1 [[!meta title="ChaosKey"]]
4 This is a hardware True Random Number Generator that attaches via USB.
6 The Linux Kernel, starting with version 4.1, includes source for this
7 driver. It should be built by default in your distribution. If your
8 using Linux + KVM to host other Linux instances, read the
9 [VirtualMachine](VirtualMachine.html) page to see how you can configure the guests to share
10 the host entropy source.
14 1.0 is the first production version of ChaosKey, now available for sale
15 in single units and packs of 10 and 25 units at
16 [Garbee and Garbee](http://shop.gag.com/random.html) and
17 [vikings](https://store.vikings.net/chaoskey).
19 <a href="v1.0/chaoskey-bare.jpg"><img src="v1.0/chaoskey-bare-thumb.jpg"></a>
21 <a href="v1.0/chaoskey-boxed.jpg"><img src="v1.0/chaoskey-boxed-thumb.jpg"></a>
23 ### Reflashing Firmware ###
25 To reflash the system firmware on ChaosKey, you first need to get the
26 device into 'bootloader mode'. To do this, you must power-up ChaosKey
27 with a jumper between GND and the Boot Loader Select pin.
29 Open up ChaosKey by prying the case apart. There's no glue or screws,
30 so a thin tool or fingernail should suffice to split the case into two
31 pieces. Once you've opened it up, you'll find the inside that looks
34 <img src="chaoskey-connector.svg">
36 Connect a wire between the two red holes in the debug connector and
37 then plug it in to your computer. It will appear as a USB modem device
38 called AltosFlash with USB ID fffe:000a.
40 Use the 'ao-usbload' program, which is part of the
41 [AltOS repository](https://altusmetrum.org/AltOS/)
42 and is packaged for Debian in the 'altos' package:
44 $ ao-usbload chaoskey-v1.0-*.elf
46 ### Version 1.0 Hardware ###
48 * [STM32F042](http://www.st.com/web/catalog/mmc/FM141/SC1169/SS1574/LN1823?icmp=stm32f0x2-line_pron_pr_jan2014&sc=stm32f0x2-pr) System-on-Chip
53 * Crystal-less operation
55 * AP3015A boost regulator
56 * back-to-back 3904 transistor noise
57 * [OPA356](http://www.ti.com/product/opa356) op amp
60 Here's a circuit diagram of the noise source:
62 <img src="v1.0/noise-source.svg">
64 ### Version 1.0 Bits ###
66 Source code for the firmware, flash loader and a utility to pull raw
67 bits from the noise source are available here:
69 [AltOS Git Repository](http://git.gag.com/?p=fw/altos;a=summary)
71 [ChaosKey Firmware version 1.6.7](v1.0/chaoskey-v1.0-1.6.7.elf)
73 [ChaosKey Boot Loader version 1.6.7](v1.0/chaoskey-v1.0-altos-flash-1.6.7.elf)
75 Hardware designs using [gEDA](http://www.geda-project.org/) are
78 [ChaosKey Hardware Design Files](http://git.gag.com/?p=hw/chaoskey;a=summary)
83 This one uses the better noise source coupled with an op amp that
84 provides 2MHz of bandwidth at a gain of 100, offering linear frequency
85 response at a million samples per second.
87 A photo of prototype version 0.3:
89 <a href="v0.3/chaoskey-v0.3.jpg"> <img src="v0.3/chaoskey-v0.3-thumb.jpg"></a>
91 Here's a circuit diagram of the noise source:
93 <img src="v0.3/noise-source.svg">
95 Version 0.3 uses the same hardware design as version 1.0, except that
96 it uses a QFP package version of the processor instead of the QFN used
97 in 1.0, and hence needs a larger circuit board.
101 This version uses a better noise source, but the single transistor amp
102 designed to get from the 20mV noise source to a digital value doesn't
103 provide enough bandwidth, so the resulting signal seen by the CPU has
104 poor frequency response.
106 Here's a photo of prototype version 0.2:
108 <a href="v0.2/chaoskey-v0.2.jpg"> <img src="v0.2/chaoskey-v0.2-thumb.jpg"></a>
110 ### Version 0.2 Hardware ###
112 * [STM32F042](http://www.st.com/web/catalog/mmc/FM141/SC1169/SS1574/LN1823?icmp=stm32f0x2-line_pron_pr_jan2014&sc=stm32f0x2-pr) System-on-Chip
117 * Crystal-less operation
119 * AP3015A boost regulator
120 * back-to-back 3904 transistor noise
124 These are photos of prototype version 0.1:
126 <a href="v0.1/chaoskey-v0.1-top.jpg"> <img src="v0.1/chaoskey-v0.1-top-thumb.jpg"></a>
127 <a href="v0.1/chaoskey-v0.1-bottom.jpg"> <img src="v0.1/chaoskey-v0.1-bottom-thumb.jpg"></a>
129 ### Version 0.1 Hardware ###
131 * [NXP LPC11U14](http://www.nxp.com/products/microcontrollers/cortex_m0_m0/LPC11U14FHI33.html) System-on-Chip
136 * 8 12-bit analog inputs
137 * I2C, SPI, async serial
139 * ZXRE1004 zener diode noise source
140 * MCP6L92 dual op-amp
145 * [AltOS](../AltOS/) is written mostly in C with some ARM assembler
147 * [gEDA](http://www.gpleda.org/) for schematic capture and PCB layout
148 * [GCC](http://gcc.gnu.org/) compiler and source debugger
150 * The hardware is licensed under the [TAPR](http://www.tapr.org) [Open Hardware License](http://www.tapr.org/ohl.html)
151 * The software is licensed [GPL version 2](http://www.gnu.org/licenses/old-licenses/gpl-2.0.html)