Abstract: A method of encrypting or obfuscating a first dataset, the dataset comprising a plurality of data elements, the method comprising distributing the data elements among one and at least one other of a plurality of discrete further datasets. Also provided is a method of reconstructing a first dataset from two or more further datasets, comprising mapping the said two or more further datasets onto one another. Inter alia, the disclosure further provides apparatus and documents comprising a plurality of layers, wherein the layers may be rotated, separated or otherwise manipulated to encrypt, obfuscate or reconstruct an object, pattern or image formed by the layers.