Crypto CTF challenges

4,483 Crypto CTF challenges from 404 CTFs (2011–2026), 708 with writeups.

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Challenges

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Challenge	CTF	Weight	Has
HADIOR #hamming-distance-oracle	K3RN3LCTF 2021	24.37	files wu 1
1+1_3 #groth16-proof-forgery	L3akCTF 2026	34.47	files wu 1
cryptoGRAPHy_1 #graph-encryption #token-decryption	SekaiCTF 2023	24.86	files wu 1
cryptoGRAPHy_3 #graph-encryption #query-recovery #leakage-abuse	SekaiCTF 2023	24.86	files wu 1
cryptoGRAPHy_2 #graph-encryption #leakage-abuse #shortest-path-tree	SekaiCTF 2023	24.86	files wu 1
Mr-Worldwide #gps-coordinates #geolocation	picoCTF 2019	–	files wu 1
Giffy #gif-frame-extraction #steganography	Damncon 2022	17.54	files wu 1
Beecryption #gf2-linearization	K3RN3LCTF 2021	24.37	files wu 1
garbled #garbled-circuits #meet-in-the-middle (mitm)	DiceCTF 2021	24.82	files wu 1
Total_Encryption #franklin-reiter	K3RN3LCTF 2021	24.37	files wu 1
concord #finite-field #brute-force	VuwCTF 2026	25.00	files wu 1
TallestHeader #file-signature-repair #transposition-cipher #binwalk	VishwaCTF 2022	20.79	files wu 1
EmailIncoming #file-signature #archive-cracking #steganography	VishwaCTF 2023	22.69	files wu 1
breakfaest #fiat-shamir-forgery	KalmarCTF 2024	24.21	files wu 1
superbox #feistel-cipher #algebraic-cryptanalysis	corCTF 2023	36.97	files wu 1
Obscurity-fixed #fcsr	m0leCon 2021 Quals	24.55	files wu 1
Key_in_a_Haystack #factorization #small-primes	UIUCTF 2024	–	files wu 1
the_receiver_of_many #encoding-decoding #book-cipher	SpringForwardCTF 2024	22.40	files wu 1
LockedOut #encoding-chain	Engineer 2022	22.65	files wu 1
Baby_Encoder #encoding #xor	TMUCTF 2021	–	files wu 1
CCCCC #encoding #nibble-swap	TFC 2024	–	files wu 1
Decode #encoding #hex-to-ascii #multi-layer-encoding	DaVinciCTF 2021	24.50	files wu 1
algebra #elliptic-curve-recovery	TetCTF 2022	36.72	files wu 1
Curvy_Curves #elliptic-curve-over-ring #rsa-factoring	BackdoorCTF 2023	–	files wu 1
Hextrap #ecm-factorization #rsa #oaep	V1T 2026	22.14	files wu 1
f_cktoring #ecm-factoring	hxp 2021	99.41	files wu 1
Signed_Jeopardy #ecdsa-nonce-reuse	NahamCon 2023	34.82	files wu 1
curved-mvm #ecdsa #weak-nonce #nonce-bruteforce #signature-forgery	x3ctf 2025	–	files wu 1
CwyptographicOwacle #ecdsa #signature-oracle #private-key-recovery #aes	DaVinciCTF 2022	24.50	files wu 1
yaonet #ecdsa #partial-key-exposure #bsgs #discrete-log #nist-p256	DiceCTF 2024 Quals	54.40	files wu 1
LCG_k #ecdsa #lcg-nonce #signature-forgery	corCTF 2021	24.92	files src wu 1
Vending_Machine #ecdsa #biased-nonce #signature-malleability #python-hash-collision #lattice	PwnMe 2025 Quals	24.95	files wu 1
Sign_Wars #ecdsa #biased-nonce #lattice #mt19937	SECCON 2021	–	files wu 1
mutant_mayhem #ecdsa	JerseyCTF 2024	21.26	files wu 1
Tick_Tock #ecdlp	K3RN3LCTF 2021	24.37	files wu 1
Elliptigo #ecc #small-subgroup-attack	BuckeyeCTF 2021	24.81	files wu 1
Clever_Thinking #ecc #ecdlp #discrete-log	UofTCTF 2024	23.90	files wu 1
QR_Codebook #ecb #known-plaintext	VolgaCTF 2021 Quals	32.73	files wu 1
Objection #dsa-malicious-generator	K3RN3LCTF 2021	24.37	files wu 1
Signed_Flag #dsa #signature	TMUCTF 2021	–	files wu 1