You should pretty much just default to secure random.
/dev/urandom is fine; in Ruby apps, I'd use OpenSSL::Random.random_bytes or ActiveSupport::SecureRandom.random_number.
/dev/urandom is fine; in Ruby apps, I'd use OpenSSL::Random.random_bytes or ActiveSupport::SecureRandom.random_number.
Do those functions just read from /dev/urandom?