Abstract: A method and a device are described for determining the optical center point of the lenses of spectacles to be manufactured for a spectacle wearer, whose head is imaged from the front using a digital camera (10), wherein the location of the pupils (16) and the interpupillary distance (20, 21) are determined with the aid of an image evaluation program to define the optical center point of the lenses.

Abstract: Webpages to which different web addresses are assigned and which are stored in the form of web data on different computer systems that are connected to one another via a communications protocol, preferably the Hypertext Transfer Protocol. First, at least the layout, content and/or the graphical elements of a reference webpage are determined in the form of reference data and then a plurality of different webpages are called up by a search and analysis routine and the sets of web data associated with the called-up webpages is compared with the reference data. The webpages that are similar to the reference webpage are identified as a function of the degree of agreement between the web data and the reference data.

Abstract: The process is intended to establish whether the data transmitted by the transmitter (SE) to the receiver (EM) have been tapped and spuriously reintroduced at a later point in time and/or have been inadmissibly altered. For this purpose, the signature (S) assigned to the useful data (D) is enciphered symmetrically, using a combination of coupling data (K), characterizing the coupling between transmitter and receiver, and random data (Z), generated by a random generator. The coupling data are transmitted in plain text, the random data are enciphered. On the receiver side it can be established whether the transmitted message has been tapped and reintroduced at a later point in time if the coupling data are inadmissible.