vuln4vuln Pwn Daily AlpacaHack	96 solves	2 weeks ago
Alpacker Rev Daily AlpacaHack	78 solves	2 weeks ago
canary leak Pwn Daily AlpacaHack	106 solves	2 weeks ago
Flags for the FLAG Misc Daily AlpacaHack	149 solves	2 weeks ago
PPPPParse Misc Daily AlpacaHack	98 solves	2 weeks ago
Free Coupon Web Daily AlpacaHack	135 solves	2 weeks ago
The future path Crypto Daily AlpacaHack	92 solves	2 weeks ago
Another Login Challenge Web Daily AlpacaHack	123 solves	2 weeks ago
flag.txt Misc Daily AlpacaHack	110 solves	4 weeks ago
Heuristic IPPON Misc Daily AlpacaHack	167 solves	4 weeks ago
kappa overflow Pwn Daily AlpacaHack	121 solves	last month
Find XOR key Crypto Daily AlpacaHack	150 solves	last month
💯 Misc Daily AlpacaHack	116 solves	last month
FLAG OVER Misc Daily AlpacaHack	115 solves	last month
reiwa_rot13 Crypto SECCON CTF 13 Quals	29 solves	last month
guess.js Misc Daily AlpacaHack	103 solves	last month
high and low Crypto Daily AlpacaHack	87 solves	last month
magic number Misc Daily AlpacaHack	124 solves	last month
Alert my Flag Web Daily AlpacaHack	166 solves	last month
9️⃣ Misc Daily AlpacaHack B-SIDE	47 solves	last month
Flag Printer 2026 Misc Daily AlpacaHack	204 solves	last month
glibc's secret function Rev Daily AlpacaHack	195 solves	last month
Bars Web Daily AlpacaHack	298 solves	last month
pyjs Misc Daily AlpacaHack	82 solves	last month
Rock Paper Scissors Lizard Spock Web Daily AlpacaHack	96 solves	last month
One Byte Padding Oracle Attack Crypto Daily AlpacaHack	74 solves	last month
useful-gadget Pwn Daily AlpacaHack B-SIDE	46 solves	last month
Alpaca Rangers Web Daily AlpacaHack	148 solves	last month
hit-and-hit Misc Daily AlpacaHack	86 solves	last month
Alpaca Quest Rev Daily AlpacaHack	115 solves	last month
Noob programmer Pwn Daily AlpacaHack	105 solves	last month
Stealerusk Rev Daily AlpacaHack B-SIDE	45 solves	last month
CopperCopperCopper Crypto Daily AlpacaHack	92 solves	last month
Dancing Cursor Rev Misc Daily AlpacaHack	109 solves	last month
Pickle Loader Misc Daily AlpacaHack	117 solves	last month
Disappeared Pwn Daily AlpacaHack	115 solves	last month
ECRSA Crypto Daily AlpacaHack B-SIDE	45 solves	last month
wages of sin() Rev Misc Daily AlpacaHack	93 solves	last month
Alpaillier Crypto Daily AlpacaHack	117 solves	last month
ret2basics Pwn Daily AlpacaHack B-SIDE	44 solves	last month
You are being redirected Web Daily AlpacaHack	113 solves	last month
simple ROP Pwn Daily AlpacaHack	114 solves	last month
nc magic Misc Daily AlpacaHack	133 solves	last month
AAAAAAAAEEEEEEEESSSSSSSS Crypto Daily AlpacaHack	121 solves	last month
invisible-grep Misc Daily AlpacaHack B-SIDE	39 solves	2 months ago
destructuring Misc Daily AlpacaHack	143 solves	2 months ago
Alpaca-Llama Ranch Pwn Daily AlpacaHack	125 solves	2 months ago
Plz Login Web Daily AlpacaHack	225 solves	2 months ago
Compressor Misc Daily AlpacaHack	110 solves	2 months ago
misdirection Rev Daily AlpacaHack	161 solves	2 months ago
The World Misc Daily AlpacaHack	191 solves	2 months ago
HellCouple Crypto Daily AlpacaHack B-SIDE	70 solves	2 months ago
RRe_Time_Limiter Crypto Daily AlpacaHack	177 solves	2 months ago
Magic Engine Web Daily AlpacaHack	271 solves	2 months ago
read-a-binary Rev Daily AlpacaHack	225 solves	2 months ago
Substance Crypto Daily AlpacaHack	240 solves	2 months ago
Inu Profile Web Daily AlpacaHack B-SIDE	95 solves	2 months ago
optimal-sort Misc Daily AlpacaHack	104 solves	2 months ago
Linear Coffee Generator Crypto Daily AlpacaHack	115 solves	2 months ago
shellcode-101 Pwn Daily AlpacaHack	138 solves	2 months ago
No JS Web Daily AlpacaHack	132 solves	2 months ago
ToyPQC Crypto Daily AlpacaHack	108 solves	2 months ago
git gc Misc Daily AlpacaHack	154 solves	2 months ago
Stateless Auth Web Daily AlpacaHack	168 solves	2 months ago
Paca Paca Authenticator Crypto Daily AlpacaHack	127 solves	2 months ago
Bashrunner Misc Daily AlpacaHack	120 solves	2 months ago
Animal Viewer Web Daily AlpacaHack	154 solves	2 months ago
dockerstack Misc Daily AlpacaHack	180 solves	2 months ago
system-v Rev Daily AlpacaHack	118 solves	2 months ago
ChaChaCha Crypto Daily AlpacaHack	157 solves	2 months ago
dice roll Web Daily AlpacaHack	201 solves	2 months ago
Base Length Misc Daily AlpacaHack	157 solves	2 months ago
Short Writer Pwn Daily AlpacaHack	124 solves	2 months ago
Five Alpacas Crypto Daily AlpacaHack	196 solves	2 months ago
free-comment Misc Daily AlpacaHack	152 solves	2 months ago
I wanna be the Admin Web Daily AlpacaHack	283 solves	2 months ago
Basic Buffer Overflow Pwn Daily AlpacaHack	186 solves	3 months ago
crazython Rev Daily AlpacaHack	188 solves	3 months ago
RSA2026 Crypto Daily AlpacaHack	209 solves	3 months ago
SwapSwap Misc Daily AlpacaHack	286 solves	3 months ago
secret-table Web Daily AlpacaHack	270 solves	3 months ago
Square RSA Crypto Daily AlpacaHack	235 solves	3 months ago
jailiaj Misc Daily AlpacaHack	281 solves	3 months ago
Encoding Basics Misc Crypto Daily AlpacaHack	317 solves	3 months ago
Fushigi Crawler Web Daily AlpacaHack	343 solves	3 months ago
Ruby Flag Checker Rev Daily AlpacaHack	289 solves	3 months ago
super-tomato Crypto Daily AlpacaHack	388 solves	3 months ago
108 Misc Daily AlpacaHack	296 solves	3 months ago
RBG Crypto Daily AlpacaHack	123 solves	3 months ago
one-p-rsa Crypto Daily AlpacaHack	231 solves	3 months ago
cha-ll-enge Rev SECCON Beginners CTF 2024	158 solves	3 months ago
simpleoverwrite Pwn SECCON Beginners CTF 2024	197 solves	3 months ago
Useful Machine Rev Daily AlpacaHack	158 solves	3 months ago
Xmas Login Web Daily AlpacaHack	353 solves	3 months ago
cat3 Misc Daily AlpacaHack	221 solves	3 months ago
Rotten Beef Pwn Daily AlpacaHack	204 solves	3 months ago
Log Viewer Web Daily AlpacaHack	225 solves	3 months ago
RSA debug? Crypto Daily AlpacaHack	192 solves	3 months ago
omikuji Web Daily AlpacaHack	249 solves	3 months ago
alloc-101 Pwn Daily AlpacaHack	218 solves	3 months ago
Twilight Rev Daily AlpacaHack	230 solves	3 months ago
login-bonus Pwn Daily AlpacaHack	255 solves	3 months ago
🐈 Web Daily AlpacaHack	309 solves	3 months ago
Flag Printer 2100 Rev Daily AlpacaHack	246 solves	3 months ago
power_obfus_royalty Rev Daily AlpacaHack	209 solves	3 months ago
Safe Prime Crypto SECCON Beginners CTF 2024	253 solves	3 months ago
Sugoi Flag Checker Rev Daily AlpacaHack	204 solves	4 months ago
Alpaca Bank Web Daily AlpacaHack	331 solves	4 months ago
Read Assembly Rev Daily AlpacaHack	312 solves	4 months ago
hit-and-miss Misc Daily AlpacaHack	387 solves	4 months ago
Fully Padded RSA Crypto Daily AlpacaHack	237 solves	4 months ago
size limit Crypto Daily AlpacaHack	317 solves	4 months ago
simpleoverflow Pwn SECCON Beginners CTF 2024	505 solves	4 months ago
Integer Writer Pwn Daily AlpacaHack	325 solves	4 months ago
Leaked Flag Checker Rev Daily AlpacaHack	567 solves	4 months ago
Emojify Web Daily AlpacaHack	593 solves	4 months ago
a fact of CTF Crypto Daily AlpacaHack	883 solves	4 months ago
AlpacaHack 2100 Misc Daily AlpacaHack	1632 solves	4 months ago
Polynomial Puzzle Crypto AlpacaHack Round 13 (Crypto)	5 solves	8 months ago
Jerr0-day Crypto AlpacaHack Round 13 (Crypto)	15 solves	8 months ago
Jerry's flag checker Crypto AlpacaHack Round 13 (Crypto)	33 solves	8 months ago
Redirector Web AlpacaHack Round 11 (Web)	30 solves	11 months ago
Jackpot Web AlpacaHack Round 11 (Web)	163 solves	11 months ago
Kangaroo Pwn AlpacaHack Round 10 (Pwn)	66 solves	last year
ffmac Crypto AlpacaHack Round 9 (Crypto)	8 solves	last year
Equivalent Privacy Wired Crypto AlpacaHack Round 9 (Crypto)	9 solves	last year
RSAMPC Crypto AlpacaHack Round 9 (Crypto)	35 solves	last year
addprimes Crypto AlpacaHack Round 9 (Crypto)	27 solves	last year
subway Rev AlpacaHack Round 8 (Rev)	16 solves	last year
vcipher Rev AlpacaHack Round 8 (Rev)	29 solves	last year
hidden Rev AlpacaHack Round 8 (Rev)	71 solves	last year
masking tape Rev AlpacaHack Round 8 (Rev)	173 solves	last year
Alpaca Poll Web AlpacaHack Round 7 (Web)	129 solves	last year
Treasure Hunt Web AlpacaHack Round 7 (Web)	271 solves	last year
catcpy Pwn AlpacaHack Round 6 (Pwn)	146 solves	last year
inbound Pwn AlpacaHack Round 6 (Pwn)	207 solves	last year
GitFile Explorer Web zer0pts CTF 2022	48 solves	last year
Modern Rome Pwn zer0pts CTF 2022	24 solves	last year
Anti-Fermat Crypto zer0pts CTF 2022	30 solves	last year
NNNN Crypto AlpacaHack Round 5 (Crypto)	50 solves	last year
SchnorrLCG Crypto AlpacaHack Round 5 (Crypto)	23 solves	last year
XorshiftStream Crypto AlpacaHack Round 5 (Crypto)	65 solves	last year
Everything Silver Rev AlpacaHack Round 4 (Rev)	26 solves	last year
pytecode Rev AlpacaHack Round 4 (Rev)	26 solves	last year
Simple Flag Checker Rev AlpacaHack Round 4 (Rev)	127 solves	last year
A Dance of Add and Mul Crypto AlpacaHack Round 3 (Crypto)	74 solves	last year
Hat Trick Crypto AlpacaHack Round 3 (Crypto)	66 solves	last year
Rainbow Sweet Alchemist Crypto AlpacaHack Round 3 (Crypto)	124 solves	last year
qrime Crypto AlpacaHack Round 3 (Crypto)	253 solves	last year
ding-dong-ting-ping Crypto CakeCTF 2023	10 solves	last year
janken vs yoshiking 2 Crypto CakeCTF 2023	16 solves	last year
brand new crypto Crypto CakeCTF 2022	25 solves	last year
luau Rev CakeCTF 2022	34 solves	last year
CakeGEAR Web CakeCTF 2022	81 solves	last year
CaaS Web AlpacaHack Round 2 (Web)	93 solves	last year
Pico Note 1 Web AlpacaHack Round 2 (Web)	81 solves	last year
Simple Login Web AlpacaHack Round 2 (Web)	611 solves	last year
hexecho Pwn AlpacaHack Round 1 (Pwn)	114 solves	last year
echo Pwn AlpacaHack Round 1 (Pwn)	357 solves	last year
Cake Puzzle Rev CakeCTF 2023	20 solves	last year
mimikyu Rev zer0pts CTF 2023	15 solves	last year
read-write Pwn RTACTF 2023 Spring	41 solves	last year
1R-AES Crypto RTACTF 2023 Spring	17 solves	last year
Collision-DES Crypto RTACTF 2023 Spring	37 solves	last year
write Pwn RTACTF 2023 Spring	85 solves	last year
before-write Pwn RTACTF 2023 Spring	162 solves	last year
Reused-AES Crypto RTACTF 2023 Spring	33 solves	last year
XOR-CBC Crypto RTACTF 2023 Spring	77 solves	last year
Welcome Misc	1544 solves	last year
SquareRNG Crypto zer0pts CTF 2023	15 solves	last year
easy_factoring Crypto zer0pts CTF 2023	29 solves	last year
TOWFL Web Cheat CakeCTF 2023	51 solves	last year
decompile me Rev zer0pts CTF 2023	48 solves	last year
vtable4b Pwn CakeCTF 2023	61 solves	last year
nimrev Rev CakeCTF 2022	79 solves	last year
bofww Pwn CakeCTF 2023	38 solves	last year
frozen cake Crypto CakeCTF 2022	71 solves	last year
simple signature Crypto CakeCTF 2023	28 solves	last year
Country DB Web CakeCTF 2023	224 solves	last year

Only archived challenges are displayed here.