Balasubramaniam Srinivasan

Dynamic Key Cryptography and Applications

In modern security models, cryptography plays a fundamental role in protecting data integrity and confidentiality in information systems. However, cryptography itself is subject to cryptanalysis attacks. To reduce the cryptanalysis attack risk, a dynamic key theory is presented and analyzed in this paper. Because these dynamic keys are one-time used symmetric cryptographic keys, they can significantly improve the security of cryptographic systems. The dynamic key theory generation scheme and key update mechanism are formally analyzed to demonstrate balance between security and performance. The theory can be applied to enhance the security and performance of cryptographic systems, especially those used in wireless networks communication. Two case studies using the proposed dynamic key theory are also described and analyzed to illustrate the power of the theory.

Analysis and Improvements over DoS Attacks against IEEE 802.11i Standard

To improve the ability of system providing service when encounter malicious invasion, a new model of tolerance invasion system is given based on dynamic threshold encryption. The real-time detection of the model is realized by the Collaboration between servers and hosts. The sensitive data in the system apply dynamic threshold encryption, and can change their share with the distribution. The model has such as distribution, self-adaptability, fault tolerance, dynamic and expansibility features to ensure that the system has a higher level of safety.

Constrained range search query processing on road networks

Range search is one of the most common queries in the spatial databases and geographic information systems (GIS). Most range search processing depends on the length of the distance that expresses the relative position of the objects of interest in the Euclidean space or road networks. But, in reality, the expected result is normally constrained by other factors (e.g. number of spatial objects, pre‐defined area, and so forth.) rather than the distance alone; hence, range search should be comprehensively discussed in various scenarios. In this paper, we propose two constrained range search approaches based on network Voronoi diagram, namely Region Constrained Range (RCR) and k nearest neighbor Constrained Range (kCR), which make the range search query processing more flexible to satisfy different requirements in a complex environment. The performance of these approaches is analyzed and evaluated to illustrate that both of them can process constrained range search queries very efficiently. Copyright

Partial Fingerprint Matching through Region-Based Similarity

Despite advances in fingerprint matching, partial/incomplete/fragmentary fingerprint recognition remains a challenging task. While miniaturization of fingerprint scanners limits the capture of only part of the fingerprint, there is also special interest in processing latent fingerprints which are likely to be partial and of low quality. Partial fingerprints do not include all the structures available in a full fingerprint, hence a suitable matching technique which is independent of specific fingerprint features is required. Common fingerprint recognition methods are based on fingerprint minutiae which do not perform well when applied to low quality images and might not even be suitable for partial fingerprint recognition. To overcome this drawback, in this research, a region-based fingerprint recognition method is proposed in which the fingerprints are compared in a pixel- wise manner by computing their correlation coefficient. Therefore, all the attributes of the fingerprint contribute in the matching decision. Such a technique is promising to accurately recognise a partial fingerprint as well as a full fingerprint compared to the minutiae-based fingerprint recognition methods.The proposed method is based on simple but effective metrics that has been defined to compute local similarities which is then combined into a global score such that it is less affected by distribution skew of the local similarities. Extensive experiments over Fingerprint Verification Competition (FVC) data set proves the superiority of the proposed method compared to other techniques in literature.

Hybrid Group Key Management Scheme for Secure Wireless Multicast

Along with the dramatic development of wireless network technologies and portable devices, wireless group applications are rapidly innovated to provide online services via wireless broadband networks. This development has led to a prime concern for providing clients with a secure and efficient key management system for group services such as multimedia conferencing, stock quoting and so on. In this paper we propose a new hybrid group key management approach which is suitable for the cellular wireless environment. This new approach has a two-level structure where the group users are sub-divided into clusters, hence reducing the rekeying cost in the key updating. We demonstrate that our proposed approach can achieve better efficiency when compared to the conventional Logical Key Hierarchy scheme.

Dynamic Keys Based Sensitive Information System

Protecting sensitive information systems from security threats such as unauthorised access, information eavesdropping and information interfering, is significant. Most of the natural approaches employ strong authentication or cryptography systems to protect critical data. But those approaches do not stress on the potential amount of risks associated with sensitive information, especially the vulnerability from compromising of long term cryptographic keys and the lack of fine gained access control. Therefore, in this paper, a dynamic key theory based secure sensitive information system is proposed, which integrates dynamic keys with raw data to protect sensitive information; and the system also uses the keys to secure communication and enhance access control. A formal analysis is provided to verify the security of the proposed work. It shows that the proposed system guarantees critical information data security and access control flexibility. In addition, by using two sets of dynamic keys, fraud detection and prevention is achieved in the proposed system.

Adaptive approach to fingerprint image enhancement

The purpose of fingerprint image enhancement is to improve the clarity and quality of its local features. The quality of fingerprint image determines the accuracy and reliability of minutia extraction which also determines the accuracy of an automatic fingerprint recognition system. In this paper, we propose an adaptive image pre-processing approach that can significantly improve poor quality images according to their noise level based on contrast stretching, power-law transformation and Gabor filter. The original image smoothing is performed initially by Gaussian filter, and then processed by the proposed adaptive algorithm, and finally the resultant image is filtered by Gabor filter to get the improved binarized image. Experimental results indicate that the proposed approach improves the quality of image and reduces the noise significantly as compared to other fingerprint image preprocessing approaches. Furthermore, the result of Goodness Index (GI) shows that our proposed approach improves the performance by 9% as compared to conventional Gabor filter based approach and is also better than other reported results. Especially, the performance of GI is improved by more than 40% in some poor quality images.

Approximate storage utilization of B-trees

Abstract A recent paper by Leung (1984) has presented a new simple derivation of the approximate average utilization of B-trees. This paper presents two weaknesses of that derivation and shows how these might be overcome.

Security Analysis and Improvements on WLANs

IEEE 802.11i standard defines the security specifications of IEEE 802.11 series Wireless Local Area Network (WLAN). It is the replacement of the old security standard named Wired Equivalent Privacy (WEP), and it aims to eliminate all known attacks against WEP. It well defines the solutions to the confidentiality, mutual authentication and integrity aspects of the WLAN security except the availability aspect. Many researchers have shown that IEEE 802.11i standard cannot prevent various Denial of Service (DoS) attacks including de-authentication, disassociation and memory/CPU DoS attacks. Besides, IEEE 802.11i reserved the PSK mode of WEP for flexibility and backward compatibility. However, the PSK mode in IEEE 802.11i standard fails to provide sufficient security to prevent offline dictionary attacks and internal attacks . In this paper, we present our solutions which can effectively improve IEEE 802.11i. For memory/CPU DoS attack against 4-way Handshake protocol, we propose an alternative Enhanced 3-way Handshake protocol which can effectively prevent this attack and can save computation cost compared to the original one . For the vulnerability in PSK mode, we proposed a novel ECDH protocol to prevent the offline dictionary attacks and internal attacks. The formal proofs of above two proposed protocols are also provided using Protocol Composition Logic (PCL).

Formal Verification of a Secure Mobile Banking Protocol

Current mobile banking protocols simply are not as well guarded as their Internet counterparts during the transactions between a mobile device and a financial institution. Recently, many mobile banking protocols using public-key cryptography have been proposed. However, they are designed to provide a basic protection for traditional flow of payment data as they only rely on basic identification and verification mechanisms, which is vulnerable to attack and increase the user’s risk. In this paper we propose a new secure mobile banking protocol that provides strong authentication mechanisms. These mechanisms rely on highly usable advanced multifactor authentication technologies i.e. (biometrics and smart cards). The proposed mobile banking protocol not only achieves a completely secure protection for the involved parties and their financial transactions but also minimizes the computational operations and the communication passes between them. An analysis and a proof of the proposed protocol security properties will be provided within this paper.