R4Y4N3

2026

SEKAI CTF 2026 — Blockchain Writeups

Complete writeups for every SEKAI CTF 2026 blockchain challenge: analysis, vulnerable code, exploits, root causes, and fixes.

R R4Y4N3
June 28, 2026
29 min read

blockchain ctf solidity write-up

2025

Inside the Chain: Designing Blockchain Challenges for Nextrace CTF

The design and solutions behind four Web3 challenges covering key management, chain analysis, IPFS, and hidden contract functions.

R R4Y4N3
November 6, 2025
4 min read

blockchain ctf challenge-design write-up