Disclosed examples of secure communications involve generating, by a mobile communication network device, a shared secret data having a length of M units. A first operation on groups of one of N units of a randomly generated base shared secret data and one of a plurality of secret values thereby generates a plurality of first operation results. A second operation on a select plurality of the first operation results generates a plurality of second operation results. The randomly generated base shared secret data can have a length of N units, where N is less than M. The shared secret data is constructed from at least one of the first operation results and the plurality of second operation results.