What about a stream cipher like ChaCha20? Also would data-dependencies be different on a GPU than with parallelization on a CPU? Because modes like GCM (i.e.

What about a stream cipher like ChaCha20? Also would data-dependencies be different on a GPU than with parallelization on a CPU? Because modes like GCM (i.e. CTR) both the encryption and decryption are parallelizable (with CBC it's just decryption). I wonder if AMD GPU's would be better suited to the task than Nvidia's (at least their existing GPU's) provided you could actually saturate the GPU with enough work to make it worth it.