YoungJin is a co-founder of Wellbia.com Co., Ltd., a security company in South Korea, and Visual C++ Microsoft Most Valuable Professional. He has developed anti-cheat program called XIGNCODE since 2007. He wrote several PC security programs like PC Firewall, Anti-Spyware, and Keyboard Security Software. He has contributed a number of articles about Windows programming to Microsoftware, the famous programming magazine of South Korea. He also hosts a blog (http://www.jiniya.net) that includes articles about system programming on Windows.