Vishwas Patil

Learn More
One-way hash chains have been the preferred choice (over symmetric and asymmetric key cryptography) in security setups where efficiency mattered; despite the ephemeral confidentiality and authentication they assure. They only support forward secrecy and have limitations over the chain size (bounded). In this paper, we show how the use of chameleon functions(More)
There has been an enormous increase of transactions and cooperative-computing services on the Internet. This is both a technical and a social phenomenon. Transactions and services over the Internet have global reach and users, known or unknown to the service provider, might be interested in availing the access or participate in the cooperative transaction(More)
In this paper, we propose a new efficient and secure micro-payment scheme, named e-coupons, which can provide the users the facility of delegating their spending capability to other users or their own devices like Laptop, PDA, Mobile Phone, and such service access points. The scheme has the promise of becoming an enabler for various Internet-based services(More)
Security over the Internet depends on a clear distinction between authorized and un-authorized principals. Discriminating between the two involves: identification (user identifies himself/herself), authentication (the system validates the user’s identity) and authorization (specific rights granted). Thus, it is important to develop specifications for access(More)
BACKGROUND AND OBJECTIVE Restoration of carious lesions with a strong permanent bond would be a highly desirable requisite. Ultra morphological characterization shows that observing and understanding the interfacial phenomenon and its quality would be of great importance in the selection of a dental adhesive for its use in pediatric restorative dentistry.(More)
Access control models need to be interoperable when administrative domains with heterogeneous access control models need to collaborate. Even, collaboration among homogeneous access control models is not straight-forward due to the different security orderings they might employ. In this paper, we briefly put forward an overlay formation mechanism based on(More)
Functional, esthetic and biologic restoration of a fractured incisor often presents a daunting clinical challenge. The outcome of conventional composites, prosthodontic restorations in a young patients result in an uncertain longevity of the same. Reattachment of the fractured fragment of a tooth helps in maintaining both morphology and esthetics in a(More)
In this paper, we shall describe the design and implementation of our Role-based Authorization and Delegation System (ROADS), based on the SPKI/SDSI framework. We have devised a flexible access control mechanism called flexi-ACL that allows us to integrate different kinds of authentication schemes in our setup. Using such flexible access control schemes, we(More)