New Fool Proof Examination System through Color Visual Cryptography and Signature Authentication

There have been widespread allegations about the question papers leakage for a number of subjects in the recently held Secondary School Leaving Certificate examinations. The leakage is due to the practice of using printed question papers. Such incidents and subsequent cancellation of examinations are happening frequently. This creates political and social embarrassment and causes loss of money and time. This paper proposes a new system of foolproof examination by tamperproof e-question paper preparation and secure transmission using secret sharing scheme. The application is perfectly secure because the proposed method automatically embeds the corresponding institute seal in the form of the key. As a result, it is easy to trace out the source culprit for the leakage of question papers. This scheme has reduced reconstruction time because the reconstruction process involves only Exclusive-OR (XOR) operation apart from authentication. The proposed method recovers the original secret image without any loss. The existing visual cryptographic scheme recovers half-toned secret image with average Peak Signal-to-Noise Ratio (PSNR) value 24dB. Further, it shall be stated that the proposed method with authentication recovers the image with 64.7dB PSNR value, which is greater than that of the existing method. In addition, this method does not suffer from pixel Expansion.