Abstract

Biometric based authentication protocols for multi-server architectures have gained momentum in recent times due to advancements in wireless technologies and associated constraints. Lu et al. recently proposed a robust biometric based authentication with key agreement protocol for a multi-server environment using smart cards. They claimed that their protocol is efficient and resistant to prominent security attacks. The careful investigation of this paper proves that Lu et al.’s protocol does not provide user anonymity, perfect forward secrecy and is susceptible to server and user impersonation attacks, man-in-middle attacks and clock synchronization problems. In addition, this paper proposes an enhanced biometric based authentication with key-agreement protocol for multi-server architecture based on elliptic curve cryptography using smartcards. We proved that the proposed protocol achieves mutual authentication using Burrows-Abadi-Needham (BAN) logic. The formal security of the proposed protocol is verified using the AVISPA (Automated Validation of Internet Security Protocols and Applications) tool to show that our protocol can withstand active and passive attacks. The formal and informal security analyses and performance analysis demonstrates that the proposed protocol is robust and efficient compared to Lu et al.’s protocol and existing similar protocols.

Abstract

A two-factor authenticated key-agreement scheme for session initiation protocol emerged as a best remedy to overcome the ascribed limitations of the password-based authentication scheme. Recently, Lu et al. proposed an anonymous two-factor authenticated key-agreement scheme for SIP using elliptic curve cryptography. They claimed that their scheme is secure against attacks and achieves user anonymity. Conversely, this paper's keen analysis points out several severe security weaknesses of the Lu et al.'s scheme. In addition, this paper puts forward an enhanced anonymous two-factor mutual authenticated key-agreement scheme for session initiation protocol using elliptic curve cryptography. The security analysis and performance analysis sections demonstrates that the proposed scheme is more robust and efficient than Lu et al.'s scheme.

Abstract

Widespread use of wireless networks has drawn attention to ascertain confidential communication and proper authentication of an entity before granting access to services over insecure channels. Recently, Truong et al. proposed a modified dynamic ID-based authentication scheme which they claimed to resist smart-card-theft attack. Nevertheless, we find that their scheme is prone to smart-card-theft attack contrary to the author’s claim. Besides, anyone can impersonate the user as well as service provider server and can breach the confidentiality of communication by merely eavesdropping the login request and server’s reply message from the network. We also notice that the scheme does not impart user anonymity and forward secrecy. Therefore, we present another authentication scheme keeping apart the threats encountered in the design of Truong et al.’s scheme. We also prove the security of the proposed scheme with the help of widespread BAN (Burrows, Abadi and Needham) Logic.

Abstract

Spread of wireless network technology has opened new doors to utilize sensor technology in various areas via Wireless Sensor Networks (WSNs). Many authentication protocols for among the service seeker users, sensing component sensor nodes (SNs) and the service provider base-station or gateway node (GWN) are available to realize services from WSNs efficiently and without any fear of deceit. Recently, Li et al. and He et al. independently proposed mutual authentication and key agreement schemes for WSNs. We find that both the schemes achieve mutual authentication, establish session key and resist many known attacks but still have security weaknesses. We show the applicability of stolen verifier, user impersonation, password guessing and smart card loss attacks on Li et al.’s scheme. Although their scheme employs the feature of dynamic identity, an attacker can reveal and guess the identity of a registered user. We demonstrate the susceptibility of He et al.’s scheme to password guessing attack. In both the schemes, the security of the session key established between user and SNs is imperfect due to lack of forward secrecy and session-specific temporary information leakage attack. In addition both the schemes impose extra computational load on resource scanty sensor-nodes and are not user friendly due to absence of user anonymity and lack of password change facility. To handle these drawbacks, we design a mutual authentication and key agreement scheme for WSN using chaotic maps. To the best of our knowledge, we are the first to propose an authentication scheme for WSN based on chaotic maps. We show the superiority of the proposed scheme over its predecessor schemes by means of detailed security analysis and comparative evaluation. We also formally analyze our scheme using BAN logic.

Abstract

Molecular level understanding of mutational effects on stability and activity of enzymes is challenging particularly when several point mutations are incorporated during the directed evolution experiments. In our earlier study, we have suggested the lack of consistency in the effect of point mutations incorporated during the initial generations of directed evolution experiments, towards conformational stabilization of B. subtilis lipase mutants of later generations. Here, we report that the cumulative point mutations incorporated in mutants 2M (with two point mutations) to 6M (with six point mutations) possibly do not retain their original stabilizing nature in the most thermostable 12M mutant (with 12 point mutations). We have carried out MD simulations using structures incorporating reversal of different sets of point mutations to assess their effect on the conformational stability and activity of 12M. Our analysis has …

Abstract

Background and objectives: Mutual authentication is a very important service that must be established between sensor nodes in wireless body area network (WBAN) to ensure the originality and integrity of the patient’s data sent by sensors distributed on different parts of the body. However, mutual authentication service is not enough. An adversary can benefit from monitoring the traffic and knowing which sensor is in transmission of patient’s data. Observing the traffic (even without disclosing the context) and knowing its origin, it can reveal to the adversary information about the patient’s medical conditions. Therefore, anonymity of the communicating sensors is an important service as well. Few works have been conducted in the area of mutual authentication among sensor nodes in WBAN. However, none of them has considered anonymity among body sensor nodes. Up to our knowledge, our protocol is the first attempt to consider this service in a two-tier WBAN. We propose a new secure protocol to realize anonymous mutual authentication and confidential transmission for star two-tier WBAN topology. Methods: The proposed protocol uses simple cryptographic primitives. We prove the security of the proposed protocol using the widely-accepted Burrows-Abadi-Needham (BAN) logic, and also through rigorous informal security analysis. In addition, to demonstrate the practicality of our protocol, we evaluate it using NS-2 simulator. Results: BAN logic and informal security analysis prove that our proposed protocol achieves the necessary security requirements and goals of an authentication service. The simulation results show the impact on the various network parameters, such as end-to-end delay and throughput. The nodes in the network require to store few hundred bits. Nodes require to perform very few hash invocations, which are computationally very efficient. The communication cost of the proposed protocol is few hundred bits in one round of communication. Due to the low computation cost, the energy consumed by the nodes is also low.

Abstract

In the last decade, discovery of copy number variations (CNVs) have dramatically changed our understanding of differences between individuals. CNVs include both additional copies of sequence (duplications) and loss of genetic material (deletions) and provide an alternate paradigm for the genetic basis of human diseases. Genome-wide CNV detection is now possible using high-throughput, low-cost next generation sequencing (NGS) methods. Nature of NGS data demands various preprocessing and pretreatment steps before extracting any meaningful information. Among the plethora of variant calling methods available, R-based methods offer flexible environment, facilitating choice of various methods depending on the type of data or type of analysis to be performed. Here we give a pipeline for various steps involved in CNV detection in NGS data using R-based algorithms and packages.

Abstract

Traditionally, protein structures have been analysed by the secondary structure architecture and fold arrangement. An alternative approach that has shown promise is modelling proteins as a network of non-covalent interactions between amino acid residues. The network representation of proteins provide a systems approach to topological analysis of complex three-dimensional structures irrespective of secondary structure and fold type and provide insights into structure-function relationship. We have developed a web server for network based analysis of protein structures, NAPS, that facilitates quantitative and qualitative (visual) analysis of residue–residue interactions in: single chains, protein complex, modelled protein structures and trajectories (e.g. from molecular dynamics simulations). The user can specify atom type for network construction, distance range (in Å) and minimal amino acid separation along the

Abstract

Background and objectives Information and communication and technology (ICT) has changed the entire paradigm of society. ICT facilitates people to use medical services over the Internet, thereby reducing the travel cost, hospitalization cost and time to a greater extent. Recent advancements in Telecare Medicine Information System (TMIS) facilitate users/patients to access medical services over the Internet by gaining health monitoring facilities at home. Methods Amin and Biswas recently proposed a RSA-based user authentication and session key agreement protocol usable for TMIS, which is an improvement over Giri et al.'s RSA-based user authentication scheme for TMIS. In this paper, we show that though Amin–Biswas's scheme considerably improves the security drawbacks of Giri et al.'s scheme, their scheme has security weaknesses as it suffers from attacks such as privileged insider attack, user impersonation attack, replay attack and also offline password guessing attack. A new RSA-based user authentication scheme for TMIS is proposed, which overcomes the security pitfalls of Amin–Biswas's scheme and also preserves user anonymity property. Results The careful formal security analysis using the two widely accepted Burrows–Abadi–Needham (BAN) logic and the random oracle models is done. Moreover, the informal security analysis of the scheme is also done. These security analyses show the robustness of our new scheme against the various known attacks as well as attacks found in Amin–Biswas's scheme. The simulation of the proposed scheme using the widely accepted Automated Validation of Internet Security Protocols and Applications (AVISPA) tool is also done. Conclusions We present a new user authentication and session key agreement scheme for TMIS, which fixes the mentioned security pitfalls found in Amin–Biswas's scheme, and we also show that the proposed scheme provides better security than other existing schemes through the rigorous security analysis and verification tool. Furthermore, we present the formal security verification of our scheme using the widely accepted AVISPA tool. High security and extra functionality features allow our proposed scheme to be applicable for telecare medicine information systems which is used for e-health care medical applications.

Abstract

Mobile Healthcare (mHealth) continues to improve because of significant improvements and the decreasing costs of Information Communication Technologies (ICTs). mHealth is a medical and public health practice, which is supported by mobile devices (for example, smartphones) and, patient monitoring devices (for example, various types of wearable sensors, etc.). An mHealth system enables healthcare experts and professionals to have ubiquitous access to a patient’s health data along with providing any ongoing medical treatment at any time, any place, and from any device. It also helps the patient requiring continuous medical monitoring to stay in touch with the appropriate medical staff and healthcare experts remotely. Thus, mHealth has become a major driving force in improving the health of citizens today. First, we discuss the security requirements, issues and threats to the mHealth system. We then present a taxonomy of recently proposed security protocols for mHealth system based on features supported and possible attacks, computation cost and communication cost. Our detailed taxonomy demonstrates the strength and weaknesses of recently proposed security protocols for the mHealth system. Finally, we identify some of the challenges in the area of security protocols for mHealth systems that still need to be addressed in the future to enable cost-effective, secure and robust mHealth systems.