PROTECTION OF SOFTWARE MODELS

An encryption method is provided that has a software model of a technical system, the model including software components is encrypted by a public key and a decryption structure, wherein the latter includes definitions of component groups of the software model. The decryption structure is integrated at least partially into the encrypted software model. Correspondingly, in a decryption method according to the invention, via a secret key that likewise comprises definitions of component groups, only the particular component groups are decrypted whose definitions the secret key includes in agreement with the definitions of the encrypted software model. The definitions of the secret key can be extended after the fact by a key extension, so that additional component groups can be decrypted with an extended secret key.