QuantumVillage Releases $35 Open Source Quantum Random Number Generator

QuantumVillage is challenging the cost of quantum technology with the release of the “Entropy Loop,” a fully functional Quantum Random Number Generator available for $35. Released on April 14, 2026, coinciding with World Quantum Day, the device utilizes readily accessible components, fiber optics and a Raspberry Pi Pico, to generate truly random numbers based on quantum fluctuations. The company states that the best way to democratize this technology is to open source a minimal viable example, aiming to broaden access to quantum entropy for applications ranging from artificial intelligence to cryptography.

The Entropy Loop, packaged in a credit-card sized format, represents a step toward making quantum randomness a fundamental resource for a wider range of developers and researchers. Phase-Diffusion QRNG Utilizing Pulsed Laser Diode This significantly reduces the cost of conventional quantum technology implementations and signals a shift toward wider accessibility of this powerful technology. The core principle behind the Entropy Loop relies on the inherent randomness of quantum fluctuations within a pulsed laser diode. When the laser diode is powered on and off, quantum fluctuations dictate its current phase and polarization, creating unique properties with each pulse. These pulses are then directed into a fiber optic network, where approximately 50 percent travel directly to a detector while the remainder is routed through a five-meter photonic delay line. Project documentation explains that each of these pulses have different phase and polarization properties, and their random interactions are fundamentally chaotic, detailing how this interaction generates the desired randomness. The five-meter delay ensures the traveling pulse interacts with the subsequent pulse from the laser, amplifying the effect of the quantum fluctuations. This approach, detailed in the paper Ultra-fast quantum randomness generation by accelerated phase diffusion in a pulsed laser diode by Abellán et al., allows for a compact and affordable QRNG. The system’s software, available in C and MicroPython, is orchestrated across the Raspberry Pi Pico’s cores. Core 0 handles data acquisition from the receiver via the ADC, while Core 1 manages min-entropy calculation and UART communication over USB. The Pico is overclocked to 250MHz, enabling a pulse frequency of up to 125MHz, though the system operates at a lower rate, a 4-nanosecond pulse followed by a 20-nanosecond rest, to guarantee complete desaturation of the laser diode and maximize the utilization of vacuum fluctuations. A lagged look-around analysis is employed to generate a histogram of delta difference values, normalizing the calculation and mitigating potential biases from the pulsed nature of the randomness. The documentation states that given a window of 1024 samples, the maximum value for min-entropy is theoretically limited by the window size. The complete bill of materials includes fiber splitters, a fiber patch cable, SC/APC fiber connectors, the Raspberry Pi Pico, a prototyping board, resistors, and a capacitor, all contributing to the remarkably low price point.

Raspberry Pi Pico Implementation with PIO & ADC The proliferation of quantum random number generators has historically been hampered by cost and complexity, requiring specialized hardware and expertise beyond the reach of many researchers and hobbyists. However, QuantumVillage’s Entropy Loop demonstrates a departure from this norm, leveraging the accessibility of readily available components to deliver a functional QRNG at a price of $35. This achievement is not simply about affordability; it’s a deliberate strategy to “democratize this technology,” according to the company, and provide a fully working bill of materials with firmware that passes all major entropy quality tests. Central to the Entropy Loop’s design is the Raspberry Pi Pico microcontroller, utilized in conjunction with fiber optics to harness quantum fluctuations. The system exploits the inherent randomness arising from the powering sequence of a laser diode. Project documentation explains that when a laser diode powers up, quantum fluctuations occur that determine the laser’s current phase and polarization during operation. These fluctuations are then channeled through a five-meter fiber optic delay line, creating a chaotic interaction between successive laser pulses.

The Pi Pico’s Programmable I/O (PIO) peripheral is crucial, managing the precise timing of the laser pulses, a 4 nanosecond on-time followed by a 20 nanosecond rest, to ensure proper desaturation and maximize the effect of the vacuum fluctuations. Data acquisition relies on the Pico’s Analog-to-Digital Converter (ADC), reading signals biased at 1.65V, centered within the 3.3V range. The 12-bit ADC collects data in 1024-value windows, which are then processed by core 1 of the Pi Pico. The entire system, including optical components, splitters, and connectors, is designed for ease of assembly, with detailed build instructions and a complete bill of materials available. Entropy is fast becoming a fundamental resource, especially as AI, simulations, optimizers, cryptography, and computing in general are all changing and accelerating in reach and usefulness. Min-Entropy Calculation via Lagged Derivative Analysis QuantumVillage’s approach to generating verifiable randomness isn’t reliant on complex, large-scale quantum computers, but rather a surprisingly accessible method of analyzing laser diode behavior. The core of their Entropy Loop system, detailed in the project’s publicly available code repository, centers on a sophisticated min-entropy calculation performed using a technique called lagged derivative analysis. This process moves beyond simply measuring quantum fluctuations; it actively processes the data to ensure a robust and reliable source of randomness.

The team recognized that raw measurements, while quantum in origin, could be skewed by the system’s characteristics, necessitating a normalization step. After acquiring data from the photodetector, the code focuses on calculating “delta” values, the difference between successive measurements, but with a twist. The lagged derivative calculation aims to flatten the distribution of these delta values, preventing incidental peaks that might falsely inflate entropy estimates. This normalization is achieved by adding 2048 to center the result, and then calculating the delta against the historical value from the buffer. The code then updates a histogram, incrementing counts for each delta value, with a safeguard: “if(counts[delta] max_count) { max_count = counts[delta]; }”. This prevents a single delta value from dominating the histogram and skewing the final min-entropy calculation. Ultimately, min-entropy is calculated as “10.0f – log2f((float)max_count);”, then scaled to an 8-bit representation. This meticulous process, performed on a device costing just $35, demonstrates a powerful method for extracting high-quality randomness from readily available components, and is a key factor in making quantum technology more accessible. We believe the best way to democratize this technology is to open source a ‘strong minimal viable example’, as we did with quantum sensing, and provide a fully working off the shelf BOM with firmware that passes all major entropy quality tests.

Entropy Loop Hardware: Bill of Materials & Assembly While quantum systems traditionally demand substantial investment, this device demonstrates a pathway to democratization through the clever utilization of readily available components. The core of the Entropy Loop’s affordability lies in its bill of materials. Rather than relying on specialized, custom-built hardware, the system is constructed around a Raspberry Pi Pico and standard fiber optics. A crucial component is a five-meter length of fiber used as a photonic delay line, alongside two fiber splitters. These optical elements, coupled with inexpensive electronic components like resistors and capacitors, contribute to the remarkably low cost. The complete build requires a pair of fiber optic transceivers, and a prototyping board for assembly.

The team notes that for their build, they use SC/APC fiber connector parts, usually green, highlighting the practical considerations of minimizing signal reflection with angled connectors. The choice of multimode 9/125 fiber, commonly used in data transmission, further underscores the reliance on existing infrastructure. Assembly involves connecting the laser driver to GPIO0 on the Raspberry Pi Pico, utilizing ADC0 to read data from the receiver. A small circuit normalizes the voltage to center it around 1.65V, ensuring compatibility with the Pico’s 3.3V ADC range. The system’s design incorporates a 10nF ceramic capacitor and two 10k Ohm resistors to achieve this voltage shift. The transceivers are configured to transmit and receive at different wavelengths, 1310nm and 1550nm, optimizing signal flow within the fiber loop. The build documentation details that pin 8 on the A module (TX positive pin) is used to drive the laser, providing precise instructions for replication.

The team emphasizes the importance of SC/APC connectors, noting that they have an 8 degree angle cut on the end to minimize reflections, which is ideal for their purposes. The complete bill of materials, including links to suppliers like AliExpress, is publicly available, encouraging wider adoption and experimentation. We are grateful to Eric Case and Dr. Evan Anderson for their help and contributions to validation and testing the design, as well as the Quantum Village community’s continued enthusiasm for lo-fi DIY ‘bits box’ Quantum! NIST STS 2.1.2 Validation & System Overview The pursuit of accessible quantum technology often conjures images of complex, multi-million dollar installations. However, recent validation by the National Institute of Standards and Technology (NIST) under the STS 2.1.2 standard demonstrates a surprising reality: robust quantum random number generation is now achievable with remarkably inexpensive, readily available components. QuantumVillage’s ‘Entropy Loop’ isn’t scaling down quantum computing; it’s radically altering the economics of quantum randomness, bringing it within reach of researchers, developers, and potentially even consumers. The system’s core innovation lies in harnessing quantum fluctuations within a common laser diode. This isn’t about building a quantum computer; it’s about extracting verifiable randomness from a physical process governed by quantum mechanics. The resulting signal, captured by a Raspberry Pi Pico’s analog-to-digital converter, forms the basis for a high-quality random number generator. The entire build, excluding the fiber optic cabling, boasts a bill of materials totaling just $35, a figure that dramatically undercuts the cost of traditional QRNG implementations. The software underpinning the Entropy Loop is equally accessible, available in both C and MicroPython. This careful calibration maximizes the influence of vacuum fluctuations on the generated randomness. The system employs a lagged look-around analysis to calculate min-entropy, a measure of the unpredictability of the random numbers. QuantumVillage released the Entropy Loop on April 14, 2026, signaling a commitment to democratizing access to quantum technologies and fostering wider understanding of their potential. The project’s open-source nature, coupled with its low cost and reliance on off-the-shelf components, positions it as a powerful tool for education, research, and the development of applications requiring truly random numbers, from cryptography to artificial intelligence. This is a gold-standard test suite from the NIST standardization people. Source: https://github.com/QuantumVillage/EntropyLoop Tags: