Reconfigurable random bit storage using polymer-dispersed liquid crystal: Supplementary information

As described in the main text, our ROSS key set is generated through the following steps: 1) detect a sequence of uncorrelated speckle intensity images, 2) unwrap each image into a 1D vector, 3) multiply each of these vectors by the random matrix projection operator H, 4) concatenate the results of these matrix multiplications into a single vector, comprising the key set. These four steps are sequentially explained in the following three sections. Before getting into details, we first demonstrate that the end product of the ROSS device is indeed statistically random and hence suitable as a random bit source (and secure storage mechanism) for nearly any cryptographic application.