Abstract: The invention is directed to a metal hollow fiber electrode, to a method of electrolyzing carbon dioxide in an aqueous electrochemical cell, to a method of converting carbon dioxide, to a method of preparing a metal hollow fiber, to a use of a metal hollow fiber electrode. The metal hollow fiber electrode comprises aggregated copper particles forming an interconnected three-dimensional porous structure, wherein said metal comprises copper.

Abstract: A computer-implemented method of authenticating an operation using a smart card, the smart card comprising respective information elements for authenticating respective ones of plural operations, each information element being associated with a respective security element, the method comprising (a) receiving an input from a user, (b) attempting to validate the input for each of the respective security elements, and (c) upon successful validation with one of the respective security elements, authenticating the operation using the information element for the one of the plural operations with which said one of the respective security elements is associated. Also a device, a smart card and a computer program.