Semiconductor device and semiconductor storage device

1. A semiconductor device comprising:

a seed generator circuit configured to:

generate first random number sequence data by performing a first XorShift operation on inputted data: and

generate a seed by using the first random number sequence data, and

a random number generator circuit configured to:

generate second random number sequence data by performing a second XorShift operation on the seed.

2. The semiconductor device according to claim 1 , wherein

the seed generator circuit includes a plurality of XorShift circuits, and a nonlinear transformation circuit configured to perform a nonlinear transformation on output data from at least one of the plurality of XorShift circuits, and

the first random number sequence data are generated by using the plurality of XorShift circuits and the nonlinear transformation circuit.

3. The semiconductor device according to claim 2 , wherein

the plurality of XorShift circuits include a first XorShift circuit and a second XorShift circuit,

the first XorShift circuit is configured to perform the first XorShift operation on the inputted data, and

the second XorShift circuit is configured to perform processing on output data from both the first XorShift circuit and the nonlinear transformation circuit to generate the seed.

4. The semiconductor device according to claim 3 , wherein

the random number generator circuit is configured to perform an XOR operation on an operation result of the second XorShift operation to generate the second random number sequence data.

5. The semiconductor device according to claim 3 , wherein

the random number generator circuit is configured to:

perform an XOR operation on an operation result from the second XorShift circuit, and

perform the second XorShift operation on an operation result of the XOR operation to generate the second random number sequence data.

6. The semiconductor device according to claim 2 , wherein

the nonlinear transformation circuit includes a plurality of S-box circuits configured to perform a nonlinear transformation of a same kind.

7. The semiconductor device according to claim 2 , wherein

the nonlinear transformation circuit includes a plurality of S-box circuits configured to perform a plurality of kinds of different nonlinear transformations.

8. The semiconductor device according to claim 7 , wherein

the plurality of S-box circuits include at least two S-box circuits configured to output different numbers of bits.

9. The semiconductor device according to claim 1 , further comprising:

an exchange circuit configured to exchange data positions in the second random number sequence data.

10. The semiconductor device according to claim 1 , wherein

the random number generator circuit includes an inversion circuit configured to perform bit inversion, byte inversion, or word inversion before or after performing the second XorShift operation.

11. The semiconductor device according to claim 1 , wherein

the random number generator circuit includes a first XorShift circuit, a second XorShift circuit, a first S-box circuit, and a second S-box circuit,

the first XorShift circuit includes a first input and a first output,

the second XorShift circuit includes a second input and a second output,

the first input is connected to an output of the first S-box circuit, and the first output is connected to an input the second S-box circuit, and

the second input is connected to an output of the second S-box circuit, and the second output is connected to an input of the first S-box circuit.

12. The semiconductor device according to claim 1 , wherein

the random number generator circuit includes a plurality of units, each of which includes a first XorShift circuit, a second XorShift circuit, a first S-box circuit, and a second S-box circuit,

in each of the plurality of units,

the first XorShift circuit includes a first input and a first output, and

the second XorShift circuit includes a second input and a second output,

the first input is connected to an output of the first S-box circuit, and the first output is connected to an input of the second S-box circuit,

the second input is connected to an output of the second S-box circuit, and the second output is connected to an input of the first S-box circuit, and

a bit shift amount used in the first and second XorShift circuits of each of the plurality of units differs among the plurality of units.

13. A semiconductor storage device comprising:

a nonvolatile memory;

a memory controller configured to control storing of data into the nonvolatile memory;

a seed generator circuit configured to:

generate first random number sequence data by performing a first XorShift operation on storage location data indicating a storage location of the data in the nonvolatile memory; and

generate a seed by using the first random number sequence data; and

a random number generator circuit configured to:

generate second random number sequence data by performing a second XorShift operation on the seed.

14. The semiconductor storage device according to claim 13 , wherein

the memory controller is configured to store the data at the storage location in the nonvolatile memory designated by a page number, and

the storage location data contains the page number, or the page number and a frame number contained in the page number.

15. The semiconductor storage device according to claim 13 , wherein

the memory controller includes the seed generator circuit and the random number generator circuit.

16. The semiconductor storage device according to claim 13 , wherein

the memory controller is configured to:

randomize user data using the second random number sequence data and;

store the randomized user data as the data at the storage location in the nonvolatile memory.