Method comprising: - receiving identification information on an addressee to whom an encrypted data object is to be sent from a sending device or for whom the encrypted data object is to be provided, by the sending device, for retrieval from the sending device at a server, - associating the identification information with a key for decrypting the encrypted data object by the server, - generating a certificate for a key for encrypting the data object by the server, wherein the server associates the certificate for the key for encrypting the data object with the key for decrypting the encrypted data object, wherein the server stores the association between the certificate for the key for encrypting the data object and the key for decrypting the encrypted data object in an entry in a database, wherein the key for decrypting the encrypted data object and the certificate for the key for encrypting the data object are stored in the entry in the database, wherein the key for encrypting the data object is a public key of an asymmetric encryption method, and wherein the key for decrypting the encrypted data object is a corresponding private key of the asymmetric encryption method, - sending the certificate for the key for encrypting the data object from the server to the sending device, - receiving a request for the key to decrypt the encrypted data object at the server, the request comprising authentication information of the addressee and the certificate for the key to encrypt the data object, - authenticating the addressee by the server, and - sending the key for decrypting the encrypted data object associated with the certificate for the key for encrypting the data object in the entry in the database to the addressee by the server or providing, by the server, the key for decrypting the encrypted data object associated with the certificate for the key for encrypting the data object in the entry in the database for retrieval by the addressee, wherein the server deletes the key for decrypting the encrypted data object after sending or providing. - receiving identification information on an addressee to whom an encrypted data object is to be sent from a sending device or for whom the encrypted data object is to be provided, by the sending device, for retrieval from the sending device at a server, - associating the identification information with a key for decrypting the encrypted data object by the server, - generating a certificate for a key for encrypting the data object by the server, wherein the server associates the certificate for the key for encrypting the data object with the key for decrypting the encrypted data object, wherein the server stores the association between the certificate for the key for encrypting the data object and the key for decrypting the encrypted data object in an entry in a database, wherein the key for decrypting the encrypted data object and the certificate for the key for encrypting the data object are stored in the entry in the database, wherein the key for encrypting the data object is a public key of an asymmetric encryption method, and wherein the key for decrypting the encrypted data object is a corresponding private key of the asymmetric encryption method, - sending the certificate for the key for encrypting the data object from the server to the sending device, - receiving a request for the key to decrypt the encrypted data object at the server, the request comprising authentication information of the addressee and the certificate for the key to encrypt the data object, - authenticating the addressee by the server, and - sending the key for decrypting the encrypted data object associated with the certificate for the key for encrypting the data object in the entry in the database to the addressee by the server or providing, by the server, the key for decrypting the encrypted data object associated with the certificate for the key for encrypting the data object in the entry in the database for retrieval by the addressee, wherein the server deletes the key for decrypting the encrypted data object after sending or providing.