Abstract: Quick response codes or QR codes are increasing their popularity as they appear in more places in the todayís scenario. Quick Response Codes can be considered as physical hyperlinks that give the ability to users to access information, share messages and authenticate the documents. Apart from marketing, QR Codes have been also adopted in different areas such as the on-line payments. As the usage of QR codes is increasing day by day care must be taken while designing the QR code so that there arenít any issues regarding its security and privacy. In this paper we have studied various state of the art existing techniques of designing QR code along with their comparison with each other. Also various state of the art existing techniques of document authentication with their comparison with each other.

Keywords: QR Code, Image Processing, Feature Extraction, Digital Signature.