PureQuantum® Model PQ4000KSI

The PQ4000KSI (I for internal version) is intended to be mounted within the computer enclosure if additional physical security is required. Power is provided through the motherboard USB connector.

  • 4 Megabit per second
  • Windows 32/64 bit • Linux
  • USB 2.0 Full-Speed Interface
  • Designed to meet NIST SP 800-90 B Recommendations
  • GUARANTEED to Pass ANY Properly Designed Test for Randomness!

**Note: PC expansion slot cover plate not included.

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  • Internal motherboard USB connection
  • Continuous hardware runtime testing with automatic halt
  • Raw data streams and internal statistics available
  • Independent power regulation for generator circuitry
  • ActiveX connectivity
  • Includes Drivers, interface and testing software
  • Client software forward compatible from J1000KU and R2000KU


  • For applications requiring additional physical security and smallest size
  • Gaming
  • Lotteries
  • Random Drawings
  • Cryptography
  • Data Security
  • Research


  • 4 Megabit per second ± 0.005%
  • 1/0 bias and autocorrelation < 1 part per trillion
  • Estimated quantum entropy: 0.999+ bits per output bit
  • Estimated total entropy: (1 – ε) bits per bit, ε < 10-100
  • USB 2.0 Full-Speed interface
  • Bus powered: 90mA max from internal motherboard USB connection
  • Non-condensing humidity
  • Operating temperature: 0-50 Deg. C
  • Dimensions (L x W x H): 63.5 x 50 x 6 mm

System Requirements

  • 32/64-bit Windows 7/2012/8/10/2016
  • Linux
  • USB 2.0 Full-Speed host/hub


Minimum OS required is Windows 7 or Linux 2.6


ComScire QNG Model PQ4000KSI Datasheet

PQ4000KSI Functional Description

Quantum Entropy Source Plus Hardware Runtime Testing Yield Maximum Reliability and Security

Every true random number generator (TRNG) requires a physical source of entropy. Entropy is in general a measure of disorder in a physical system. In terms of Information Theory, entropy can be thought of as a measure of how unpredictable the measured properties of the entropy source are. A simple analogy is the flip of a coin. If each flip is entirely unpredictable, that is, each flip has exactly a 50/50 chance of landing on heads (a “fair” coin), the entropy is 1.0. In the opposite extreme, if a coin had two heads, every flip of that coin would be completely predictable and the entropy would be 0.0. Quantum entropy sources may be sampled to produce what are considered the most fundamentally unpredictable random numbers possible.

The quantum entropy source in the QNG Model PQ4000KS is shot noise due to sub-threshold leakage and gate tunneling leakage in MOS transistors. In addition, sources of chaotic entropy include a combination of thermal or Johnson noise, other types of transistor noise and switching noise. Twenty-four independent, high frequency oscillating signal sources, each producing a predetermined amount of quantum entropy and chaotic entropy, continuously operate at different frequencies between 200 and 400 MHz. Each oscillator is sampled at multiple taps to produce enhanced outputs (Level one output) and the enhanced outputs are further combined to produce noisy output signals (Level two output). Seventy-five of these noisy signals are combined to produce a single sampled binary signal at 128 Mbps (Level three output).

The PQ4000KS contains three independent generators of the type described above. The statistics of each of these three generators is continuously monitored in the generator hardware. The monitoring includes 1/0 bias, 1st order autocorrelation and an estimated minimum entropy. The outputs of the three generators are combined to produce one data stream at 128 Mbps, and finally blocks of 32 non-overlapping consecutive bits are XORed together to produce each final output bit at 4 Mbps. The internal hardware monitoring requires at least two of the three generators to have an estimated entropy of at least 0.999 bits/bit. If this requirement fails, the output from the generator is automatically halted. Output bits are also tested for entropy, and the generator will be halted if the output estimated entropy falls below 0.999 bits/bit. The internal hardware testing also acts as a startup test program. At startup random data will not be output until a block of 1,048,576 bits (220 bits) from at least two of the three redundant generators has produced the required minimum estimated entropy level. In addition to the continuous testing, three sources each of Level one and Level two output, and all Level three output raw data streams are made available offline for direct statistical testing.

Interface software in the host computer monitors the flow of data from the generator. If the monitoring program detects a halt condition, a request for the internal statistics from the raw data streams will be automatically generated. These statistics are checked to determine if there has been an actual fault in the hardware, and if this check indicates a fault, an error message will be generated and no random data will be provided. The automatic check of the hardware may also indicate there was simply a delay caused by normal functioning in the computer’s operating system, programs or other attached components. If the check shows the hardware is operating correctly, the monitoring software will restart the generator output and random data flow will resume. The internal statistical test results are accessible at any time through simple commands in the user interface.

Quantum entropy of each output bit is estimated at 0.999+ bits per bit. Total quantum and chaotic entropy is indistinguishable from 1.0 and far surpasses the NIST recommendation for full entropy without any randomness correction or conditioning. Statistical defects in the final output random stream are immeasurably small.

The PQ4000KSI (I for internal version) is intended to be mounted within the computer enclosure if additional physical security is required. Power is provided through the motherboard USB connector. Independent regulation of power for the generator section prevents any external effect on the random number generation by fluctuations in the power source.

The PQ4000KS is used for cryptographic purposes as well as online gaming and other applications requiring the highest levels of security and randomness properties. The PQ4000KS has been tested extensively using well-known test suites such as DIEHARD and NIST 800-22. In addition, each generator is continuously tested by our QNGmeter test suite to 100 billion bits or more to verify compliance with our internal specifications, which are generally more stringent than either DIEHARD or NIST testing can confirm.

The generator output bits are transferred at a rate of 4 Mbps via USB interface to the PQ4000KS driver in your computer. These bits are made available to your programs by ActiveX communications in a number of different formats including 32-bit integers, 48-bit [0, 1) uniformly distributed fractions and mean = 0.0, standard deviation = 1.0 Gaussian variates[1] of maximum ±8.0 SD.

The random generation method used in the PQ4000KS[2] is highly resistant to failure due to long-term aging effects and is tolerant to expected variations in components from different production runs. The high level of redundancy provided by the three independent generators and the large number of entropic bits used to produce each output bit ensures consistent and highest quality true random numbers for any application[3].

[1]. Gaussian (Normally distributed) variates are calculated from pairs of uniformly distributed random variates using the Box-Muller transform.

[2]. Patent pending.

[3]. The PQ4000KS is protected under US patent numbers 6,763,364, 6,862,605, 7,096,242 and 7,752,247; other patent(s) pending.