All Writeups

Comprehensive collection of CTF challenges, solutions, and insights.

2026-05-10 Forensics Hard

Raptor Weekly 2 - ECHELON Forensics 1 - 3.3 ; COLD CASE

Parsing a proprietary ECHELON memory snapshot format, deriving an AES-128-CBC decryption key from an operator certificate recovered in the prior challenge, and extracting a file access record from a process heap to reconstruct the TOP SECRET portal password.

forensics memory aes-cbc ECHELON

2026-05-10 Network Hard

Raptor Weekly 2 - ECHELON Network 2 - 4.2 ; EXFIL

Parsing a custom ECP/1.2 protocol capture, deriving a stream key via HMAC-SHA256 from the Tier 4 handshake key, decrypting three of four signing key chunks, and hunting down the missing chunk in a PCAP from two tiers and two days earlier.

network crypto pcap aes-cbc

2026-03-01 Crypto Insane

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.

reed-solomon elliptic-curve pohlig-hellman ecdlp