Abstract

Structural bioinformatics of RNA has evolved mainly in response to the rapidly accumulating evidence that non-(protein)-coding RNAs (ncRNAs) play critical roles in gene regulation and development. The structures and functions of most ncRNAs are however still unknown. Most of the available RNA structural databases rely heavily on known 3D structures, and contextually correlate base pairing geometry with actual 3D RNA structures. None of the databases provide any direct information about stabilization energies. However, the intrinsic interaction energies of constituent base pairs can provide significant insights into their roles in the overall dynamics of RNA motifs and structures. Quantum mechanical (QM) computations provide the only approach toward their accurate quantification and characterization. ‘RNA Base Pair Count, Geometry and Stability’ ( http://bioinf.iiit.ac.in/RNABPCOGEST …

Abstract

Traditional association rule mining based on the support–confidence framework provides the objective measure of the rules that are of interest to users. However, it does not reflect the semantic measure among the items. The semantic measure of an itemset is characterized with utility values that are typically associated with transaction items, where a user will be interested to an itemset only if it satisfies a given utility constraint. In this paper, we first define the problem of finding association rules using utility-confidence framework, which is a generalization of the amount-confidence measure. Using this semantic concept of rules, we then propose a compressed representation for association rules having minimal antecedent and maximal consequent. This representation is generated with the help of high utility closed itemsets (HUCI) and their generators. We propose the algorithms to generate the utility based non-redundant association rules and methods for reconstructing all association rules. Furthermore, we describe the algorithms which generate high utility itemsets (HUI) and high utility closed itemsets with their generators. These proposed algorithms are implemented using both synthetic and real datasets. The results demonstrate better efficiency and effectiveness of the proposed HUCI-Miner algorithm compared to other well-known existing algorithms. In addition, the experimental results show better quality in the compressed representation of the entire rule set under the considered framework.

Abstract

Recently, in 2014, He and Wang proposed a robust and efficient multi-server authentication scheme using biometrics-based smart card and elliptic curve cryptography (ECC). In this paper, we first analyze He-Wang's scheme and show that their scheme is vulnerable to a known session-specific temporary information attack and impersonation attack. In addition, we show that their scheme does not provide strong user's anonymity. Furthermore, He-Wang's scheme cannot provide the user revocation facility when the smart card is lost/stolen or user's authentication parameter is revealed. Apart from these, He-Wang's scheme has some design flaws, such as wrong password login and its consequences, and wrong password update during password change phase. We then propose a new secure multi-server authentication protocol using biometric-based smart card and ECC with more security functionalities. Using the Burrows-Abadi-Needham logic, we show that our scheme provides secure authentication. In addition, we simulate our scheme for the formal security verification using the widely accepted and used automated validation of Internet security protocols and applications tool, and show that our scheme is secure against passive and active attacks. Our scheme provides high security along with low communication cost, computational cost, and variety of security features. As a result, our scheme is very suitable for battery-limited mobile devices as compared with He-Wang's scheme.

Abstract

In recent years, Voice over Internet Protocol (VoIP) has gained more and more popularity as an application of the Internet technology. For various IP applications including VoIP, the topic of Session Initiation Protocol (SIP) has attracted major concern from researchers. SIP is an advanced signaling protocol operating on Internet Telephony. SIP uses digest authentication protocols such as Simple Mail Transport Protocol (SMTP) and HyperText Transport Protocol (HTTP). When a user seeks SIP services, authentication plays an important role in providing secure access to the server only to the authorized access seekers. Being an insecure-channel-based protocol, a SIP authentication protocol is susceptible to adversarial threats. Therefore, security is a big concern in SIP authentication mechanisms. This paper reveals the security vulnerabilities of two recently proposed SIP authentication schemes for VoIP, Irshad et al.’s scheme [Multimed. Tools. Appl. doi:10.1007/s11042-013- 1807-z] and Arshad and Nikooghadam’s scheme [Multimed. Tools. Appl. DOI 10.1007/ s11042-014-2282-x], the later scheme is based on the former scheme. Irshad et al.’s scheme suffers from password guessing, user impersonation and server spoofing attacks. Arshad and Nikooghadam’s scheme can be threatened with server spoofing and stolen verifier attack. None of these two schemes achieve mutual authentication. It also fails to follow the single round-trip authentication design of Irshad et al.’s scheme. To overcome these weaknesses, we propose a provable secure single round-trip SIP authentication scheme for VoIP using smart card. We formally prove the security of the scheme in random oracle and demonstrate through discussion its resistance to various attacks. The comparative analysis shows that the proposed SIP authentication scheme offers superior performance with a little extra computational cost.

Abstract

In this paper, we devise a new and efficient biometric-based password authentication scheme (BIO-PWA) for the client-server environment. Our scheme uses the elliptic curve cryptography (ECC) along with the fuzzy extractor. Through the rigorous security analysis, we show that our scheme is secure against various known attacks. We further show that our scheme is secure in the generic group model through the formal security analysis. In addition, the formal security verification of our scheme using the widely-accepted automated validation of internet security protocols and applications (AVISPA) tool is performed against active and passive adversaries and the simulation results clearly demonstrate that our scheme is secure against active and passive attacks, including the replay and man-in-the-middle attacks. Finally, we show that our scheme is also efficient in computation against the existing related ECC-based authentication schemes for the client-server environment.

Abstract

The energy cost of asymmetric cryptography is a vital component of modern secure communications, which inhibits its wide spread adoption within the ultra-low energy regimes such as Implantable Medical Devices (IMDs) and Radio Frequency Identification (RFID) tags. The ciphertext-policy attribute-based encryption (CP-ABE) is a promising cryptographic tool, where an encryptor can decide the access policy that who can decrypt the data. Thus, the data will be protected from the unauthorized users. However, most of the existing CP-ABE schemes require huge storage and computational overheads. Moreover, CP-ABE schemes based on bilinear map loose the high efficiency over the elliptic curve cryptography because of the requirement of the security parameters of larger size. These drawbacks prevent the use of ultra-low energy devices in practice. In this paper, we aim to propose a novel expressive AND-gate access structured CP-ABE scheme with constant-size secret keys (CSSK) with the cost efficient solutions for the encryption and decryption using ECC, called the CP-ABE-CSSK scheme. In the proposed CP-ABE-CSSK, the size of secret key is as small as 320 bits. In addition, ECC is efficient and more suitable for the lightweight devices as compared to the bilinear pairing based cryptosystem. Thus, the proposed CP-ABE-CSSK scheme provides the low computation and storage overheads with an expressive AND-gate access structure as compared to the related existing schemes in the literature. As a result, our scheme is very suitable for CP-ABE key storage and computation cost in the ultra-low energy devices.

Abstract

In communication systems, authentication protocols play an important role in protecting sensitive information against a malicious adversary by means of providing a variety of services such as mutual authentication, user credentials' privacy, and user revocation facility when the smart card of the user is lost/stolen or user's authentication parameters are revealed. Recently, several three‐party authentication with key agreement (3PAKA) schemes are proposed in the literature, but most of them do not provide the basic security requirements such as user anonymity as well as user revocation and re‐registration with the same identity. Thus, we feel that there is a great need to design a secure 3PAKA scheme with these security properties. In this paper, we propose a new secure biometric‐based privacy‐preserving 3PAKA scheme using the elliptic curve cryptography with efficient mechanism for the user revocation and re‐registration with the same identity. The formal security analysis using the widely accepted Burrows–Abadi–Needham logic shows that our scheme provides secure authentication. In addition, we simulate our scheme for the formal security verification using the widely accepted Automated Validation of Internet Security Protocols and Applications tool. The simulation results show that our scheme is secure against passive and active attacks. Furthermore, our scheme is efficient as compared with other related schemes. Our scheme provides high security along with low computation and communication costs, and extra features as compared with other related existing schemes in the literature, and as a result, our scheme is suitable for battery‐limited mobile devices.

Abstract

We consider a conformal model involving two real scalar fields in which the conformal symmetry is broken by a soft mechanism and is not anomalous. One of these scalar fields is representative of the standard model Higgs. The model predicts exactly zero cosmological constant. In the simplest version of the model, some of the couplings need to be fine-tuned to very small values. We formulate the problem of fine tuning of these couplings. We argue that the problem arises since we require a soft mechanism to break conformal symmetry. The symmetry breaking is possible only if the scalar fields do not evolve significantly over the time scale of the Universe. Ignoring contributions due to quantum gravity, we present two solutions to this fine tuning problem. We argue that the problem is solved if the classical value of one of the scalar fields is super-Planckian, i.e. takes a value much larger than the Planck mass. The …

Abstract

For critical applications, real‐time data access is essential from the nodes inside a wireless sensor network (WSN). Only the authorized users with unique access privilege should access the specific, but not all, sensing information gathered by the cluster heads in a hierarchical WSNs. Access rights for the correct information and resources for different services from the cluster heads to the genuine users can be provided with the help of efficient user access control mechanisms. In this paper, we propose a new user access control scheme with attribute‐based encryption using elliptic curve cryptography in hierarchical WSNs. In attribute‐based encryption, the ciphertexts are labeled with sets of attributes and secret keys of the users that are associated with their own access structures. The authorized users with the relevant set of attributes can able to decrypt the encrypted message coming from the cluster heads. Our scheme provides high security. Moreover, our scheme is efficient as compared with those for other existing user access control schemes. Through both the formal and informal security analysis, we show that our scheme has the ability to tolerate different known attacks required for a user access control designed for WSNs. Furthermore, we simulate our scheme for the formal security verification using the widely‐accepted automated validation of Internet security protocols and applications tool. The simulation results demonstrate that our scheme is secure.

Abstract

We study the implications of the ELKO fermions as a cold dark matter candidate. Such fermions arise in theories that are not symmetric under the full Lorentz group. Although they do not carry electric charge, ELKOs can still couple to photons through a nonstandard interaction. They also couple to the Higgs but do not couple to other standard model particles. We impose limits on their coupling strength and the ELKO mass assuming that these particles give dominant contribution to the cosmological cold dark matter. We also determine limits imposed by the direct dark matter search experiments on the ELKO-photon and the ELKO-Higgs coupling. Furthermore we determine the limit imposed by the gamma ray bursts time delay observations on the ELKO-Higgs coupling. We find that astrophysical and cosmological considerations rule out the possibility that ELKO may contribute significantly as a cold dark matter …