Method and apparatus for authenticating multicast messages

Abstract

Method for authenticating a multicast message having the following steps: An initialization hash chain is calculated (S1) by a transmitter on the basis of an anchor value for the transmitter, and the last chain link in the initialization hash chain is distributed as an initialization function value to at least one receiver in an initialization phase (IP), a multicast message (MC-N) is received (S2) by a receiver, which stores the received multicast message (MC-N), an authentication key release message (KRM) is received (S3) from the transmitter by the receiver, wherein the authentication key release message (KRM) contains a cryptographic authentication key (K) released by the transmitter for the purpose of authenticating the stored multicast message (MC-N), a cryptographic function value h (K) is calculated (S4) for the cryptographic authentication key (K) contained in the authentication key release message (KRM) by the receiver using a prescribed cryptographic function (H), the cryptographic function value h (K) - calculated by the receiver - of the authentication key (K) is compared (S5) with the initialization function value (hn) distributed to receivers by the transmitter in advance in the initialization phase (IP) for the purpose of checking the validity of the cryptographic authentication key (K) contained in the authentication key release message (KRM); and the multicast message (MC-N) which comes from the transmitter and which is stored in the receiver is authenticated (S6) by the receiver using the cryptographic authentication key (K) which has been recognized as valid.

Description

technical field [0001] The present invention relates to a method and a device for authenticating multicast messages, especially for field devices exchanged between peer-to-peer systems and containing GOOSE (Generic Object Oriented Substation Events: Generic Object Oriented Substation Events: Generic Object Oriented Substation Events) as valid data respectively. Event) message or a multicast message of an SMV (Sampled Measured Values) message and a method and device for authenticating. Background technique [0002] After detecting the event, the field device transmits the multicast message to other registered field devices, which receive the multicast message. These multicast messages are transmitted from the field device which has detected the event to the remaining field devices via a wireless or wired message connection. Such a field device can be, for example, a protective device such as an intelligent circuit breaker, which is located in a substation of the power supply...

AI Technical Summary

Problems solved by technology

[0003] However, this approach has significant disadvantages: there is a significant computational overhead for creating the digital signature and for verifying said data signature by all receiving field devices, and the relative The corresponding field device must have the corresponding resources for performing this calculation

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