Optical key protected authentication and encryption

1. An apparatus for authenticating an optical key by verifying a match of a challenge-response pair, comprising:

a challenge forming device that forms a challenge;

an optical key comprising scattering material, the optical key is receptive to the challenge and provides a response to the challenge; and

a response verifying device that is receptive to the response provided by the optical key, the response verifying device verifying if the response provided by the optical key matches the challenge,

wherein the optical key is, when or after being exposed to an external influence comprising a physical or chemical stimulus, reliably authenticated, and

wherein the physical or chemical stimulus is a mechanical stress or chemical contact.

2. The apparatus of claim 1 , wherein the optical key is reliably authenticated at more than one temperature.

3. The apparatus of claim 1 , wherein the optical key is reliably authenticated after exposure to touching or clothing or weather.

4. An apparatus for authenticating an optical key by verifying a match of a challenge-response pair, comprising:

a challenge forming device that forms a challenge;

an optical key comprising scattering material, the optical key is receptive to the challenge and provides a response to the challenge; and

a response verifying device that is receptive to the response provided by the optical key, the response verifying device verifying if the response provided by the optical key matches the challenge,

wherein the optical key is, when or after being exposed to an external influence comprising a physical or chemical stimulus, reliably authenticated, and

wherein the optical key has a thermal reliability parameter lower than 1/(200,000 Kelvin), the thermal reliability parameter being an absolute value of one or more summed up temperature coefficients of the optical key.

5. The apparatus of claim 4 , wherein the one or more summed up temperature coefficients of the optical key comprise a temperature coefficient of an optical path length (1/S)(dS/dT).

6. The apparatus of claim 4 , wherein the one or more summed up temperature coefficients are selected from the group consisting of a temperature coefficient of a length of the optical key, a temperature coefficient of an area of the optical key, a temperature coefficient of a volume of the optical key, and a temperature coefficient of a refractive index of the optical key.

7. The apparatus of claim 4 , wherein the optical key comprises at least two different materials and the thermal reliability parameter of each material is lower than 1/(100,000 Kelvin).

8. The apparatus of claim 1 , wherein the optical key comprises a ceramic material with at least two different phases, wherein at least one of the two different phases defines a structure that determines the response of the optical key when receiving the challenge.

9. The apparatus of claim 8 , wherein the ceramic material is a glass ceramic.

10. An apparatus for authenticating an optical key by verifying a match of a challenge-response pair, comprising:

a challenge forming device that forms a challenge;

an optical key comprising scattering material, the optical key is receptive to the challenge and provides a response to the challenge; and

a response verifying device that is receptive to the response provided by the optical key, the response verifying device verifying if the response provided by the optical key matches the challenge,

wherein the optical key is, when or after being exposed to an external influence comprising a physical or chemical stimulus, reliably authenticated, and

wherein the optical key comprises a material selected from the group consisting of cordierite; silimanit; cristobalite; Mg—B quartz; mullit; eucryptite; AB 2 O 8 where A is selected from the group consisting of Zr, Hf, Zn, Ti, U, TH, Lu, or mixtures thereof and B is selected from the group consisting of W, Mo, or mixtures thereof; CD 2 O 7 where C is selected from the group of consisting of Zr, Hf, Zn, Ti, U, TH, Lu, Pu, Np, W, Ce, Sn, Ge, Si, or mixtures thereof and D is selected from the group of elements consisting of V,P, or mixtures thereof; E 2 F 3 O 12 where E is selected from the group of consisting of Sc, Y, Lu, Al, Ga, La, Lanthanoids, or mixtures thereof and F is selected from the group consisting of W, Mo, and P; and GH 3 where G is selected from the group consisting of Sc, Y, Ba, Mg, Ca, and Sr and H is selected from the group consisting of F, Cl, and mixtures thereof.

11. The apparatus according to claim 1 , wherein the optical key comprises a material with a tuned scattering property.

12. The apparatus according to claim 11 , wherein the tuned scattering property is a tuned scattering length of at least 1 and at most 10 micrometer.

13. The apparatus according to claim 11 , whereat the optical key comprises a physical unclonable function that prevents manufacture of a replica of the optical key.

14. The apparatus of claim 1 , further comprising a fixture for temporal fixation of the optical key when receiving the challenge formed by the challenge forming device.

15. The apparatus of claim 1 , further comprising an interpolation device for interpolating between multiple responses of the optical key obtained at different temperatures.

16. A method for authenticating an optical key by verifying a match of a challenge-response pair, comprising:

forming a challenge using a challenge forming device;

providing a response to the challenge via an optical key receptive to the challenge; and

verifying if the response provided by the optical key matches the challenge via a response verifying device that is receptive to the response provided by the optical key,

wherein the optical key is, when or after being exposed to an external influence comprising a physical or chemical stimulus, reliably authenticated, and

wherein the physical or chemical stimulus is a mechanical stress or chemical contact.