Challenge 2-1: Million Bounty Problem Description: An encrypted file contains experimental data. The encryption process involves two steps: Caesar cipher with an unknown shift (1–10, applied only to letters). Rail fence cipher with an unknown key (2–4), using a W-shaped (zigzag) reading pattern and...
Challenge Overview Source: BUUCTF Platform Objective: Retrieve the flag value. Approach The challenge presents a web page with minimal visible content. The URL contains a query parameter ?id=1, indicating this is a standard SQL injection vulnerability. Determining Injection Type First, test whether...
[CISCN 2021 Preliimnary] babybc This challenge provdies a 64-bit ELF binary obfuscated with LLVM control-flow flattening, distributed as a BC LLVM IR file. Reverse engineering reveals the core problem is a constrained 5x5 sudoku puzzle, with custom order constraints encoded in two matrices, which ca...