An Effective Authentication Scheme Using DCT for Mobile Devices

Abstract

This paper proposes an image authentication scheme for mobile devices. The proposed scheme generates an image watermark by using discrete cosine transform (DCT) and hides the watermark in the spatial pixels for image authentication and tamper detection. The hiding operator used in this paper is very simple in a mobile environment allowing high-speed authentication using a low-power mobile device. The quality of the stego-image and the recovered image becomes excellent as a result of the proposed scheme.

Analysis of Embedding Locations in the Subband Frequency DCT on Scanned Images

“…The conditions that must be met by an original image in the watermark embedding process using Discrete Cosine Transform (DCT) are stated in Equation (1).…”

“…High ((0,7), (1,6), (2,5), (3,4),(4,3),(5,2),(6,1),(7,0),(7,1),(6,2),(5,3),(4,4), (3,5), (2,6), (1,7),(2,7), (3,6), (4,5), (5,4),(6,3),(7,2), (7,3), (6,4), (5,5), (4,6), (3,7),(4,7), (5,6), (6,5), (7,4), (7,5), (6,6), (5,7),(6,7), (7,6),(7,7))…”

“…Many techniques have been proposed to protect images, such as cryptography, watermarking, digital signatures, and so on [1]. In this study, the proposed technique is watermarking.…”

High-Precision Authentication Scheme Based on Matrix Encoding for AMBTC-Compressed Images

“…However, some of them could not withstand a vector quantization attack [9] or the tampering coincidence problem [10]. To overcome those problems, other fragile watermarking strategy-based block mappings were proposed by [11][12][13][14][15][16]. In these schemes, the original image is divided into non-overlapping blocks and the authentication code is generated by employing different kinds of technologies for each block, including the discrete cosine transform (DCT)-based method [11,12], the singular value decomposition (SVD)-based method [13,14], and the coding-based method [15,16].…”

“…Verification is conducted by comparing the extracted and recalculated authentication code. These schemes [11][12][13][14][15] also adopt a multi-hierarchical tampering detection strategy to improve the tampering detection rate; for example, a first hierarchical tampering detection strategy is used to initially identify the tampered area and a second hierarchical tampering detection strategy serves as a remediation measure. As a consequence, these approaches have high precision in tampering detection.…”