SK-CERT CyberGame 2026: Cryptography Challenges Writeup
A full walkthrough of the SK-CERT CyberGame 2026 cryptography challenges, covering five distinct problems ranging from beginner to advanced. Topics include musical notation substitution ciphers, layered repeating-key XOR with PE reverse engineering, ZipCrypto known-plaintext attacks using bkcrack, an anomalous RSA challenge with an exponent approaching N^4 solved via lattice methods, and a quadratic twist elliptic curve DLP solved with Pohlig-Hellman over smooth-order subgroups. Each writeup includes full solution scripts, beginner-friendly explanations, and key takeaways on the underlying cryptographic weaknesses.
May 13, 2026