It is well known that any encryption scheme which supports any form of homomorphic operation cannot be secure against adaptive chosen ciphertext attacks. The question then arises as to what is the most stringent security definition which is achievable by homomorphic encryption schemes. Prior work has shown that various schemes which support a single homomorphic encryption scheme can be shown to...

Consider a decision problem that cannot be 1 ? approximated by circuits of a given size in the sense that any such circuit fails to give the correct answer on at least a fraction of instances. We show that for any such problem there is a speciic \hard-core" set of inputs which is at least a fraction of all inputs and on which no circuit of a slightly smaller size can get even a small advantage ...

This paper reviews some of the work in the area of statistical circuit design. While space does not permit a more then superficial survey of the entire field, specific emphasis is placed on those techniques more familiar to the authors.

Linear approximations of modular addition modulo a power of two was studied by Wallen in 2003. He presented an efficient algorithm for computing linear probabilities of modular addition. In 2013 Schulte-Geers investigated the problem from another viewpoint and derived a somewhat explicit formula for these probabilities. In this note we give a closed formula for linear probabilities of modular a...

At 532 nm wavelength, optical properties of black carbon (BC) particles mixed with sulfate are computed by use of two morphological models, a closed cell and a coated aggregate model. For high BC volume fractions f, both models yield comparable results. As more sulfate is added, some of the optical properties diverge. The backscattering depolarization ratio δL is particularly sensitive to the m...

The influence of problem-based learning (PBL) and open-book tests on long-term knowledge retention is unclear and subject of discussion. Hypotheses were that PBL as well as open-book tests positively affect long-term knowledge retention. Four progress test results of fifth and sixth-year medical students (n = 1,648) of three medical schools were analyzed. Two schools had PBL driven curricula, a...