1. A computer-implemented digital steganography method comprising: providing a processor with a plurality of target data elements each comprising a sequence of digital bits; providing the processor with a plurality of source data elements each comprising a sequence of digital bits and has a specific start bit; and using a processor to generate, according to a predefined extraction method, a mapping of each of the target data elements with a corresponding source data element, wherein the mapping comprises, for each target data element, a corresponding indice indicating the position of the specific start bit within a bitwise representation of the source data elements irrespective of the bitwise position of each of the source data elements.