[[!meta title="ChaosKey"]]
# ChaosKey
This is a hardware True Random Number Generator that attaches via USB.
The Linux Kernel, starting with version 4.1, includes source for this
driver. It should be built by default in your distribution. If your
using Linux + KVM to host other Linux instances, read the
[VirtualMachine](VirtualMachine.html) page to see how you can configure the guests to share
the host entropy source.
## Version 1.0 ##
1.0 is the first production version of ChaosKey, now available for sale
in single units and packs of 10 and 25 units at
[Garbee and Garbee](http://shop.gag.com/random.html) and
[vikings](https://store.vikings.net/accessories/chaoskey).
### Version 1.0 Hardware ###
* [STM32F042](http://www.st.com/web/catalog/mmc/FM141/SC1169/SS1574/LN1823?icmp=stm32f0x2-line_pron_pr_jan2014&sc=stm32f0x2-pr) System-on-Chip
* ARM Cortex-M0 MCU
* 32k Flash
* 6k RAM
* USB 2.0 Full Speed
* Crystal-less operation
* 20V noise source
* AP3015A boost regulator
* back-to-back 3904 transistor noise
* [OPA356](http://www.ti.com/product/opa356) op amp
* 200MHz GBP
Here's a circuit diagram of the noise source:
### Version 1.0 Bits ###
Source code for the firmware, flash loader and a utility to pull raw
bits from the noise source are available here:
[AltOS Git Repository](http://git.gag.com/?p=fw/altos;a=summary)
[ChaosKey Firmware version 1.6.7](v1.0/chaoskey-v1.0-1.6.7.elf)
[ChaosKey Boot Loader version 1.6.7](v1.0/chaoskey-v1.0-altos-flash-1.6.7.elf)
Hardware designs using [gEDA](http://www.geda-project.org/) are
available here:
[ChaosKey Hardware Design Files](http://git.gag.com/?p=hw/chaoskey;a=summary)
## Version 0.3 ##
This one uses the better noise source coupled with an op amp that
provides 2MHz of bandwidth at a gain of 100, offering linear frequency
response at a million samples per second.
A photo of prototype version 0.3:
Here's a circuit diagram of the noise source:
Version 0.3 uses the same hardware design as version 1.0, except that
it uses a QFP package version of the processor instead of the QFN used
in 1.0, and hence needs a larger circuit board.
## Version 0.2 ##
This version uses a better noise source, but the single transistor amp
designed to get from the 20mV noise source to a digital value doesn't
provide enough bandwidth, so the resulting signal seen by the CPU has
poor frequency response.
Here's a photo of prototype version 0.2:
### Version 0.2 Hardware ###
* [STM32F042](http://www.st.com/web/catalog/mmc/FM141/SC1169/SS1574/LN1823?icmp=stm32f0x2-line_pron_pr_jan2014&sc=stm32f0x2-pr) System-on-Chip
* ARM Cortex-M0 MCU
* 32k Flash
* 6k RAM
* USB 2.0
* Crystal-less operation
* 20V noise source
* AP3015A boost regulator
* back-to-back 3904 transistor noise
## Version 0.1 ##
These are photos of prototype version 0.1:
### Version 0.1 Hardware ###
* [NXP LPC11U14](http://www.nxp.com/products/microcontrollers/cortex_m0_m0/LPC11U14FHI33.html) System-on-Chip
* ARM Cortex-M0 MCU
* 32k Flash
* 6k RAM
* USB 2.0
* 8 12-bit analog inputs
* I2C, SPI, async serial
* digital I/O
* ZXRE1004 zener diode noise source
* MCP6L92 dual op-amp
## Software ##
* Firmware Features
* [AltOS](../AltOS/) is written mostly in C with some ARM assembler
* Tools Used
* [gEDA](http://www.gpleda.org/) for schematic capture and PCB layout
* [GCC](http://gcc.gnu.org/) compiler and source debugger
* Licenses
* The hardware is licensed under the [TAPR](http://www.tapr.org) [Open Hardware License](http://www.tapr.org/ohl.html)
* The software is licensed [GPL version 2](http://www.gnu.org/licenses/old-licenses/gpl-2.0.html)