Data processing device and method of processing data

A data processing device includes a memory and a processor. The memory is configured to store a computer program and N sets of private keys, in which N is a positive integer. The processor is coupled to the memory and configured to execute the computer program to perform: generating a first string according to a first data; generating a second string by inverting the first string; generating a third string according to the N sets of private keys and the second string; generating a first encrypting string by encrypting the third string; generating a fourth string by inverting the first encrypting string; generating a second encrypting string by encrypting the fourth string; and outputting the second encrypting string as a second data.