1. A self-authenticating, quantum random bit generator comprising:
a transmission layer including,
an electromagnetic radiation source coupled to a waveguide branching into a first waveguide, a second waveguide, and a third waveguide, the electromagnetic radiation source configured to generate pulses of electromagnetic radiation in a first polarization state;
two or more polarization rotators positioned and configured to rotate pulses transmitted in the second waveguide into a second polarization state and rotate pulses transmitted in the third waveguide into a third polarization state; and
a system control configured to generate a sequence of bits based on polarization basis states of the pulses transmitted in the first waveguide, and tomographically authenticate randomness of the sequence of bits based on polarization basis states of the pulses transmitted in the second and third waveguides.
2. The generator of claim 1 further comprises an attenuator operably coupled to the first waveguide and configured to reduce the energy of the pulses transmitted in the first waveguide to at most a single photon.
3. The generator of claim 1 further comprises a first polarizing beamsplitter coupled to the first waveguide, a second polarizing beamsplitter coupled to the second waveguide, and a third polarizing beamspitter coupled to the third waveguide.
4. The generator of claim 3 wherein the first, second, and third polarizing beamsplitters split each pulse into two polarization basis states.
5. The generator of claim 1 wherein the electromagnetic radiation source further comprises one of:
a diode laser; and
a light-emitting diode coupled to a waveguide polarizer and a polarization rotator.
6. The generator of claim 1 wherein each polarization rotator further comprise one of:
two or more polarization rotators;
a half-wave plate; and
a quarter-wave plate.
7. The generator of claim 1 wherein the system control further comprises:
a pair of avalanche photodiodes configured to detect photons transmitted in the first waveguide;
a first pair of p-i-n photodetectors configured to detect pulses transmitted in the second waveguide; and
a second pair of p-i-n photodetectors configured to detect pulses transmitted in the third waveguide.
8. The generator of claim 1 wherein the system control further comprises detectors configured to detect polarization basis states of the pulses transmitting in the first, second, and third waveguides.
9. The generator of claim 1 wherein the waveguides further comprise one of
ridge waveguides;
waveguides in a photonic crystal; and
optical fibers.
10. The generator of claim 1 wherein the transmission layer further comprises one of:
silicon oxynitride; and
an optical polymer.
11. An optoelectronic chip including the self-authenticating quantum random bit generator of claim 1 embedded within a layer of the optoelectronic chip.
12. A method for generating a sequence of random bits, the method comprising:
generating a sequence of electromagnetic radiation pulses, each pulse in a first polarization state;
splitting each pulse into a first pulse, a second pulse, and a third pulse, all three pulses in the same first polarization state;
rotating each second pulse into a second polarization state and each third pulse into a third polarization state using polarization rotators;
generating a sequence of bits based on detecting one of two polarization basis states of the first pulse; and
based on the polarization states of the second and third pulses, performing tomographic analysis in order to authenticate the randomness of the sequence of bits.
13. The method of claim 12 further comprising attenuating the first pulse intensity into a single photon.
14. The method of claim 12 further comprising splitting the first pulse into two polarization basis states, the second pulse into two polarization basis states, and the third pulse into two polarization basis states.
15. The method of claim 14 wherein splitting the pulses into two polarization basis states further comprises transmitting each pulse through a polarizing beamsplitter.
16. The method of claim 12 wherein rotating each second pulse into a second polarization state and each third pulse into a third polarization state further comprises transmitting each second pulse through one or more polarizing beamsplitters and transmitting each third pulse through one or more polarizing beamsplitters.
17. The method of claim 12 wherein generating a sequence of bits further comprises assigning a bit \u201c1\u201d to detecting one of the two polarization basis states of the first pulse and assigning a bit \u201c0\u201d to detecting the other of the two polarization basis states of the first pulse.
18. The method of claim 12 wherein performing tomographic analysis further comprises constructing the minimum entropy:
H
Min
\u2061
(
\u03c1
^
S
)
\u2261
–
log
2
(
max
x
\u2208
\u03c1
^
S
\u2062
Pr
\u2061
(
x
)
)
where
{circumflex over (\u03c1)}S is the density matrix for an ensemble of states |104 i=ci|H+di|V as a function of Stokes parameters;
Pr (x) is the probability of a event x; and
max
x
\u2208
X
\u2062
Pr
\u2061
(
x
)
means the maximum probability Pr (x) over every event x in X.
19. The method of claim 18 wherein the density matrix further comprises:
\u03c1
^
S
=
1
2
\u2062
\u2211
i
=
0
3
\u2062
S
i
S
0
\u2062
\u03c3
i
=
1
2
\u2061
1
+
S
3
S
1
–
iS
2
S
1
+
iS
2
1
–
S
3
where
(S0, S1, S2, S3) are Stokes parameters;
the Stokes parameter S0 is normalized to \u201c1\u201d; and
\u03c31, \u03c32, and \u03c33 are the Pauli matrices.
20. The method of claim 18 wherein performing tomographic analysis further comprises constructing a Toeplitz matrix Tm\xd7n based on the minimum entropy Hmin({circumflex over (\u03c1)}S), where m is the number of random bits, n is the number of raw bits, and m<n.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An electronic control system for a vehicle comprising:
a sensor that provides information relating to a steering angle of a vehicle wheel;
wherein the electronic control system uses the information provided by the sensor to determine that the measured speed that the steering angle is changing exceeds a threshold speed.