Secure secret sharing in the cloud

In this paper, we show how a dealer with limited resources is possible to share the secrets to players via an untrusted cloud server without compromising the privacy of the secrets. This scheme permits a batch of two secret messages to be shared to two players in such a way that the secrets are reconstructable if and only if two of them collaborate. An individual share reveals absolutely no information about the secrets to the player. The secret messages are obfuscated by encryption and thus give no information to the cloud server. Furthermore, the scheme is compatible with the Paillier cryptosystem and other cryptosystems of the same type. In light of the recent developments in privacy-preserving watermarking technology, we further model the proposed scheme as a variant of reversible watermarking in the encrypted domain

Reversible data hiding in JPEG images based on adjustable padding

In this paper, we propose a reversible data hiding scheme that enables an adjustable amount of information to be embedded in JPEG images based on padding strategy. The proposed embedding algorithm only modifies, in a subtle manner, an adjustable number of zero-valued quantised DCT coefficients to embed the message. Hence, compared with a state-of-the-art based on histogram shifting, the proposed scheme has a relatively low distortion to the host images. In addition to this, we found that by representing the message in ternary instead of in binary, we can embed a greater amount of information while the level of distortion remains unchanged. Experimental results support that the proposed scheme can achieve better visual quality of the marked JPEG image than the histogram shifting based scheme. The proposed scheme also outperforms this state-of-the-art in terms of the ease of implementation

CORRELATION IN THE BARBELL AND LOWER LIMB KINEMATICS PERFORMANCE PARAMETERS IN THE SNATCH LIFTS: A PILOT STUDY

In our knowledge, there was not a lot of research to understand the relationship of snatch lifting. Therefore, the purpose of this study was to investigate the relationship between the barbell and lower limb kinematics parameters during the second pull of the snatch lifts. There were two digital cameras to record the snatch lifts. The study used the Kwon 3D motion analysis system to obtain the barbell and lower limb kinematics parameters. They study used the Pearson’s product moment correlations to investigate the relationship between the barbell and lower limb kinematics parameters. The results showed the significant relationship between the maximum vertical height of the barbell and the maximum extension angle of the hip joint. It also showed the significant relationship between the maximum extension angle velocity of the knee joint and maximum extension angle of the knee joint. The present study suggests that increasing the muscle quality and power of the lower limbs will increase the maximum vertical velocity of the barbell

RELATIONSHIP BETWEEN THE KINEMATICS OF THE TRUNK AND LOWER EXTREMITIES AND BALL VELOCITY DURING THE OVERHAND THROW IN MALE CANOE POLO PLAYERS

The purpose of this study was to examine the relationship between the motion of the trunk and lower extremities and ball velocity during the overhand throw in canoe polo. Fifteen male national canoe polo team players participated in this study. The overhand throwing motion was captured using a three dimensional motion analysis system. Kinematic and temporal parameters in the trunk and lower extremities were measured and analyzed. Results indicated that five variables were associated with variations in ball velocity. Specifically, as ball velocity increased, canoe polo players showed an increased maximal angular velocity in trunk-tilt sideways, upper torso rotation, and right knee flexion. In addition, the right knee flexion range of motion and time to maximum right knee flexion angular velocity increased as ball velocity increased

The Amnesiac Lookback Option: Selectively Monitored Lookback Options and Cryptocurrencies

This study proposes a strategy to make the lookback option cheaper and more practical, and suggests the use of its properties to reduce risk exposure in cryptocurrency markets through blockchain enforced smart contracts and correct for informational inefficiencies surrounding prices and volatility. This paper generalizes partial, discretely-monitored lookback options that dilute premiums by selecting a subset of specified periods to determine payoff, which we call amnesiac lookback options. Prior literature on discretely-monitored lookback options considers the number of periods and assumes equidistant lookback periods in pricing partial lookback options. This study by contrast considers random sampling of lookback periods and compares resulting payoff of the call, put and spread options under floating and fixed strikes. Amnesiac lookbacks are priced with Monte Carlo simulations of Gaussian random walks under equidistant and random periods. Results are compared to analytic and binomial pricing models for the same derivatives. Simulations show diminishing marginal increases to the fair price as the number of selected periods is increased. The returns correspond to a Hill curve whose parameters are set by interest rate and volatility. We demonstrate over-pricing under equidistant monitoring assumptions with error increasing as the lookback periods decrease. An example of a direct implication for event trading is when shock is forecasted but its timing uncertain, equidistant sampling produces a lower error on the true maximum than random choice. We conclude that the instrument provides an ideal space for investors to balance their risk, and as a prime candidate to hedge extreme volatility. We discuss the application of the amnesiac lookback option and path-dependent options to cryptocurrencies and blockchain commodities in the context of smart contracts