A novel verification code technology based on image hiding

Verification code technology is designed to distinguish humans from computers using distorted letters and/or numbers, to protect websites from automatic attacking. The current verification code technology faces the dilemma of complexity design: too simple for an attacking machine to recognize automatically, or too complex for a human user. This paper proposes a novel scheme based on image hiding. The verification codes are embedded into a background image so that the code is hardly recognized by machines, but it is easy for users by a simple operation. Theoretical analysis and simulation experiments illustrate that this scheme is effective, safe and with low complexity.