voldz1tic3n 2017-01-16 07:56:47
how can I buy bitcoins with USD?
Chris_Stewart_5 2017-01-16 07:59:00
Bloomberg on algorithmic traders trading bitcoin: https://www.bloomberg.com/news/articles/2017-01-16/high-speed-traders-are-taking-over-bitcoin-as-easy-money-beckons
piqure 2017-01-16 07:59:02
^^^ WARNING: any URL may lead directly or indirectly to COIN-STEALING MALWARE! ^^^
cluelessperson 2017-01-16 08:09:44
voldz1tic3n, So, this is the currently biggest problem in bitcoin (I think), adoption.
cluelessperson 2017-01-16 08:10:02
voldz1tic3n, But, you can buy from, ATMs, traders, exchanges
cluelessperson 2017-01-16 08:10:07
voldz1tic3n, I like localbitcoins.com :)
cluelessperson 2017-01-16 08:10:37
Hi all, I'm thinking about making my own physical bitcoins, really high quality ones
cluelessperson 2017-01-16 08:10:40
hopefully reusable
cluelessperson 2017-01-16 08:10:57
how do you suggest I make the private key tamper evident?
Shadouts 2017-01-16 08:12:04
it's not good to reuse a private key.
iz 2017-01-16 08:12:12
the problem w/ a design like that.. is you can't tell if you are getting scammed by paying money for physical bitcoins, unless you destroy them
cluelessperson 2017-01-16 08:12:48
iz, you can confirm the address has funds, right?
iz 2017-01-16 08:12:52
there's no way to test if the private key is legit, without disclosing it
cluelessperson 2017-01-16 08:13:04
iz, understood.
iz 2017-01-16 08:13:13
how do you know the private key that is suppose to be inside the physical token is really associated to the account they say it is?
iz 2017-01-16 08:13:51
it could just be random and you would never know until you destroy the physical token to try to use the private key
abpa 2017-01-16 08:14:25
cluelessperson you could use a hardware chip to generate the private key
cluelessperson 2017-01-16 08:14:36
abpa, what do you mean?
Shadouts 2017-01-16 08:15:02
cluelessperson: OpenDime solved this problem.
abpa 2017-01-16 08:15:06
Embed a chip and the chip itself generates the private key and never has anything to reveal it
iz 2017-01-16 08:15:46
there are still many problems w/ those designs
cluelessperson 2017-01-16 08:15:50
Shadouts, abpa I saw that. So now I'm thinking I want to embed their hardware in my coin. :)
cluelessperson 2017-01-16 08:15:56
and epoxy the shit out of it
poutine 2017-01-16 08:15:57
Those devices likely have physical access attack vectors
iz 2017-01-16 08:16:06
because you can't be certain that whoever sold you the physical tokens doesn't also have a copy of the private key (assuming it is legit)
iz 2017-01-16 08:16:22
also, embedded hardware is super easy to extract crypto from
cluelessperson 2017-01-16 08:16:35
iz, ... not if it has tamper detection
cluelessperson 2017-01-16 08:16:48
I've done some research on that topic. :)
iz 2017-01-16 08:16:52
it can be done pretty easy with power analysis
iz 2017-01-16 08:16:59
google about SPA and DPA
iz 2017-01-16 08:17:17
you can actually extract the private key from a phone doing NFC transactions just using an antenna from a distance
abpa 2017-01-16 08:17:31
I don't think you can get private data out of secure hardware
poutine 2017-01-16 08:17:44
abpa, who deems this hardware secure?
iz 2017-01-16 08:18:04
there is a surprising amount of "secure" embedded hardware that DPA/SPA attacks work brilliantly on
abpa 2017-01-16 08:18:13
Who says that any computer is doing what it says it is?
cluelessperson 2017-01-16 08:18:31
abpa, I've seen some awesome secure hardware
iz 2017-01-16 08:18:42
and the company that really does those types of attacks of course has patents on hardware the defends against it
cluelessperson 2017-01-16 08:18:58
abpa, I came across this HSM, they encase it in tamper sensing wires, and epoxy the SHIT out of it
iz 2017-01-16 08:19:10
so if you want to make embedded hardware resistant to those types of attacks.. you have to do some licencing w/ them or risk legal action
abpa 2017-01-16 08:19:11
There's definitely a range of solutions, but Apple and Intel's solutions for example seem like they are pretty hardened, like to the electron microscope to extract data level
poutine 2017-01-16 08:19:26
cluelessperson, Do you really think epoxy means much to someone determined?
abpa 2017-01-16 08:19:31
If they use epoxy I'd be worried rather than reassured
iz 2017-01-16 08:19:39
yeah, with SPA/DPA you don't have to remove epoxy or meshes or anything
iz 2017-01-16 08:19:53
it's just power analysis of the hardware doing the crypto math
cluelessperson 2017-01-16 08:19:56
poutine, yes, especially when you embed temperature sensing, acid detection, and tamper wires in the epoxy if someone tries to drill
iz 2017-01-16 08:20:16
you have to catch the device doing crypto operations with the private key
iz 2017-01-16 08:20:29
and with DPA, you need to make it do _many_ crypto operations with the private key
abpa 2017-01-16 08:20:37
You could embed 2 chips from 2 totally separate companies
poutine 2017-01-16 08:20:58
The device also has to store a private key, there are some methods of obscuring, and making that more secure, but it must access it somehow, and you don't likely need the full circuit to do that
poutine 2017-01-16 08:21:03
including any tamper stuff you have on it
iz 2017-01-16 08:21:05
but if the implementation is vuln, then you can get it by just examining the EMR that comes off it
abpa 2017-01-16 08:22:16
Keep it powered off?
iz 2017-01-16 08:22:26
if you can use it to verify the private key is legit, then you could do SPA/DPA attacks, i think
iz 2017-01-16 08:22:29
at least SPA
iz 2017-01-16 08:22:39
there might be a way to verify the private key that is safe from DPA
iz 2017-01-16 08:23:51
bitcoin really isn't meant to have a physical token.. everything about it just weakens the security or increases the scamminess
moli_ 2017-01-16 08:35:19
j #bitcoin-core-dev
cluelessperson 2017-01-16 08:36:50
iz, EMR, use something that obscures it or adds noise?
cluelessperson 2017-01-16 08:37:04
iz, lol, kinda agree
cluelessperson 2017-01-16 08:37:14
I mean this more as an award for certain people.
iz 2017-01-16 08:37:43
cluelessperson: yeah, there are several techniques that can be used to obscure it, but rambus/CRI owns all the patents on them and sells special embedded hardware that is resistant to these types of attacks
iz 2017-01-16 08:37:54
but, of course, it's expensive
iz 2017-01-16 08:38:59
and even IF the private key is secure and can be verified, but not extracted from the token..
cluelessperson 2017-01-16 08:39:00
iz, they own the technique?
cluelessperson 2017-01-16 08:39:09
iz, even if I figure it out on my own without copying theirs?
iz 2017-01-16 08:39:29
they own the defense techniques, yeah.. they will send a fleet of lawyers at you
cluelessperson 2017-01-16 08:40:01
iz, My thinking is that I make a machine that creates the coin, address and private key, so that I *the manufacturer* don't even know the private key
iz 2017-01-16 08:40:01
anyway.. even if the private key is secure and can be verified.. you still have to trust that whoever sold you the token didn't keep a copy of the private key
cluelessperson 2017-01-16 08:40:06
no one verifies the private key
iz 2017-01-16 08:40:08
and that's something you can never verify
iz 2017-01-16 08:40:42
well, if the token creates the private key and everything, then it would be worth 0 btc
cluelessperson 2017-01-16 08:41:02
iz, the machine would add the private key, and the address
cluelessperson 2017-01-16 08:41:10
iz, it comes down to trusting me in this case.
iz 2017-01-16 08:41:33
and if it's preloaded with any btc in it, then you can't be sure the hardware really generated the private key and can't be sure whoever loaded it with BTC didn't keep a copy of the private key
norotartagen 2017-01-16 08:42:02
i don't see how you could make physical bitcoins that can be redeemed for virtual currency, without running a private company to do it
iz 2017-01-16 08:42:03
yeah, well if it comes down to just trusting you.. then you don't need to do anything with embedded microcontrollers..
iz 2017-01-16 08:42:14
and just put in on a microSD card or something cheap
cluelessperson 2017-01-16 08:44:21
iz, Yeah, it comes down to trusting that I didn't track the private key
