4,8-dimethyl-3,7-nonadien-2-one has aromatizing properties and increases the extendibility and intensity of the aroma when used in an aroma composition. Furthermore, the exchange of encryption keys can be handled through, for example, a secure socket connection between the client and a server thus removing the requirement of the user manually decrypting the transferred file. Means for tightening the raceway include at least one guide member passing through the raceway to let a part of the elongate element slide freely transversely to the raceway, in front of the front edge of the raceway, elastically extensible means arranged along the elongate element, and securing means to connect at least one end of the elongate element to the front element. The storage space includes an interior portion and an exterior portion.