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Comprehensive collection of CTF challenges, solutions, and insights.


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Raptor Weekly 2 - ECHELON Rev 1 - 4.1 ; REMNANT

Reversing a stripped x86-64 ELF to recover Diffie-Hellman parameters with a smooth group order, applying Pohlig-Hellman to recover the private key, and decrypting a C2 beacon payload to extract a handshake key and the flag. Or just running the binary.

DEADROP Crypto 6 - CIPHER7

Fourstage cryptographic chain, repair a corrupted Reed-Solomon encoded key file, solve the discrete logarithm problem on a backdoored elliptic curve with smooth group order via Pohlig-Hellman, locate a hidden nonce in a binary header, derive the AES key, and decrypt the final briefing.