Abstract: An authentication method for trusted communication between a first party (A) and a second party (B) is intended to be efficient and secure. For this purpose, provision is made to combine password-based authentication and certificate-based authentication. For certificate-based authentication, the first party (A) has a static key pair consisting of a private static key and a public static key and a certificate for the public static key issued by a certification body (C). The certification body (C) is assigned a public key which is known by the second party (B). During the certificate-based authentication, the party A calculates a transformation between its own ephemeral key pair from the password-based authentication and its own static key pair from the certificate-based authentication so as to obtain a transformation parameter for carrying out the transformation.

Abstract: An authentication method for trusted communication between a first party (A) and a second party (B) is intended to be efficient and secure. For this purpose, provision is made to combine password-based authentication and certificate-based authentication. For certificate-based authentication, the first party (A) has a static key pair consisting of a private static key and a public static key and a certificate for the public static key issued by a certification body (C). The certification body (C) is assigned a public key which is known by the second party (B). During the certificate-based authentication, the party A calculates a transformation between its own ephemeral key pair from the password-based authentication and its own static key pair from the certificate-based authentication so as to obtain a transformation parameter for carrying out the transformation.

Abstract: A composite shaft/disc workpiece which is assembled from a disc with a passage hole and from a shaft by friction welding is disclosed. The outer wall of the shaft has a plurality of steps in the connection region with the disc, the radius of the steps becoming larger in a direction of the axis. The passage hole of the disc is provided with webs, the radius of which likewise becomes larger in a direction of the axis and between which annular recesses are present. The webs and steps to be connected overlap in the radial direction, so that, during the welding of the shaft and disc, annular connecting portions are obtained in the region of the webs and steps, annular cavities being formed between the connecting portions. The cavities represent a weight saving, as compared with composite shaft/disc workpices made of solid material, and can also be used as parts of media ducts.