CTF challenges & writeups

1454 challenges in family ⊕ crypto ✕ clear · browse all techniques

Challenge	CTF	Weight	Category	Has
vault-door-6 #xor	picoCTF 2019	–	Reverse	files wu 1
vault-door-8 #bit-transposition	picoCTF 2019	–	Reverse	files wu 1
Voting_Machine_1 #polynomial	watevrCTF 2019	24.92	Misc	files wu 3
FederationWorkflowSystem #aes-ecb #byte-at-a-time-decryption #chosen-prefix	CTFZone 2018 Quals	23.92	Misc	files wu 1
SignatureServer #winternitz-ots #signature-forgery #checksum-bypass	CTFZone 2018 Quals	23.92	Misc	files wu 1
lucky #prng-seed-overwrite #rand-prediction #buffer-overflow	Defcamp 2018 Quals	18.75	Misc	files wu 3
secretnote #coppersmith	HITCON 2018	–	Misc	files wu 1
forbidden #aes-gcm #forbidden-attack #nonce-reuse	VolgaCTF 2018 Quals	25.12	Misc	files wu 3
Back_to_Base-ics #encoding #base64	angstromCTF 2018	–	Crypto	files wu 1
Intro_to_RSA #rsa	angstromCTF 2018	–	Crypto	files wu 1
Rev3 #xor	angstromCTF 2018	–	Reverse	files wu 1
Warmup #affine-cipher	angstromCTF 2018	–	Crypto	files wu 1
XOR #single-byte-xor	angstromCTF 2018	–	Crypto	files wu 1
ofb #ofb #known-plaintext	angstromCTF 2018	–	Crypto	files wu 1
Almost Xor #xor #known-plaintext	CSAW 2017 Quals	24.61	Crypto	files src wu 1
Baby Crypt #aes-ecb #chosen-plaintext #byte-at-a-time	CSAW 2017 Quals	24.61	Crypto	files src wu 1
SSSP #subset-sum #mt19937	HITCON 2017 Quals	69.38	Crypto	files src wu 1
Artifact #substitution-cipher #quipqiup	angstromCTF 2016	–	Crypto	files src wu 1
SPQR #caesar-cipher	angstromCTF 2016	–	Crypto	files src wu 1
What the Hex #hex #base64	angstromCTF 2016	–	Crypto	files src wu 1
Random Image #image-encoding #prng	ASIS 2014 Quals	–	Crypto	files wu 1
Boring_APK #android-native-reversing #meet-in-the-middle (mitm)	BKISC 2026	–	Reverse	files wu 1
NACREVAULT #lattice #ring-lwe #ternary-secret #ring-projection	COMPFEST 2026	–	Crypto	files wu 1
The_67th_Line #osint #baconian-cipher	COMPFEST 2026	–	Crypto	files wu 1
Chimera_Vault #merkle-hellman #knapsack #key-reuse	CSS 2026	–	Crypto	files wu 1
Chrono_I #vigenere #periodic-caesar	CSS 2026	–	Crypto	files wu 1
Lamp_Drill #logic-gates	CSS 2026	–	Hardware	files wu 1
Severed_Symmetry #multivariate-cryptography #oil-and-vinegar	CSS 2026	–	Crypto	files wu 1
Phantom_Mesh #power-analysis #side-channel #cpa #aes	Cryovault 2026 Quals	25.00	Forensics	files wu 1
near_miss #fuzzy-match-oracle #oracle-attack	Cryovault 2026 Quals	25.00	Web	files wu 1
one_more #schnorr-signature #ros-attack #signature-forgery	Cryovault 2026 Quals	25.00	Crypto	files wu 1
Handprint #sudo-io-log #zlib #terminal-forensics	Haruulzangi 2026 Quals	–	Forensics	files wu 1
Likeness #unicode-normalization #nfkc #auth-bypass	Haruulzangi 2026 Quals	–	Web	files wu 1
Sur_Kharvaa #pyjail #utf-7 #parser-differential	Haruulzangi 2026 Quals	–	Misc	files wu 1
Crossword_1 #codeword-puzzle #substitution-cipher #ocr	KBxAc 2026	–	Crypto	files wu 1
Crossword_2 #codeword-puzzle #substitution-cipher	KBxAc 2026	–	Crypto	files wu 1
Dead_Validator #ecdsa #nonce-reuse	KBxAc 2026	–	Crypto	files wu 1
Game_of_Life #binary-encoding #tile-decoding	KBxAc 2026	–	Misc	files wu 1
Ghost_in_the_Group #diffie-hellman #pohlig-hellman #smooth-order	KBxAc 2026	–	Crypto	files wu 1
Icarus_Enclave #base65536 #rsa-crt-fault #hkdf #aes-gcm #hash-length-extension	KBxAc 2026	–	Crypto	files wu 1

Challenges