---
name: "vrng"
section: "4"
platform: "openbsd"
package: "man"
version: "8.0-current-20261101"
release: "OpenBSD 8.0-current (2026-11-01)"
platforms: ["openbsd"]
url: "https://new.carta.tech/vrng"
---

# vrng(4)

virtual random number generator

## NAME

**vrng** – virtual random number generator

## SYNOPSIS

**vrng0 at vbus?**

## DESCRIPTION

The **vrng** driver provides support for the random number generation service provided by the UltraSPARC Hypervisor as found on sun4v systems.

Driven by periodic checks for available data from the generator, **vrng** supplies entropy to the [random(4)](/random/4.md) driver for common usage.

## SEE ALSO

[intro(4)](/intro/4.md), [random(4)](/random/4.md), [vbus(4)](/vbus/4.md)

## HISTORY

The **vrng** driver first appeared in OpenBSD 4.5.

## AUTHORS

The **vrng** driver was written by Mark Kettenis ⟨*kettenis@openbsd.org*⟩.

## BUGS

The **vrng** driver should probably do periodic “health checks” when running in a Trusted Domain, but currently does not.