A computer-implemented method for providing authorization keys, where the method includes receiving a further asymmetrical, cryptographic key pair, where the further asymmetrical key pair is part of a key pair sequence, where the further asymmetrical key pair includes a further first and a further second authorization key; retrieving a ciphertext, where the ciphertext is associated with the key pair which immediately precedes the further key pair in the sequence of key pairs, where the ciphertext includes the initial first key encrypted with the second authorization key of the key pair which immediately precedes the further key pair in the sequence of key pairs; decrypting the initial first authorization key using the first authorization key of the key pair which immediately precedes the further key pair in the sequence of key pairs; generating a further ciphertext through encryption of the decrypted initial first authorization key using the second authorization key of the further key pair; and saving the further ciphertext.