In network and application security since mid-90's. Done quite a lot of different things, starting from low-level penetration testing, embedded devices design, EU electronic signature consulting and large scale application security management. Active member of OWASP. Author of WebCookies.info and CSPBuilder.info. Writing at two blogs: IPSec.pl (English/Polish) and Echelon.pl (Polish only).
Q&A for professional and enthusiast programmers
Q&A for Information security professionals
Q&A for pro webmasters
Q&A for software developers, mathematicians and others interested in cryptography