Re: [Cryptography] Thoughts on hardware randomness sources

2013-09-14 Thread Marcus D. Leech
On 09/13/2013 11:32 PM, Jerry Leichter wrote: On Sep 12, 2013, at 11:06 PM, Marcus D. Leech wrote: There are a class of hyper-cheap USB audio dongles with very uncomplicated mixer models. A small flotilla of those might get you some fault-tolerance. My main thought on such things relates

Re: [Cryptography] Thoughts on hardware randomness sources

2013-09-13 Thread Marcus D. Leech
On 09/12/2013 10:38 PM, Thor Lancelot Simon wrote: The audio subsystem actually posed *two* obvious opportunities: amplifier noise from channels with high final stage gain but connected by a mixer to muted inputs, and clock skew between system timers and audio sample clocks. The former

Re: [Cryptography] Radioactive random numbers

2013-09-12 Thread Marcus D. Leech
On 09/11/2013 07:18 PM, Perry E. Metzger wrote: The attraction of methods that use nothing but a handful of transistors is that they can be fabricated on chip and thus have nearly zero marginal cost. The huge disadvantage is that if your opponent can convince chip manufacturers to introduce

Re: [Cryptography] Thoughts on hardware randomness sources

2013-09-10 Thread Marcus D. Leech
On 09/10/2013 12:04 PM, Rob Kendrick wrote: I wonder what people's opinions are on things like the randomsound daemon that is available for Linux. Daniel Silverstone, the author, specifically advises people to not use it. :) I haven't actually looked at the code. Conceptually, anything with an

[Cryptography] Thoughts on hardware randomness sources

2013-09-10 Thread Marcus D. Leech
I wonder what people's opinions are on things like the randomsound daemon that is available for Linux. Similarly, any hardware with an ADC input can be used as a hardware random noise source, simply by cranking up the gain to suitable levels where the low-order bit is sampling thermal

Re: [Cryptography] In the face of cooperative end-points, PFS doesn't help

2013-09-08 Thread Marcus D. Leech
On 09/07/2013 06:57 PM, james hughes wrote: PFS may not be a panacea but does help. There's no question in my mind that PFS helps. I have, in the past, been very in much favor of turning on PFS support in various protocols, when it has been available. And I fully understand what the

Re: [Cryptography] In the face of cooperative end-points, PFS doesn't help

2013-09-06 Thread Marcus D. Leech
It seems to me that while PFS is an excellent back-stop against NSA having/deriving a website RSA key, it does *nothing* to prevent the kind of cooperative endpoint scenario that I've seen discussed in other forums, prompted by the latest revelations about what NSA has been up to. But if

Re: [Cryptography] Why prefer symmetric crypto over public key crypto?

2013-09-06 Thread Marcus D. Leech
The magic of public key crypto is that it gets rid of the key management problem -- if I'm going to communicate with you with symmetric crypto, how do I get the keys to you? The pain of it is that it replaces it with a new set of problems. Those problems include that the amazing power of

Re: [Cryptography] Using Raspberry Pis

2013-09-06 Thread Marcus D. Leech
On 09/07/2013 12:04 AM, Ben Laurie wrote: On 26 August 2013 22:43, Perry E. Metzger pe...@piermont.com mailto:pe...@piermont.com wrote: (I would prefer to see hybrid capability systems in such applications, like Capsicum, though I don't think any such have been ported to Linux