Traditional encryption schemes, both symmetric and asymmetric, were not designed to respect the algebraic structure of the plaintext and ciphertext spaces. Many schemes, such as ElGamal (resp. e.g. Paillier), are multiplicatively homomorphic (resp. additively homomorphic), so that one can perform certain limited types of computations directly on the encrypted data and have them pass through the...

Homomorphic encryption (HE) schemes enable computing functions on encrypted data, by means of a public Eval procedure that can be applied to ciphertexts. But the evaluated ciphertexts so generated may differ from freshly encrypted ones. This brings up the question of whether one can keep computing on evaluated ciphertexts. An i-hop homomorphic encryption scheme is one where Eval can be called o...

Closed-form solutions were developed to optimize kinematics design of a 2-degree-of-freedom (2DOF) planar parallel manipulator. The optimum design based on the workspace was presented. Meanwhile, a global, comprehensive conditioning index was introduced to evaluate the kinematic designs. The optimal parallel manipulator is incorporated into a 5-DOF hybrid machine tool which includes a 2-DOF rot...

BACKGROUND Assessing the clinical effectiveness of measuring grip strength as a prognostic tool in recovering ambulation in bed-confined frail elderly patients. METHODS A prospective study was carried out with 50 elderly inpatients (mean age: 81.6 years old). Manual muscle test was used for checking strength of hip flexor muscles, hip abductor muscles and knee extensor muscles. Grip strength ...

Recovering an un-blurred image from a single motion-blurred picture has long been a fundamental research problem. If one assumes that the blur kernel – or point spread function (PSF) – is shift invariant, the problem reduces to that of image deconvolution. Image deconvolution can be further categorized as non-blind and blind. In non-blind deconvolution, the motion blur kernel is assumed to be k...

Let A be a C∗-algebra and E : A → A a conditional expectation. The Kadison-Schwarz inequality for completely positive maps, E(x)∗E(x) ≤ E(x∗x), implies that ‖E(x)‖ ≤ ‖E(x∗x)‖ . In this note we show that E is homomorphic (in the sense that E(xy) = E(x)E(y) for every x, y in A) if and only if ‖E(x)‖ = ‖E(x∗x)‖ , for every x in A. We also prove that a homomorphic conditional expectation on a commu...

In this paper we propose improvements on the Helios voting protocol such that the audit data published by the authority provides everlasting privacy, as opposed to the computational privacy provided currently. We achieve this with minor adjustments to the current implementation. For the homomorphic Helios variant we use Pedersen commitments to encode the vote, together with homomorphic encrypti...