-----BEGIN PGP SIGNED MESSAGE----- In list.cypherpunks, thus spake pfarrell@netcom.com (Pat Farrell):
A while ago some folks talked about being willing to pay for a hardware random number generator. Not a PRNG, but a real one. There are lots of uses listed in TCMay's document that can't be named, but generating blinding factors for digital cash is my favorite.
I've got a friend who is a professional electronics engineer that is willing to help, but he has some questions on the design.
[...]
3. Maybe it should go on the PC bus as an adapter card.
This is the way to go. Serial port real estate is way too scarce in the average PC. Besides, this approach makes the design easier and has another advantage...
While I'd like to think that I really control my PC, once you get networking TSRs, smartdrv, APSI drivers, CDROM and Soundcard drivers, HIMEM, etc. loaded, do you really _know_ that they are your friends? Is this a real problem?
Yes, this can be a real problem. So design the card such that the noise source runs continuously at a high speed, and feeds an 8-bit shift register. Place a latch on the output of the register, and set up decoding logic to read the latch in a memory-mapped port position. Ports are available, if you look and plan around the popular ones (such as UARTs, soundblasters, CD-ROM cards, etc.). You'll want to make it configurable to several possible ports. This design assures that each random byte can only be read once. A TSR couldn't read the card in parallel (because reading a port doesn't require hooking an interrupt), so the only way to compromise it is to subvert the application reading the card. Conventional anti-virus protection can see to it that the app remains trustworthy.
Cypherpunks write code (or maybe work on hardware :-) !
I hack both. Hardware is fun! - -- Roy M. Silvernail -- roy@sendai.cybrspc.mn.org will do just fine, thanks. "Does that not fit in with your plans?" -- Mr Wiggen, of Ironside and Malone (Monty Python) PGP 2.3a public key available upon request (send yours) -----BEGIN PGP SIGNATURE----- Version: 2.6 iQCVAwUBLgRdWxvikii9febJAQG16wP7BzcIdnQw/TPFO+E/GwnPIt3xBVu0lHq3 H1ACbdiWMxD55F2GiQ21fZ7K1IRtr8gTsgKGnbBDMMW7hjfVmFinzYJRhH/jBnQC 0nndL9bK+DtX42GyDYn88MnGYQL1b+7Efp6V1QNP+gGdfYYZrZwqscgajPalPkKD qQveABptfBI= =+j3A -----END PGP SIGNATURE-----