Depends on what you're counting for determinism. Arc4Random uses the system entropy pool, so it's non-deterministic from a user perspective. In a more direct s

Depends on what you're counting for determinism. Arc4Random uses the system entropy pool, so it's non-deterministic from a user perspective. In a more direct sense, yes. If you're allowed to keep secrets (like internal state), it's possible to produce random numbers algorithmically for certain (weak) definitions of random, even with a deterministic machine. A simple example of this would be sequential bits of a normal number. As you strengthen your definition of randomness you pretty quickly get into non-computable territory though.