Patent ID: 12217022

The drawings are shown for illustrative purposes only.

DETAILED DESCRIPTION

The present disclosure is directed at quantum random number generators (QRNG) in which the quantum randomness of timing of quantum events is used to generate the random numbers. Systems of certain aspects of the invention generate a random number directly from the observation and recording of the occurrence/timing of a quantum random event. The system uses events that occur randomly in time at the quantum level to directly generate random numbers by sequentially converting the random timing of the events to numbers.

With reference toFIG.1, a system10in accordance with an aspect of the present invention includes a quantum event generator source12that is a source of a random or probabilistic quantum event. Examples events might be radioactive decay, a quantum electrodynamic event, etc. For example, Radium emits 36,000 alpha particles/sec./microgram. Thorium emits 4500 alpha particles/sec./gram. An event detector14detects the random quantum event. Examples of such as detector may include a scintillator or a single photon counting module. The output of the quantum event detector is provided to a computer processing system16that includes a timing system18that include a clock/timer loop20and a number converter/recorder22. As soon as an event is detected, the clock/timer loop20latches to a contemporaneous count in the continuous loop. An example may be a picosecond clock, which counts time in trillionths of a second. The loop, for example, may count 0-9 to yield a base 10 number. The number converter/recorder22, which may be a software program running on the computer processor, outputs the count number 0-9. The ten numerals (e.g., n0, n1, n2, n3, n4, n5, n6, n7, n8, n9) in the base-10 system would repeat indefinitely and continuously. This number is captured at a capture input port24, optionally stored in a memory26and provided as an output random number at28(including any number of digits) of a number sub-processing routine30. For multiple digit numbers, the system will store each generated digit until all digits are available and the result may be provided as the multi-digit output random number at output28of the number sub-processing routine30. Each digit of the output random number may be obtained from each output of a count number (e.g., 0-9).

The output may be streamed, and the memory may include any of RAM, ROM or any non-transitory stable digital media. In accordance with various further aspects, the output may further provide unparsed random numbers or other information representations for a variety of applications. In fact, the output random number may not even be a number per se but rather may be a string of bits or other units of variable information. The output random number28may for example be used by a subsequent computer processing system84including a key generator80and a secured computer82. The key generator80may be used to generate a secure key for the secured computer82. Because the output random number was not developed based on any predictable or discoverable algorithm, the key cannot be determined. Such an improved secured computer processing system has myriad applications for example in finance, government and the military.

The random event generator12releases a particle/photon, etc. The detector14detects the event, and the timer20is noted at the precise time of detection of the event. The precise time is recorded as a number22. The output of the recording is streamed to the processor30and recorded in memory26. The process is repeated creating a sequence of numbers directly corresponding (1:1) with the random events.

The sequence of numbers recorded from the events may be in any base number system and the numbers are unparsed at the time of recording. The sequence is further processed and only the last digit of the recorded time is retained. This produces a sequence of random numbers with a 1:1 equivalency to the entropy of the timing of the events recorded. For example, in the base ten, the numbers from which the sequence would be available would be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9. The clock must measure time one order magnitude faster than the high mean frequency of the event being measured. This ensures the selection would be truly random. For example, if the system is operating in base ten and the events have a high mean frequency of one event every millionth of a second, the clock must measure in a billionth of a second. Faster clocks are permissible but offer no benefit. In accordance with various aspects, the generated number may be a base n number where n is not ten, such as base two, eight or sixteen etc.

The event generator could be attenuated to reduce the frequency of particles/photons reaching the sensors. Further, from an engineering perspective, sensors require some recovery time after detection (reset) before being available to detect the next event. This probably has no effect on the system. While it would rule out the detection of random events occurring nearly simultaneously, over time missing one or more random events should have no impact on the total entropy or randomness of the aggregate collection of random events.

The variance of the random event (radioactive decay, for example) only has to occur within the window of the time available from the average frequency of the event and the window of opportunity of time offered by the clock—or one order of magnitude. For example, if the event occurs within a millionth of a second, the clock must measure to a frequency of a ten millionth of a second or greater for base ten numeral generation. For further applications, the sequence of random numbers may be parsed by the user in any manner selected by the user. The user may wish to parse the sequence, for example, to fit a particular bit structure for encryption key length or lottery numbers, etc.

In accordance with various aspects of the present invention, the method is agnostic as to the quantum phenomenon utilized. Instead of capturing a variable, such as an energy state, the present invention utilizes the quantum randomness of the timing of the event to generate a random number in a novel manner. For example, in one possible application, a source of radioactive decay such as Americium or Thorium might be utilized as a source of randomly emitted alpha particles.

The quantum event generator source12may be a source of entropy, which is a quantum process that is inherently random and probabilistic, making it an ideal choice for generating unpredictable random numbers. The source12may, for example, be a quantum entropy chip (QEC) that has radioactive decay as its source of randomness. Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by spontaneous emission (without any excitation from outside) of particles and radiation to form a stable product. A material containing unstable nuclei is considered radioactive. QEC exploits the emitted alpha particles resulting from the decay of a radioactive isotope.

FIG.2shows a functional component diagram of a quantum entropy chip32(e.g., a non-deterministic random bit generator (NRBG)), including a radioactive isotope34, a PIN diode36, an amplifier38and a sensor40. The alpha particle is actually the nucleus of a helium-4 atom24He, and consists of two protons and two neutrons, i.e., with two positive charges. Alpha decay occurs when a heavy unstable (because of the excess of nucleons) atomic nuclei dissipate excess energy by spontaneously ejecting an alpha particle. The system may be used as a quantum source (12inFIG.1) and the sensor40may provide the quantum event detector (14inFIG.1) to the computer processing system16ofFIG.1.

QEC consists of a radioactive isotope (Am-241) that emits alpha particles as a result of its decay, CMOS-type photo diode (for the detection of emitted alpha particles), two trans-impedance amplifiers (TIAs) (to amplify and detect low levels of the light current by the absorption of an alpha particle) and a comparator (to transform the amplified voltage from TIAs to an analog pulse signal, called a quantum random pulse). The energy level of the alpha particle emitted by the Americium-241 used in the QEC is 4 MeV and its radioactivity level is 4.07 kobo. The chip has a size of 3 mm×3 mm×0.85 mm with a power consumption of 3 mW. It generates random analog pulse when an alpha particle from the radioactive decay is detected which is then digitized and fed into time-to-digital converter. The output is processed by the randomness extraction module to generate raw random bits. The alpha decay of Americium-241 can be expressed as:
Am+4He  (1)
where, the numbers in subscript and superscript in the above reaction represent the atomic number and the mass number of the nucleus, respectively.

The probability of any given atom to decay in a time interval (t, t+dt) is given by a negative exponential random variable. This is shown graphically at42inFIG.3where two different consecutive timings (t12, t23) are shown. The probability may be expressed as follows:
p(t)dt=λe−λtdt(2)
where, λ is the decay constant of the radioactive material. Under the condition that, the amount of decaying atomic nuclei is large enough to be considered as constant during the measurement time and the half-life of the isotope is large enough so that the decay constant λ does not change, the time between consecutive decay events is also an exponential random variable.

One significant aspect of the exponential distribution is its memory-less property (also called Markov property). It states that the distribution of the time interval between two successive event points is the same as the distribution of the time interval between an arbitrarily chosen point, and the next event point. The time intervals are independent of previous results, i.e., the decay pulses arrive at independent times and the number of pulses that arrive in a fixed time period follows a Poisson distribution.

The probability of registering k impulses within the interval Δt is:

p⁡(k)=(Δ⁢t)kk!·e-λΔ⁢t(3)
As noted, QEC produces random pulses when these emitted alpha particles are detected by the sensor. The length of the time interval between two consecutive alpha decay pulses is unpredictable and this fact can be utilized to generate true random numbers.

Another possible source of quantum behavior (of many) would be an atom that releases an electron when stimulated, the photoelectric effect. The photoelectric effect being a, phenomenon in which electrically charged particles are released from or within a material when it absorbs electromagnetic radiation, is also suitable for use in the present invention in certain applications. The effect is often defined as the ejection of electrons from a metal plate when light falls on it. In a broader definition, the radiant energy may be infrared, visible, or ultraviolet light, X-rays, or gamma rays; the material may be a solid, liquid, or gas; and the released particles may be ions (electrically charged atoms or molecules) as well as electrons.

The precise timing of these events is utilized in certain applications of the invention as a source for the generation of randomness that is converted to a numerical representation. The number system into which the random behavior is converted into a number is not significant. A sensor, such as a scintillator or photon detector senses the quantum event and the time is precisely noted.

The quantum event detector14may be a photon detector that counts photons of light. A photon detector has a surface that absorbs photons and produces some effect (e.g., current, voltage) proportional to the number of photons absorbed.FIG.4shows a photon detector for use in certain applications of the present invention, showing incoming light44on a thin metal electrode46. A current is produced and captured by a current capture device48as current is generated as light is absorbed by the semiconductor film52. In particular, the device acts as a photovoltaic cell that consists of the layer of semiconductor (like selenium, Hg—Cd—Te, Cu2O, etc.) sandwiched between two metallic electrodes52,46, with the exposed electrode46thin enough to be transparent. Photons of light are absorbed by the semiconductor film52, forming electrons and holes that create a current proportional to the number of photons absorbed.FIG.5shows a photoelectrode cathode54that emits electron emission toward a wire anode56responsive to incoming light with the current being captured at58. These systems may each be used as a quantum source (12inFIG.1) and the current capturing device (e.g.,48,58) may provide the quantum event detector (14inFIG.1) to the computer processing system16ofFIG.1.

The times of absorption of photons are then associated with a clock sequence, using for example a time-to-digital converter, which is the fast clock, such as the pico-clock example. Instead of following a traditional or conventional route of using the generated randomness of the radioactive decay (or other such random event) as a seed for generation of a random number by some other process, such as an PRNG algorithm, the system departs completely from the standard convention.

Again. one example might be the use of a pico-clock. The pico-clock measures time in trillionths of a second. Instead of sequentially numbering the trillion ticks per second, this system numbers them according to the digits in any number base system. For example: in a base-10 system the ticks would be numbered 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 . . . etc. The ten numerals in the base-10 system would repeat indefinitely and continuously.

Alternatively, the clock could start generating any number and count up sequentially. By capturing only the last digit of the generated number, the same outcome is achieved. Assume that a quantum event occurs as set out above. That event would be detected and noted at a precise time as set forth above and a number generated. The number generated would have a one-to-one relationship to the entropy or randomness of the initiating quantum event. This is step does not require any intermediary steps to provide a random digit.

Further, the digit generated is one in a potentially endless sequence of such digits. There is no parsing of the sequence required or prohibited. The sequence itself is a continuous stream of random digits (in any number base) that is tied directly to the random quantum event.

The random quality of the quantum event is its lack of predictability and inherent probabilistic nature in time. The nature of the clock in terms of the n ticks/per unit of time has no impact on the random nature of the output, only on the volume of the digits in the sequence. There is no relationship between the indeterminant frequency of the quantum event and the ticks per unit of time of the clock.

In accordance with further aspects, the quantum random event may be generated using a modified cathode ray emitter.FIG.6Ashows a quantum random event system60that includes modified vacuum tube. The vacuum tube includes a housing62made from a non-metallic substance, input leads64, output leads66, and pairs of vertical and horizontal rotational electromagnets68.FIG.6Bshows the system60without the housing62, showing the cathode70, two opposing pairs of plates of the focusing and accelerating anode72, an electron diffraction grating76, and a two dimensional matrix sensor array78. A very high voltage is applied to the input leads64, causing the cathode70to emit electrons. The focusing and accelerating anode72has an equally high opposite potential to the cathode, causing the emitted electrons to accelerate and form a beam, and the width of the beam may be adjusted by varying the voltage across the focusing and accelerating anode72.

The pairs of vertical and horizontal rotational electromagnets68are provide after the focusing and accelerating anode72, and include four toroid electromagnets on the outside of the vacuum tube as shown. The magnets are each provided in the form of a toroid in order that their field orientation may be varied at will and at speed, without any moving parts. For example, a controller100may be used to continuously and independently vary currents to any of the electromagnetics68with respect to any of amplitude, frequency, phase etc. The vertical and horizontal rotational electromagnets68are arranged two opposite one another on a cord at the center of the X-Axis of the vacuum tube and two opposite each other on a cord at the center of the Y-Axis of the vacuum tube. Their field orientation is constantly rotating at high speed in the opposite direction to the magnet opposite (in each pair). This causes a heavy magnetic turbulence in the path of the electrons.

Electrons emitted from the cathode70and accelerated via the anode72, pass through the turbulent magnetic field resulting in the electrons having a random velocity and speed when they hit the diffraction grating76. This will create a quantum randomness of position and velocity and make the electrons impact truly random. The matrix addressed detector78, will detect the electrons that impact upon it and produce a random number based upon the position and time in the matrix where the electron impacts. The electrons are small enough and the magnetic field is turbulent enough to create randomness, and the diffraction grating76will cause electron interference which is an additional quantum effect. The system may be used as a quantum source (12inFIG.1) and the detector78may provide the quantum event detector (14inFIG.1) to the computer processing system16ofFIG.1. This quantum source may produce very large quantities of quantum behavior based random numbers when used with the clock timer/loop and number converter/recorder of aspects of the present invention.

The random number generators disclosed herein may be used in a variety of applications. For example, in one application they may be used as an embedded component in device authentication and security. Random numbers are the foundation on which all of cryptography is built. The difficulty of acquiring sufficient entropy is a common security weakness particularly with the potential emergence of quantum computers. The QRNGs described herein are able to meet and defeat this emerging threat. Particularly when combined with other emerging network security technologies. They are able to produce an output stream with an extremely high entropy at a high speed, and some embodiments may also be constructed cheaply, using off-the-shelf components at low cost.

Random number generators disclosed herein may also be used for example with lottery systems. Lotteries require a continues stream of truly random lottery number of any size or quantity can be easily generated with this methodology. Random number generators disclosed herein may further be used for example in applications requiring cryptographic random key generators. Random numbers of any size, number base can be generated using this methodology. Since these numbers are not rooted in any algorithm, they are not subject to deconstruction using a computer, regardless of the power of the computer. Even the potential of a quantum computer would offer no advantage in decrypting or deciphering the key based on the randomness of this methodology.

Those skilled in the art will appreciate that numerous modifications and variations may be made to the above disclosed embodiments without departing from the spirit and scope of the present invention.