CTF challenges & writeups

75 challenges in family ⊕ crypto:prng ✕ clear · browse all techniques

Challenge	CTF	Weight	Category	Has
ransomwaRE #malware-reversing #date-seeded-key #aes-ctr #keystream-reuse	CSAW 2021 Quals	20.54	Reverse	files wu 2
benaloh #benaloh-cryptosystem #lcg-nonce #higher-residuosity	DiceCTF 2021	24.82	Crypto	files wu 1
Foliage #prng-reconstruction	ImaginaryCTF 2021	–	Reverse	files wu 1
I_Hate_Python #fixed-seed-prng	MetaCTF 2021	–	Reverse	files wu 2
DiceRoll #mt19937-prediction	NahamCon 2021	24.98	Crypto	files wu 3
Fake_Medallion #quantum-cloning #mersenne-twister #quantum-money	PlaidCTF 2021	99.64	Crypto	files wu 1
Sign_Wars #ecdsa #biased-nonce #lattice #mt19937	SECCON 2021	–	Crypto	files wu 1
pwgen #lcg #z3	TAMUctf 2021	–	Crypto	files wu 1
import_numpy_as_MT #numpy-mt19937 #seed-bruteforce #aes-cbc	Zh3r0 2021	–	Crypto	files src wu 1
real_mersenne #mt19937 #state-recovery #float-prediction	Zh3r0 2021	–	Crypto	files src wu 2
twist_and_shout #mt19937 #state-recovery #untwist	Zh3r0 2021	–	Crypto	files src wu 2
roulette_wheel #c++-reversing #predictable-rng	b01lers 2021	22.99	Reverse	files wu 2
weenie_hut_general #predictable-prng #fixed-srand-seed	b01lers 2021	22.99	Reverse	files wu 2
LCG_k #ecdsa #lcg-nonce #signature-forgery	corCTF 2021	24.92	Crypto	files src wu 1
TonyAndJames #python-mersenne-twister #seed-recovery #xor-keystream	darkCON 2021	24.06	Crypto	files wu 3
Seed_of_Life #mt19937-seed-bruteforce	idekCTF 2021	24.56	Crypto	files wu 1
Another_Login #srand-seed-prediction	m0leCon 2021 Quals	24.55	Pwn	files wu 1
signme #rsa #signature-forgery #weak-prng #seed-bruteforce	zer0pts 2021	24.56	Crypto	files wu 1
CookieMonster #format-string #time-seeded-canary-bypass #stack-buffer-overflow	DawgCTF 2020	23.29	Misc	files wu 3
seed-sPRiNG #srand-time-seed #prng-prediction	picoCTF 2019	–	Pwn	files wu 1
lucky #prng-seed-overwrite #rand-prediction #buffer-overflow	Defcamp 2018 Quals	18.75	Misc	files wu 3
Back_to_the_past #srand-time-seed #lcg #bruteforce	PwnMe 2025 Quals	24.95	Reverse	files wu 1
Mafia_at_the_end_2 #smart-contract #predictable-rng #storage-read	PwnMe 2025 Quals	24.95	Misc	files wu 1
Block_construction #aes-ecb #predictable-rng-seed	BraekerCTF 2024	24.72	Crypto	files wu 1
MediumExpectations #python-random-prediction	BSidesTLV 2022	23.94	Crypto	files wu 2
threelittlekeys #android #apk-reversing #seeded-prng	CyberSecurityRumble 2022	62.00	Reverse	files wu 1
Delegate-wallet #lcg-prng-prediction #weak-randomness	0x41414141 2021	–	Crypto	files wu 2
crypto-casino #predictable-on-chain-randomness #keccak-prng #weak-seed	0x41414141 2021	–	Crypto	files wu 1
Pseudo #legendre-prng #fermat-pseudoprime	BuckeyeCTF 2021	24.81	Crypto	files wu 1
Shrine_of_the_Sweating_Buddha #paillier-predictable-randomness	K3RN3LCTF 2021	24.37	Crypto	files wu 1
Shamirs_Stingy_Sharing #secret-sharing #polynomial-leak #prng-seed	RaRCTF 2021	24.53	Crypto	files wu 1
minigen #linear-recurrence #xor #prng	RaRCTF 2021	24.53	Crypto	files wu 3
FryingInMotion #prng-prediction	Dragon 2020	98.00	Crypto	files wu 1
SeedSpring #predictable-rng #srand	VirSecCon 2020	22.79	Misc	files wu 2
random_vault #format-string #srand-seed-overwrite #function-pointer-overwrite #shellcode	Pwn2Win 2019	43.00	Misc	files wu 3

Challenges