Certain Investigation on Captcha Design Based on Splitting, Rotating and Grid's Usage in the Images Against OCR
Network security consists of the provisions and policies adopted by a network administrator. Network security prevents and monitors unauthorized access, misuse, modification, or denial of a computer network and network accessible resources. A CAPTCHA is a program that generates and grades tests that are human solvable, but beyond the capabilities of current computer programs. This technology is now almost a standard security mechanism for addressing undesirable or malicious Internet bot programs and has found widespread application on numerous commercial web sites including Google, Yahoo, and Microsoft's MSN. It is widely accepted that a good CAPTCHA must be both robust and usable.