The article "XCTF-getit我差点就信了！详解CTF逆向中那个“无效”的置换算法" delves into a Capture The Flag (CTF) challenge on the XCTF platform, focusing on a substitution algorithm that initially appears ineffective but is actually complex. The challenge, named "getit," is designed to test participants' reverse engineering skills by requiring them to analyze and decrypt the algorithm. The article provides a detailed explanation of the substitution algorithm and the steps necessary to decrypt it, highlighting the complexity and the need for careful analysis. While the immediate impact of this challenge is confined to the CTF context, the skills and techniques discussed are broadly applicable in cybersecurity. Reverse engineering and cryptanalysis are critical skills for cybersecurity professionals, and understanding complex substitution algorithms can aid in breaking encryption schemes and analyzing malware. The article serves as a valuable resource for professionals looking to enhance their reverse engineering skills and offers practical insights into the analysis of substitution algorithms. For cybersecurity experts, engaging in such challenges and studying cryptography can significantly improve their ability to tackle real-world security issues.