A method of encrypting a transmission unit of a generalized scalable bit-stream includes, for each atom of the transmission unit, concatenating bit-stream segments that map to the atom to obtain data for each atom. The data for a logically first atom of the plurality of atoms of the multi-dimensional scalable representation is encrypted using an initialization input to produce an encryption output seed of the logically first atom and an encrypted logically first atom. In addition, the data of other atoms are encrypted to produce encrypted other atoms and an encryption output seed of each encrypted other atom. Encryption of a particular atom of the other atoms includes using encryption output seeds of adjacent causal atoms of the particular atom as an encryption input seed for encrypting the particular atom.