Biblio
To prevent unauthorized access to adversaries, strong authentication scheme is a vital security requirement in client-server inter-networking systems. These schemes must verify the legitimacy of such users in real-time environments and establish a dynamic session key fur subsequent communication. Of late, T. H. Chen and J. C. Huang proposed a two-factor authentication framework claiming that the scheme is secure against most of the existing attacks. However we have shown that Chen and Huang scheme have many critical weaknesses in real-time environments. The scheme is prone to man in the middle attack and information leakage attack. Furthermore, the scheme does not provide two essential security services such user anonymity and session key establishment. In this paper, we present an enhanced user participating authenticating scheme which overcomes all the weaknesses of Chen et al.'s scheme and provide most of the essential security features.
In this paper, we propose a novel visual secret sharing (VSS) scheme for color QR code (VSSCQR) with (n, n) threshold based on high capacity, admirable visual effects and popularity of color QR code. By splitting and encoding a secret image into QR codes and then fusing QR codes to generate color QR code shares, the scheme can share the secret among a certain number of participants. However, less than n participants cannot reveal any information about the secret. The embedding amount and position of the secret image bits generated by VSS are in the range of the error correction ability of the QR code. Each color share is readable, which can be decoded and thus may not come into notice. On one hand, the secret image can be reconstructed by first decomposing three QR codes from each color QR code share and then stacking the corresponding QR codes based on only human visual system without computational devices. On the other hand, by decomposing three QR codes from each color QR code share and then XORing the three QR codes respectively, we can reconstruct the secret image losslessly. The experiment results display the effect of our scheme.