Kryptoradio – A Bitcoin data transmission system

http://kryptoradio.koodilehto.fi/

by mappum • 12 years ago

204 59 12 years ago

kryptoradio.koodilehto.fi

bagosm• 12 years ago

Thats all good and gimmicky but can you tell me: the 1-way connection offers any value to anyone?

danwills• 12 years ago

Could it be used for things like vending machines perhaps? You would still need a cellphone to pay but the machine would only need an antenna and cheapish chip to make it work.

ispshadow• 12 years ago

That's an incredible idea.

aw3c2• 12 years ago

And I just need a tiny DVB-T transmitter to feed my own blockchain to it. I like that idea of yours! :P

Retric4• 12 years ago

Sure, if your willing to wait 20+ minutes to get your drink.

servowire4• 12 years ago

With a DVB/Radio link to the network one could listen to transactions only to their address. You could think of bitcoin operated gas stations, bitcoin network-hubs in rural areas, micropayments to car-charging stations (all you need is power and a cheap DVB receiver to listen to the address "beacon" for a payment.

Now sending back transactions to the network is not covered, but can be done by using SMS or a small radio link to a local node. A bitcoin transaction is only about 64 bytes (!) so even a DTMF call or SMS should work fine.

A transaction send would look like this (normal TXid, in hex)

  a9d4599e15b53f3eb531608ddb31f48c695c3d0b3538a6bda871e8b34f2f430c

That would be

  76816061505687581068522220805344294890167166251289478281934616246172205973504

in DTMF. Would take about 15 seconds to complete (http://www.audiocheck.net/audiocheck_dtmf.php)

asdfaoeu• 12 years ago

Why not just send the confirmation back by SMS?

wyager3• 12 years ago

Would take about 15 seconds to complete

That's unfortunately not sufficient at modern transaction rates. Is there any reason you chose DTMF in particular?

Buge• 12 years ago

    a9d4599e15b53f3eb531608ddb31f48c695c3d0b3538a6bda871e8b34f2f430c

is just a transaction ID, not a transaction. A full transaction is longer. For example [1], a typical transaction with 1 input and 2 outputs, is 226 bytes.

[1] https://blockchain.info/tx/2e395e9567bd43d3eecd7a6bdf990387d...

VMG• 12 years ago

Yes, for the same reason a radio broadcast does.

Distribute valuable information (mined blocks and verified transactions) with a nearly constant cost in relation to the recipients.

FatalLogic• 12 years ago

It's a huge amount of 'free' bandwidth, and a one-way WAN connection can still be useful.

It is only at the stage of a gimmick, or a proof of concept, but if the broadcast service could be relied upon long term, then it might greatly reduce the bandwidth and connectivity costs for simple Bitcoin-enabled devices.

It's misleading to think of it as only a one-way connection, because a user naturally creates a two-way channel.

Imagine a situation where a user sends a payment to the blockchain, via mobile internet, which is then picked up by the device. That is a de facto two-way connection. The user's phone (or whatever) would communicate with the device by a local area connection, such as Wifi, QR code, Bluetooth, even a typed code etc.

Obviously, devices could also have a low bandwidth uplink connection, such as 3g, but it's interesting to think about how it might still be useful with only a 1-way connection. It depends somewhat on the rate and structure of the blockchain data transmission.

jtanner• 12 years ago

Fascinating idea. In the areas that this would work, would it not be simpler to just use a normal cell phones data connection or SMS?

pronoiac• 12 years ago

Say the blockchain's growing by a gigabyte a month.[1] I don't think SMS can support that much, especially times so many devices. Using a tv signal is more robust - you can support millions of devices, and transient 3G network failures will have less or no effect.

[1] I estimated. http://blockchain.info/charts/blocks-size

nawitus• 12 years ago

But the parking meter (etc.) doesn't need to handle the blockchain at all. It could use the SMS to communicate with a shared parking meter bitcoin transaction server. That said, broadcasting the blockchain is useful.

kylebrown2• 12 years ago

The idea is that a lot of devices wouldn't need a two-way connection, rather they could confirm payment with only a downlink.

johnyzee• 12 years ago

This means parking meters, vending machines, laundromats, etc. can receive bitcoin payments without an internet connection. That is actually really cool.

sspiff• 12 years ago

Well, only if the transmission is signed & trusted. Otherwise, an attacker could just spoof a payment by transmitting a modified blockchain close to the payment terminal.

Also, things like DVB tuners are not exactly cheap enough to be integrated into many devices (though FM receivers, which may be used in the future, are).

mappum2• 12 years ago

Not necessarily. If the installer of the machine checks that it downloaded the "real" blockchain, it would be expensive to forge new blocks to send to it.

makomk2• 12 years ago

DVB-T tuners are pretty cheap because they're highly integrated and mass produced in huge numbers - you can get USB receiver dongles for under $10 in single quantities. There are even SoCs that integrate a processor and DVB-T demodulator on a single chip, usually used for stuff like set-top boxes.

wyager3• 12 years ago

Otherwise, an attacker could just spoof a payment by transmitting a modified blockchain close to the payment terminal.

If the payment terminal used an SPV-like technology, the attacker would have to have a tremendous amount of computing power. This attack is not feasible, especially considering the relatively small reward of fooling an ATM or a parking meter.

gojomo• 12 years ago

The point of proof-of-work is that the attack you describe, "transmitting a modified blockchain", is very, very expensive. Essentially any plausible block is "signed & trusted" by the very-difficult partial-hash-collision embedded within.

throwaway7722• 12 years ago

Well, only if the transmission is signed & trusted. Otherwise, an attacker could just spoof a payment by transmitting a modified blockchain close to the payment terminal.

As noted in the article (under the "technology" page), signing is planned but not yet implemented.

Also, things like DVB tuners are not exactly cheap enough to be integrated into many devices (though FM receivers, which may be used in the future, are).

What kind of devices are you thinking of? It seems to me that the most useful applications of this system would be for vending machines. A $10 DVB-T demodulator (at scale they can be had much cheaper than that) is a rounding error in the cost of those devices.

tabrischen• 12 years ago

Indeed, this frees us from dependence on highly priced internet in developed countries and has so much potential in emerging markets.

kolev3• 12 years ago

The blockchain is big and ever-growing. If people really start transacting, like hundreds of millions a day pay their parking with Bitcoin, imagine the size of the data. Plus, Bitcoin can't handle it now with the 7 TPS limit.

ghshephard2• 12 years ago

Discussions on Scalability have suggested an eventual goal of 4,000 TPS are entirely reasonable.

https://en.bitcoin.it/wiki/Scalability

pistle• 12 years ago

If you are somewhere that network connectivity is an issue, there are usually free parking spots and no laundromats. I guess oasis vending machines could feasibly be an issue, but you're now hoping that some niche market solves some of bitcoin's problems around being a better solution than existing options.

Cryptocurrency's design targeted the libertarian dystopia related to the interdependent nature (and potential abuse) of governments and their currencies. Given that the dystopian context doesn't exist strongly enough, other options will continue to have advantages within the current context.

You're more likely to show benefits with this when you can provide oppressed peoples' crypto-wallets with balances that can be converted into subversive tools. This, of course, will gain more of certain types of attention than a young currency could want.

Paying for parking is easy as it is. Same with paying to wash clothes. If you can't get cities and coin-op owners to upgrade to card swipe technology, good luck with selling them on immature digi-currencies.

Cryptocurrency needs to think less about catching up in various verticals and more on creating the killer value app... and the problem is nobody is seeing big $'s around the things that today's currency transfer technology has trouble with. We're on the cusp of IoT. Internetless internet-based currency?

acd• 12 years ago

Talking about that, Can anyone please transmit wikipedia via long wave radio? It would be interesting in censor states. Hiding wikipedia in tv/movie firmware would also be a possibility.

oleganza• 12 years ago

How wikipedia is different from any other website useful for victims of police state?

Mangalor• 12 years ago

It's an encyclopedia of everything.

zouppen4• 12 years ago

We can do it. It's just data. Of course long waves carry very scarce amounts of traffic. DVB-T or even better approach would be using satellite. There are digital satellite technologies like DVB-S which could carry that kind of data. It's only a financial issue.

mike_hearn3• 12 years ago

It just moves the thing that gets censored from the website itself to the equipment needed to receive it.

Tycho• 12 years ago

Which is infinitely harder for authorities to control.

delbel• 12 years ago

I had a similar idea like this, but using shortwave instead of DVB.

sgy• 12 years ago

Are we going to witness another Clinkle sotry (http://www.businessinsider.com/inside-story-of-clinkle-2014-...)?

Kryptoradio – A Bitcoin data transmission system

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