HexString returns a string of n cryptographically random lowercase hex characters.

IntN is like rand.IntN, but it is seeded on the stack and does not allocate or lock any RNG state.

Perm is like rand.Perm, but it is seeded on the stack and does not allocate or lock any RNG state.

Shuffle is like rand.Shuffle, but it does not allocate or lock any RNG state.