You can now perform all basic actions in Bitcoin through SMS
blog.coinbase.com
You can now perform all basic actions in Bitcoin through SMS
1–10 of 28 posts
Re: You can now perform all basic actions in Bitcoin through SMS
#2Holy shit. This just changed the game. Venmo best be scared bc bitcoin is perfect for early p2p adoption. Much lower barrier than between consumers and businesses.
Re: You can now perform all basic actions in Bitcoin through SMS
#3I don't know what the impact of this will be in first-world countries, but it strikes me that this will really open bitcoin up in developing countries that have poor data availability. Just look at what M-PESA has been able to do via SMS.
Re: You can now perform all basic actions in Bitcoin through SMS
#4Wow, this is simultaneously really cool from a usability perspective, but terrifying from a security perspective. A non changing PIN sent over cleartext (encrypted by "speech"). I guess there is plenty of room for security on the backend.
It is more than fine for casual uses, but a serious user who publishes his phone number (payment address) would be subject to a really cheap attack by anyone who can look at his phone, or a somewhat cheap attack with the ability to reroute the phone, or a slightly cheap attack with local BTS spoofing.
Re: You can now perform all basic actions in Bitcoin through SMS
#5Wow, this is simultaneously really cool from a usability perspective, but terrifying from a security perspective. A non changing PIN sent over cleartext (encrypted by "speech"). I guess there is plenty of room for security on the backend. It is more than fine for casual uses, but a serious user who publishes his phone number (payment address) would be subject to a really cheap attack by anyone who can look at his pho…
I assume they're checking the incoming phone number as well. So the thief needs to get your SIM card or hack the phone system. Can anyone chime in as to how difficult the latter (and how prevalent the former) is?
Re: You can now perform all basic actions in Bitcoin through SMS
#6Wow, this is simultaneously really cool from a usability perspective, but terrifying from a security perspective. A non changing PIN sent over cleartext (encrypted by "speech"). I guess there is plenty of room for security on the backend. It is more than fine for casual uses, but a serious user who publishes his phone number (payment address) would be subject to a really cheap attack by anyone who can look at his pho…
I assume they're checking the incoming phone number as well. So the thief needs to get your SIM card or hack the phone system. Can anyone chime in as to how difficult the latter (and how prevalent the former) is?
Spoofing the SMS on the request is easy (only policy at operators prevents it).
You do need to intercept the incoming call, but you can trivially do that ith call forwarding, or more impressively do it with network or local handset exploits.
Re: You can now perform all basic actions in Bitcoin through SMS
#7Earlier quoted context omitted.
I assume they're checking the incoming phone number as well. So the thief needs to get your SIM card or hack the phone system. Can anyone chime in as to how difficult the latter (and how prevalent the former) is?
Spoofing the SMS on the request is easy (only policy at operators prevents it). You do need to intercept the incoming call, but you can trivially do that ith call forwarding, or more impressively do it with network or local handset exploits.
We've tried to make it as secure as possible. The idea is that the pin is only sent over the call. So the hacker would need to listen in to your call in order to steal your pin. So they basically need to hack your SMS and your voice calls. How else can we make this more secure?
As for publishing your phone number so that you can receive bitcoins, you can publish your secondary phone numbers. We only allow you to use SMS to access your account from your primary phone number, but you can receive funds on any other phone number attached to your account. So even if a hacker knows your pin and is able to fake a call to us from your published phone number, they won't have access to your bitcoins.
Re: You can now perform all basic actions in Bitcoin through SMS
#8Holy shit. This just changed the game. Venmo best be scared bc bitcoin is perfect for early p2p adoption. Much lower barrier than between consumers and businesses.
Yeah. Bitcoin's a great way to bump cash between people. That said, there's so much $ being poured into different mobile payment methods that I'd be hesitant to call it the clear front runner.
Also, you still haven't called me about the hackathon, David.
Re: You can now perform all basic actions in Bitcoin through SMS
#9Earlier quoted context omitted.
Spoofing the SMS on the request is easy (only policy at operators prevents it). You do need to intercept the incoming call, but you can trivially do that ith call forwarding, or more impressively do it with network or local handset exploits.
We've tried to make it as secure as possible. The idea is that the pin is only sent over the call. So the hacker would need to listen in to your call in order to steal your pin. So they basically need to hack your SMS and your voice calls. How else can we make this more secure? As for publishing your phone number so that you can receive bitcoins, you can publish your secondary phone numbers. We only allow you to use…
Yeah, it is probably about as secure as is reasonably needed. You should also have daily and maybe total limits, do statistical anti fraud (useful in general, but more so on low trust channels)
You might be more willing to allow large repeat transactions vs large transactions to a new payee.
I haven't tried it yet, but you definitely want the voice call to include both as much transaction info as possible and a "press 0 to talk to security" etc.
Unclear which telephony provider you use, but if you are more partnered with carriers, you can see more data, which may help reduce fraud. If you turn out to have a bunch of users in Nigeria, I'd set up peering directly with the Nigerian mobile carriers. This is probably years down the line.
I'd personally be willing to risk 10-20 BTC to this level of security, but not 500. Of course, my Bitcoin holdings are 2-3 BTC right now.
The big risk is the link between Coinbase and your outsourced telephony provider. Worst case, if someone is defrauded out of 5 BTC, he can eat it, or you can eat it -- it's not material to you. However, if I can somehow compromise the entire thing and take 10% out of every enabled-for-sms account, that might be material to Coinbase. I'd make sure the entire path is secure, and do as much verification in-house as possible, and probably put aggregate limits on the whole thing.
To be clear, I like the idea here, and think it is a great thing to deploy, it just makes me scared because it is a huge step down from the rest of coinbase's security. Since it is opt-in maybe it doesn't matter as much.
Re: You can now perform all basic actions in Bitcoin through SMS
#10I'm hoping they open source the SMS handler library used for this.