It is described a method for encrypting and a method for decrypting at least a portion (155) of a dataset being stored in a memory (150), wherein the dataset has at least two dimensions. The described multi-dimensional cryptographic methods comprise forming a first keystream (165) being assigned to a first dimension of the dataset and forming a second keystream (175) being assigned to a second dimension of the dataset. The encrypting method further comprises encrypting each data packet of the portion (155) of the dataset by using a combination of the first keystream (165) and the second keystream (175). The decrypting method further comprises decrypting each data packet of the portion (155) of the dataset by using a combination of the first keystream (165) and the second keystream (175). It is further described a method for temporarily storing at least a portion (155) of a dataset into a memory (150) and a device for handling a dataset, which method and which device take advantage of the above-described encrypting method and/or the above-described decrypting method.