Random number generation device and vehicle control device

1. A random number generation device including a first random number generator which generates a new first random number based on a first random number which was previously generated and which outputs the new first random number generated by the first random number generator, the random number generation device comprising:

a second random number generator which generates a second random number different from the new first random number generated by the first random number generator; and

an operation module which outputs a main random number obtained by a prescribed operation using the second random number generated by the second random number generator with the new first random number generated by the first random number generator only when generating a main random number after restarting of a supply of electric power to the device.

2. The random number generation device according to claim 1 , further comprising:

a volatile memory in which a previously generated first random number generated by the first random number generator is stored only while the electric power is supplied, wherein

the first random number generator generates the new first random number based on the first random number stored in the volatile memory and stores the new first random number in the volatile memory.

3. The random number generation device according to claim 2 , further comprising:

a nonvolatile memory in which a previously generated second random number generated by the second random number generator is stored when the electric power is not supplied, wherein

the second random number generator generates a new second random number based on a the second random number stored in the nonvolatile memory using a generation method of random numbers which is different from the first random number generator.

4. The random number generation device according to claim 1 , wherein

the second random number generator generates a new second random number only when generating a random number after the restarting of supplying electric power, and stores the new second random number in the nonvolatile memory.

5. The random number generation device according to claim 4 , wherein

the second random number generator generates the new second random number using a linear congruential method based on the second random number stored in the nonvolatile memory.

6. The random number generation device according to claim 4 , further comprising:

a third random number generator which generates a third random number corresponding to a period which is necessary to store a the new second random number generated by the second random number generator into the nonvolatile memory, wherein

the operation module operates the prescribed operation using the third random number generated by the third random number generator in addition to the new second random number generated by the second random number generator.

7. A vehicle control device performing a prescribed control with respect to a vehicle based on a verify result of an identification code stored in a key carried by a user with an identification code previously registered in the vehicle, comprising:

the random number generation device according to claim 1 , in which electric power is supplied from a battery provided at the vehicle, wherein the vehicle control device encodes the identification code of the key and the identification code of the vehicle using a random number generated by the random number generation device.

8. The vehicle control device according to claim 7 , wherein

the prescribed control with respect to the vehicle is a start control of an engine, and

the random number generation device generates a first main random number in a case in which there is a first start instruction of the engine after restarting of the supply of electric power from the battery to the device.