CTF challenges & writeups

873 challenges in family ⊕ crypto ✕ clear · browse all techniques

Challenge	CTF	Weight	Category	Has
concord #finite-field #brute-force	VuwCTF 2026	25.00	Crypto	files wu 1
dotsbedashing #morse-code #xor #bit-rotation	VuwCTF 2026	25.00	Reverse	files wu 1
ilikewords #xor #kaprekar-constant	VuwCTF 2026	25.00	Reverse	files wu 1
nom_nom #rsa #franklin-reiter #related-message	VuwCTF 2026	25.00	Crypto	files wu 1
Escatlate_flag_2 #unicode-case-mapping-bypass #touppercase-tolowercase-normalization	1753CTF 2025	34.82	Web	files wu 1
Minesweeper_2 #linear-system-solving	BITSCTF 2025	–	Crypto	files wu 1
Noob_RSA_Returns #rsa #fermat-little-theorem	BITSCTF 2025	–	Crypto	files wu 1
RSA_Bummer #wilsons-theorem #rabin-cryptosystem	BITSCTF 2025	–	Crypto	files wu 1
Bakerman #file-signature-spoofing #zsteg	BrunnerCTF 2025	24.66	Misc	files wu 1
portable_graphics #go-binary-reversing #png-chunk-crafting #custom-chunk	CTF@AC 2025 Quals	24.53	Reverse	files wu 1
Poor_Megan #cyberchef-magic #encoding	DEADFACE 2025	–	Crypto	files wu 3
Clockwork #xor	EnigmaXplore 2025	–	Reverse	files wu 1
restricted_oracle #padding-oracle	GPN 2025	–	Crypto	files wu 2
Baby_Sharingan #known-plaintext	H7CTF 2025	22.56	Crypto	files wu 1
Crispy_Kelp #xor-cipher	IrisCTF 2025	34.30	Reverse	files wu 1
Let_s_Break_Something_at_LoWE_s #lwe	JerseyCTF 2025	24.73	Crypto	files wu 1
MMDLX #multi-layer-base64	Kashi 2025	21.78	Crypto	files wu 1
Random_Inator #predictable-prng-key	Kashi 2025	21.78	Crypto	files wu 1
Knights_Droid #caesar-cipher	KnightCTF 2025	18.78	Reverse	files wu 1
RandomseniorAdleman #prng-seed-rsa	KnightCTF 2025	18.78	Crypto	files wu 1
Certay #php-signature-forgery	L3akCTF 2025	24.43	Web	files wu 1
Flag_L3ak #search-filter-oracle	L3akCTF 2025	24.43	Web	files wu 1
Lowkey_RSA #wiener-attack	L3akCTF 2025	24.43	Crypto	files wu 2
Magical_Oracle #hidden-number-problem	L3akCTF 2025	24.43	Crypto	files wu 1
Mersenne_Mayhem #continued-fractions	L3akCTF 2025	24.43	Crypto	files wu 1
McFlagChecker #matrix-inversion-reversing	LA 2025	–	Reverse	files wu 1
Key_Exchange #diffie-hellman-key-exchange	N0PSctf 2025	24.34	Crypto	files wu 1
Cryptoclock #known-plaintext-xor	NahamCon 2025	53.77	Crypto	files wu 1
Last_Flight #isogeny #supersingular-elliptic-curve	SECCON 2025 Quals	–	Crypto	files wu 1
Alter_Ego #csidh #isogeny	SekaiCTF 2025	55.00	Crypto	files src wu 1
Gondola #reversing #webassembly #z3	SekaiCTF 2025	55.00	Reverse	files wu 1
Numbers_Game #prng-prediction #rand-seed	SunshineCTF 2025	51.65	Reverse	files wu 1
OK_BOOMER #t9-multitap-encoding	SunshineCTF 2025	51.65	Misc	files wu 1
Palatine_Pack #reversing #xor	SunshineCTF 2025	51.65	Reverse	files wu 1
Contamination #proxy-bypass #parser-differential	SwampCTF 2025	40.40	Web	files wu 1
Rock_my_Password #password-cracking #rockyou	SwampCTF 2025	40.40	Crypto	files wu 2
encrypted_chat #many-time-pad #keystream-reuse #race-condition	TPCTF 2025	–	Crypto	files wu 1
verified_toolbox #cve-2024-38807 #jar-signature-forgery	TPCTF 2025	–	Misc	files wu 1
symmetric #rsa #multi-prime	UIUCTF 2025	–	Crypto	files wu 1
too_many_primes #rsa #multi-prime	UIUCTF 2025	–	Crypto	files wu 1

Challenges