ars5#
The ars5 counter-based pseudorandom number generator.
Description
The ars5 engine is a keyed family of counter-based BRNG. The state consists of a 128-bit integer counter \(c\) and a 128-bit key \(k\). The BRNG is based on the AES encryption algorithm [FIPS-197].
Generation algorithm
The generator has a 32-bit integer output obtained in the following way [Salmon11]:
The i-th number is defined by the following formula \(r_i=(f(i/ 4) >> ((i \ mod \ 4) * 32)) \ mod \ 2 ^ {32}\)
- Function \(f(c)\) takes a 128-bit argument and returns a 128-bit number. The returned number is obtained as follows:
2.1. \(c_0 = c \oplus k\) and \(k_0 = k\).
2.2. The following recurrence is calculated N = 5 times:
\(c_{i+1} = SubBytes(c)\)
\(c_{i+1} = ShiftRows(c_{i+1})\)
\(c_{i+1} = MixColumns(c_{i+1})\), this step is omitted if \(i+1 = N\)
\(c_{i+1} = AddRoundKey(c_{i+1}, k_j)\)
\(Lo(k_{i+1}) = Lo(k) + 0x9E3779B97F4A7C15\)
\(Hi(k_{i+1}) = Hi(k) + 0xBB67AE8584CAA73B\)
Specification for \(SubBytes, ShiftRows, MixColumns, AddRoundKey\) functions can be found in [FIPS-197].
2.3. Put \(f(c) = c_N\), where \(N = 10\)
Real output: \(u_n=(int)r_n / 2^{32} + 1/2\)
class ars5#
Syntax
namespace oneapi::mkl::rng {
class ars5 {
public:
static constexpr std::uint64_t default_seed = 0;
ars5(sycl::queue queue, std::uint64_t seed = default_seed);
ars5(sycl::queue queue, std::initializer_list<std::uint64_t> seed);
ars5(const ars5& other);
ars5(ars5&& other);
ars5& operator=(const ars5& other);
ars5& operator=(ars5&& other);
~ars5();
};
}
Class Members
Routine |
Description |
---|---|
Constructor for common seed initialization of the engine |
|
ars5(sycl::queue queue, std::initializer_list<std::uint64_t> seed) |
Constructor for extended seed initialization of the engine |
Copy constructor |
|
Move constructor |
|
Copy assignment operator |
|
Move assignment operator |
Constructors
ars5::ars5(sycl::queue queue, std::uint64_t seed)
Input Parameters
- queue
Valid sycl::queue object, calls of the oneapi::mkl::rng::generate() routine submits kernels in this queue to obtain random numbers from a given engine.
- seed
The initial conditions of the generator state, assume \(k = seed, c = 0\), where \(k\) is 128-bit key, \(c\) is 128-bit counter.
ars5::ars5(sycl::queue queue, std::initializer_list<std::uint64_t> seed)
Input Parameters
- queue
Valid
sycl::queue
object, calls of the oneapi::mkl::rng::generate() routine submits kernels in this queue to obtain random numbers from a given engine.- seed
The initial conditions of the generator state, assume if \(n = 0: k = 0, c = 0\)
if \(n = 1: k = seed[0], c = 0\)
if \(n = 2: k = seed[0] + seed[1] \cdot 2^{64}, c = 0\)
if \(n = 3: k = seed[0] + seed[1] \cdot 2^{64}, c = seed[2]\)
if \(n = 4: k = seed[0] + seed[1] \cdot 2^{64}, c = seed[2] + seed[3] \cdot 2^{64}\)
for \(n > 4\) following arguments are ignored
ars5::ars5(const ars5& other)
Input Parameters
- other
Valid
ars5
object. Thequeue
and state of the other engine is copied and applied to the current engine.
ars5::ars5(ars5&& other)
Input Parameters
- other
Valid
ars5
r-value object. Thequeue
and state of the other engine is moved to the current engine.
ars5::ars5& operator=(const ars5& other)
Input Parameters
- other
Valid
ars5
object. Thequeue
and state of the other engine is copied and applied to the current engine.
ars5::ars5& operator=(ars5&& other)
Input Parameters
- other
Valid
ars5
r-value object. Thequeue
and state of the other engine is moved to the current engine.
Parent topic: Host Engines (Basic Random Number Generators)