A method of processing a multimedia fragment into two or more variants of the multimedia fragment, each variant having a different watermark, the method comprising: fragmenting a multimedia content into a sequence of fragments; watermarking a plurality of the fragments to create two or more variants of each of the plurality of fragments, wherein the two or more variants of one fragment are watermarked using different watermarks; adjusting the length of the two or more variants for at least one of the fragments to a same adjusted length, wherein the adjusted length is indicative of a temporal position of the two or more variants of the at least one of the fragments compared to variants of other fragments in the sequence of fragments.