A data encryption-decryption method includes the steps of receiving a data byte N and performing a triple-churning operation on byte N to obtain an encrypted byte N. Preferably, the triple-churning operation includes performing a first churning operation to obtain a first churned output, bit-wise XORing the first churned output with two values to obtain a first XOR result, performing a second churning operation on the first XOR result to obtain a second churned output, bit-wise XORing the second churned output with two values to obtain a second XOR result, and performing a third churning operation on the second XOR result to obtain encrypted byte N.