The SwiftRNG Zn is a USB device that uses the quantum-tunneling (Zener breakdown) effect in Zener diodes to generate true random numbers at 80 Mbps. Because its noise source is physically different from the avalanche breakdown used in the other SwiftRNG models, it is a good choice for adding diversity to an entropy pool. It can be used alongside the SwiftRNG Pro, the SwiftRNG, and the SwiftRNG LE. The device was launched in 2019 as the SwiftRNG Z.

How it works

The SwiftRNG Zn generates random numbers from the electrical noise produced by Zener breakdown, a quantum-tunneling effect, in two independent noise sources. Each source uses a Zener diode with a negative temperature coefficient operating at a breakdown voltage of approximately 5.6 V. The noise from each source is amplified, filtered, and converted into digital values. The random bytes from both sources are then combined and processed on the device with a Linear Corrector using a 0.5 compression rate (P. Lacharme, “Post-Processing Functions for a Biased Physical Random Number Generator”, FSE 2008, LNCS vol. 5086, pp. 334-342, Springer-Verlag, 2008).

Quality checking

The SwiftRNG Zn implements an embedded health check test (HCT) that continuously monitors the quality of the random noise sources immediately after the electrical noise is digitized and before any further processing. The HCT logic appends a health check status byte to each transmitted data packet, so the host computer is continuously informed of the health of the generator. The SwiftRNG Zn can also run internal diagnostics on demand, triggered through the software API or the device API.

The software kit continuously runs the Repetition Count and Adaptive Proportion tests (NIST SP 800-90B) on the host computer to verify the quality of the random bytes retrieved over USB.

The SwiftRNG Zn contains patented technology.

Tech specs

More tech specs Data sheet

True random byte download speed 80 Mbps over a USB 2.0 high-speed interface
Power consumption No more than 180 mA in active mode and 90 mA when inactive
Weight 22 grams (0.77 oz)
Data connectivity and control interface USB 2.0 high-speed interface with EMI filtering (also works on full-speed ports)
Random noise source Two independent circuits based on the Zener breakdown (quantum-tunneling) effect in reverse-biased Zener diodes
Device security Secure boot from an encrypted firmware image; device access and debugging disabled
Embedded correction algorithm Linear Corrector (P. Lacharme) with a 0.5 compression rate
Embedded health check test (HCT) Continuous health diagnostics of both random noise sources
Implemented statistical tests Continuous Repetition Count and Adaptive Proportion tests in the software kit
Power supply USB bus powered
Compliance Certified for FCC (Class B), ISED (Class B), and CE compliance; RoHS compliant. See the compliance page for details
Country of origin Designed and assembled in the USA

Use cases

The SwiftRNG Zn is suited to:

  • Generation of encryption and secure session keys
  • Feeding the /dev/random entropy pool
  • Adding a physically distinct noise source to an entropy pool
  • Research (statistical sampling)
  • Computer simulations
  • Gaming servers

Statistical tests

The SwiftRNG Zn passes the following statistical test suites: Diehard, Dieharder, NIST, Rngtest, Ent, PractRand, Crush, and BigCrush.

You can download sample test reports using the links below:

System requirements

One of the following operating systems:

  • Linux (x86, x64, ARM)
  • FreeBSD 12/13/14
  • macOS (Intel and Apple Silicon)
  • Windows 10/11 (64-bit) and Windows Server 2016/2019 (64-bit)

A USB 2.0 or 3.0 high-speed host port or hub is required.

Virtual machine compatibility

SwiftRNG Zn V3.1 and later devices have been tested with the following virtual machine software:

  • VMware ESXi 6.7.0
  • VMware Workstation 15 Player
  • Oracle VirtualBox 6.1/7.0
  • Parallels Desktop for Mac (Intel and ARM)

Warranty and returns

TectroLabs offers a one-year limited warranty within the United States covering defects in materials and workmanship; we will repair or replace, at our discretion, any device that fails because of such a defect. For international orders, warranty coverage is provided in accordance with applicable local laws and regulations.

A SwiftRNG Zn may be returned within 30 days of purchase for a full refund minus the credit card processing fee. The buyer pays for return shipping.