The present disclosure relates to a method for ensuring the authenticity of a field device. The method includes a step of assigning a unique authentic identification feature to the field device or providing the field device with a unique authentic identification feature. The method also includes steps of transmitting ACTUAL identification data to a participant node which transmits the ACTUAL identification data to the other participant nodes in a transaction, validating the transaction by the participant nodes, and creating a data block containing the transaction, wherein the data block is transmitted to each of the participant nodes. The method also includes verifying the data block by all participant nodes, storing the validated data block in the databases, comparing the ACTUAL identification data with corresponding TARGET identification data or original identification data from an authentication point, and generating a response containing the result of the comparison.