Cryptanalysis and improvement of chen-hsiang-shih's remote user authentication scheme using smart cards

Recently, Chen-Hsiang-Shih proposed a new dynamic ID-based remote user authentication scheme. The authors claimed that their scheme was more secure than previous works. However, this paper demonstrates that theirscheme is still unsecured against different kinds of attacks. In order to enhance the security of the scheme proposed by Chen-Hsiang-Shih, a new scheme is proposed. The scheme achieves the following security goals: without verification table, each user chooses and changes the password freely, each user keeps the password secret, mutual authentication, the scheme establishes a session key after successful authentication, and the scheme maintains the user's anonymity. Security analysis and comparison demonstrate that the proposed scheme is more secure than Das-Saxena-Gulati's scheme, Wang et al.'s scheme and Chen-Hsiang-Shih.Peer ReviewedPostprint (published version

Robust Smart Card based Password Authentication Scheme against Smart Card Security Breach

As the most prevailing two-factor authentication mechanism, smart card based password authentication has been a subject of intensive research in the past decade and hundreds of this type of schemes have been proposed. However, most of them were found severely flawed, especially prone to the smart card loss problem, shortly after they were first put forward, no matter the security is heuristically analyzed or formally proved. In SEC\u2712, Wang pointed out that, the main cause of this issue is attributed to the lack of an appropriate security model to fully identify the practical threats. To address the issue, Wang presented three kinds of security models, namely Type I, II and III, and further proposed four concrete schemes, only two of which, i.e. PSCAV and PSCAb, are claimed to be secure under the harshest model, i.e. Type III security model. However, in this paper, we demonstrate that PSCAV still cannot achieve the claimed security goals and is vulnerable to an offline password guessing attack and other attacks in the Type III security mode, while PSCAb has several practical pitfalls. As our main contribution, a robust scheme is presented to cope with the aforementioned defects and it is proven to be secure in the random oracle model. Moreover, the analysis demonstrates that our scheme meets all the proposed criteria and eliminates several hard security threats that are difficult to be tackled at the same time in previous scholarship