Methods and systems are described that enable protection of digital content, such as movies and the like, by making pirated copies traceable back to a unique decryption key that was utilized to decrypt the originally encrypted content. The innovative advancements do not rely on post-distribution watermarking or fingerprinting techniques, and yet intrinsically link any unauthorized copies back to a unique cryptographic key or key collection that was used when the genuine copy was reproduced. In one embodiment, digital content is provided and comprises multiple partition sets, with each partition set comprising a first partition and at least one different version of the first partition. Each partition of each partition set is uniquely marked and encrypted with a different key. Individual unique key collections are then defined to contain, for each partition set, one key that was used to encrypt a partition from the partition set and no two key collections are identical. This means that each key collection can decrypt one unique version of the digital content. This unique version of the digital content is thus inextricably tied to the key collection that was utilized to decrypt the content. Each key collection is then encrypted with a different public key associated with one of multiple content players on which the digital content is to be played. Thus, each content player is inextricably associated with one key collection, and each key collection is inextricably associated with a unique version of the digital content. The digital content and one or more key collections can then be provided to the content players. When a content player decrypts its associated key collection and uses the key collection to decrypt the digital content, the version of the digital content that is decrypted points directly to the specific content-player that was authorized to decrypt it with that key collection.