A characterization of predicate encryption (PE) with support for homomorphic operations is presented and we describe the homomorphic properties of some existing PE constructions. Even for the special case of IBE, there are few known group-homomorphic cryptosystems. Our main construction is an XOR-homomorphic IBE scheme based on the quadratic residuosity problem (variant of the Cocks’ scheme), w...

to investigate the effect of preprocessing techniques including contrast enhancement and illumination correction on retinal imagequality, a comparative study was carried out. we studied and implemented a few illumination correction and contrast enhancementtechniques on color retinal images to find out the best technique for optimum image enhancement. to compare and choose thebest illumination c...

Retinal image analysis has remained an essential topic of research in the last decades. Several algorithms and techniques have been developed for retinal images. Most these use benchmark datasets to evaluate performance without first exploring quality image. Hence, metrics evaluated by approaches are uncertain. In this paper, images is selected utilizing hybrid naturalness evaluator perception-...

DOI 10.1007/978-1-4419-7222-4_7, © Springer Science+Business Media, LLC 2011 Abstract It is well known that speckle is a multiplicative noise that degrades the visual evaluation in ultrasound imaging. This necessitates the need for robust despeckling techniques for both routine clinical practice and tele-consultation. The recent advancements in ultrasound instrumentation and portable ultrasound...

In homomorphic encryption schemes, anyone can perform homomorphic operations, and therefore, it is difficult to manage when, where and by whom they are performed. In addition, the property that anyone can “freely” perform the operation inevitably means that ciphertexts are malleable, and it is well-known that adaptive chosen ciphertext (CCA) security and the homomorphic property can never be ac...

Homomorphic signature schemes are an important primitive for many applications and since their introduction numerous solutions have been presented. Thus, in this work we provide the first exhaustive, complete, and up-to-dated survey about the state of the art of homomorphic signature schemes. First, the general framework where homomorphic signatures are defined is described and it is shown how ...

We propose multi target homomorphic attribute-based encryption (MT-HABE) with fully dynamic homomorphic evaluation: it can take as input arbitrary additional ciphertexts during homomorphic computation. In the previousMT-HABE of Brakerski et al. (TCC 2016-B), the output of homomorphic computation, which is related to a policy set, cannot be computedwith a fresh ciphertext whose attribute does no...

Quantum signature which concerns about the authenticity and non-repudiation of messages on insecure quantum channels is an important research topic in quantum cryptography. So far, a few quantum signature schemes have been proposed. Inspired by entanglement swapping, we first propose a new quantum homomorphic signature scheme which can be used to authenticate data packets of multiple streams fo...

Email is a private medium of communication, and the inherent privacy constraints form a major obstacle in developing effective spam filtering methods which require access to a large amount of email data belonging to multiple users. To mitigate this problem, we envision a privacy preserving spam filtering system, where the server is able to train and evaluate a logistic regression based spam cla...