A random number generator (RNG) resistant to side channel attacks includes an activation pseudo random number generator (APRNG) having an activation output connected to an activation seed input to provide a next seed to the activation seed input. A second random number generator includes a second seed input, which receives the next seed and a random data output, which outputs random data in accordance with the next seed. An input seed memory is connected to the activation seed input and a feedback connection from the activation output so that the next seed is stored in the input seed memory to be used by the APRNG as the activation seed input at a next startup cycle.