Oblivious array shuffling in trusted execution environments

A non-transitory computer-readable medium having encoded therein programming code executable by one or more processors to perform or control performance of operations comprising:

• receiving an array having an array size and two or more non-null elements located in initial-arbitrary locations in the array;
• receiving a pseudo-random function (PRF) key;
• initializing an output array to null;
• shuffling at least a portion of the non-null elements to generate shuffled locations for the non-null elements, the shuffling of a first non-null element of the non-null elements including:
• determining an intermediate shuffled location for the first non-null element as an application a PRF to the PRF key and the first non-null element modulo a modulo element;
• responsive to a location in the output array corresponding to the intermediate shuffled location being null, outputting a shuffled location in the output array for the first non-null element as the intermediate shuffled location;
• response to the location in the output array corresponding to the intermediate shuffled location not being null, generating an updated intermediate shuffled location to a sum of the intermediate shuffled location and one modulo the array size;
• and
• responsive to a location in the output array corresponding to the updated intermediate shuffled location being null, outputting the shuffled location in the output array for the first non-null element as the updated intermediate shuffled location;
• and
• returning the output array having the first non-null element in the location in the output array that corresponds to the shuffled location.