Increasing security against determination of encryption key, by evaluating input data based on check of predetermined criteria and calculating cipher text accordingly

摘要

Input data in the form of plain text and a key are subject to a check in terms of predetermined criteria. Based on the check, at least part of the input data is assigned an evaluation. An encryption algorithm is applied to the key and the plain text to calculate cipher text or an intermediate result in accordance with the evaluation. Independent claims are included for the use of the method to resist attack; for a data carrier on which the method is implemented; and for a method of personalizing a data carrier.