Online content have become an important medium to disseminate information and express opinions. With the proliferation of online document collections, users are faced with the problem of missing the big picture in a sea of irrelevant and/or diverse content. In this thesis, we addresses the problem of information organization of online document collections, and provide algorithms that create a s...

An undeniable mobile billing system allows a mobile network service provider to bill its subscribers with trustworthy evidences. Chen, Jan and Chen proposed such a billing system by introducing a trusted third party – Observer and exploiting a hash chain mechanism. In their system, the Observer provides call time evidence to both cellular carriers and subscribers for billing. In this paper, we ...

The subliminal channel in a cryptographic protocol such as an authentication system or a signature scheme provides an additional channel from the sender to an authorized receiver and can’t be read by any unauthorized receiver. In this paper, we firstly show that Hess’s ID-Based signature scheme in SAC’02 can provide digital signature with the broadband and narrowband subliminal channels. Second...

BACKGROUND In Gujarat, India, a state led public private partnership scheme to promote facility birth named Chiranjeevi Yojana (CY) was implemented in 2005. Institutional birth is provided free of cost at accredited private health facilities to women from socially disadvantaged groups (eligible women). CY has contributed in increasing facility birth and providing substantially subsidized (but n...

Microgravity decreases osteoblastic activity, induces actin microfilament disruption and inhibits the responsiveness of osteoblast to cytokines, but the mechanisms remains enigmatic. The F-actin cytoskeleton has previously been implicated in manifold changes of cell shape, function and signaling observed under microgravity. Here we investigate the involvement of microfilament in mediating the e...

The access privileges in distributed systems are often organized as a hierarchy structure. Chien and Jan proposed an efficient hierarchical key assignment scheme without using the public key cryptosystem in 2003. Nevertheless, their scheme must use the smart card and the information published on the public board contains the essential secrets of the server and the corresponding users. We theref...