Methods, devices and computer programs for creating ciphertext, plaintext and a cryptographic key

摘要

In an embodiment of a method of creating ciphertext, the embodiment includes the step of providing an authority with a piece of information that is associated with an entity. The embodiment also includes the step of acquiring from the authority a cryptographic key that is based on the piece of information. In addition to the previous two steps, the embodiment includes the step of encrypting plaintext with an encryption process that uses the cryptographic key to thereby create the ciphertext.