HOW TO: Implement CAPTCHA with ASP.NET

CAPTCHA stands for Completely Automated Public Turing Test to Tell Computers and Humans Apart.

Solution

• CAPTCHA Image by BrainJar (CodeProject.com)
• Fighting Spambots with .NET and AI by Adnan Masood (15Seconds.com) - also demonstrates how to deliver and invoke CAPTCHA from a web service.

Related Resources

• MSDN: System.Drawing Namespace
• The CAPTCHA Project
• Baffling the Bots by Lee Bruno (Scientific American.com)
• Robot solves Internet robot problem by Byron Spice (Post-Gazette)
• Protect Your Online Forms by John Clyman (PC Magazine)
• CAPTCHA-ing the Spammer by Cade Metz (PC Magazine)