Can you enhance exercise-induced fat oxidation with green tea drinking?

Green tea is associated with health benefits. Some studies showed enhanced exercise-induced fat oxidation with intake of capsulated green tea components, primarily with epigallocatechin-3-O-gallate, but that effect was never observed with drinking brewed green tea from unpowdered leaves. In 2013, Hodgson et al. published a review article on green tea intake and exercise-induced fat oxidation. This review will cover some of the green tea studies since 2013 with only one study on the effects of drinking green tea. A study in 2018 showed that drinking a few cups with normal amounts of powdered green tea leaves (i.e. Matcha) enhanced fat oxidation during brisk walking in females. Capsulated intake of green tea components but also regular drinking of normal amounts of Matcha have the potential to provide benefits for health and exercise

Privacy leakage in biometric secrecy systems

Motivated by Maurer [1993], Ahlswede and Csiszar [1993] introduced the concept of secret sharing. In their source model two terminals observe two correlated sequences. It is the objective of both terminals to form a common secret by interchanging a public message (helper data), that should contain only a negligible amount of information about the secret. Ahlswede and Csiszar showed that the maximum secret key rate that can be achieved in this way is equal to the mutual information between the two source outputs. In a biometric setting, where the sequences correspond to the enrollment and authentication data, it is crucial that the public message leaks as little information as possible about the biometric data, since compromised biometric data cannot be replaced. We investigate the fundamental trade-offs for four biometric settings. The first one is the standard (Ahlswede-Csiszar) secret generation setting, for which we determine the secret key rate - privacy leakage region. Here leakage corresponds to the mutual information between helper data and biometric enrollment sequence conditional on the secret. In the second setting the secret is not generated by the terminals but independently chosen, and transmitted using a public message. Again we determine the region of achievable rate - leakage pairs. In setting three and four we consider zero-leakage, i.e. the public message contains only a negligible amount of information about the secret and the biometric enrollment sequence. To achieve this a private key is needed which can be observed only by the terminals. We consider again both secret generation and secret transmission and determine for both cases the region of achievable secret key rate - private key rate pairs

On the security of XOR-method in biometric authentication systems

A biometric authentication system can be partitioned into a layer that extracts common randomness out of a pair of related biometric sequences [Maurer, 1993] and a layer that masks a key sequence with this common randomness. We will analyze the performance of such a layered system first, and will show that an alternative method, the XOR- echnique, is not always secure