2024 Business CTF - Vault of Hope: Exciting Outpost Recon
Cryptography challenge using known plaintext attack to break XOR-based encryption with SHA-256 key derivation
2024 Cyber Apocalypse: Dynasty
Reverse a custom Caesar cipher variant with position-dependent shift
2024 Cyber Apocalypse: Blunt
Exploit weak Diffie-Hellman with small parameters to recover shared secret and decrypt AES-CBC ciphertext
2024 Cyber Apocalypse: Iced Tea
Identify TEA cipher from DELTA constant and decrypt ECB-mode ciphertext with known key
2024 Cyber Apocalypse: Permuted
Break Diffie-Hellman over permutation groups using DLP algorithm on permutation cycles
2024 Cyber Apocalypse: Makeshift
Reverse a trivial string transformation: reverse flag then rearrange groups of three
2024 Cyber Apocalypse: Primary Knowledge
Exploit RSA implementation using prime modulus instead of semiprime
HTB Hack The Boo Practice: Hexoding64
Decode a flag split between hex and base64 encoding
HTB Hack The Boo Practice: SPG
Reverse engineer a password generator to decrypt an encrypted flag
HTB Hack The Boo Practice: yesnce
Exploit AES-CTR mode with predictable counter and key recovery
2023 Business CTF: Initialization
Break AES-CTR encryption with nonce reuse vulnerability
2023 Business CTF: Interception
Exploit weak PRNG in RSA system to decrypt enemy communications
2023 Business CTF: Vitrium Stash
Forge DSA signatures to access vitalium resource coordinates
2023 Business CTF: I'm gRoot
Forge Merkle tree signatures to detect a blockchain backdoor
2023 Cyber Apocalypse: Small sTeps
Exploit RSA with small public exponent e=3 using Coppersmith's attack
2023 Cyber Apocalypse: Multipage Recyclings
Exploit custom AES ECB implementation with block recycling vulnerability
2023 Cyber Apocalypse: Perfect Synchronization
Exploit AES ECB mode encryption with known plaintext and partial key recovery
2023 Cyber Apocalypse: Ancient Encodings
Reverse engineer a multi-layer encoding scheme involving hex conversion and base64
2022 Hack The Boo: Gonna Lift Em All
Discrete log problem with extremely small prime - trivial brute force attack
2022 Hack The Boo: Whole Lotta Candy
AES encryption challenge with multiple block cipher modes - exploit ECB mode weakness