Announcing Blockstream Satellite
blockstream.com
blockstream.com
And, no, Blockstream didn't launch their satellites, they simply used an existing satellite service provider. I used to work for Smartjog who did the same. In fact I wrote the software (RBC, Reliable Bit Cast) used to send the actual satellite data packets through our provider Intelsat. The way it works is pretty simple. We had a server collocated in Intelsat's "teleport" in Riverside (http://www.intelsat.com/global-network/intelsatone/teleports...). I walked into their data center, racked our server, hooked it up (yeah I did IT too, we were a small company back then.) And they tell you to send a stream of UDP/IP packets to one of their TCP endpoints, which ingests data into their satellite infrastructure. On the receiver's end all you need is a standard dish hooked to a DVB card. Can't remember which one we used, but it had a Linux driver that presented a virtual network interface, and Linux received the IP traffic just as if it was a standard Ethernet NIC. I don't know the cost of this Intelsat service, but it can't be that high, maybe $5-20k/month for the lowest bandwidth option.
On another side note, more companies broadcasting the blockchain and covering more of the planet (the real time map shows Asia as not covered) will eventually put the "block propagation delay" argument in the tomb, for those arguing against big blocks.
Also latency on satellites is atrocious.
(Not my blog, I just had the same idea on reading the article)
Figuring out Bitcoin's best chain (PoW-wise longest) and remaining in consensus with the rest of the network is the hard part: it requires on-going communications on a reliable uncapped/high-capped internet connection, introduces trust, and adds the risk of fraud (someone feeding you with an alternative best chain that's not recognized by the rest of the network as such could execute double-spend attacks against you [0]).
[0] Blockstream satellite is no different in this regard: Blockstream could feed incorrect data into their satellites. But as a farmer in India, I would feel more comfortable trusting a satellite signal from an internationally known company that many other people are also getting (and audit, and hopefully sound an alarm if something goes wrong) then trusting, say, some internet-connected device two villages away.
I have never seen any interest from governments actually blocking blockchain data, or in general censoring bitcoin traffic. Using bitcoin via internet will highly probably stay the cheapest and easiest method in the future, unless really there is need to have millions/billions of nodes. Doesn't look to me like that, in fact I think quite many bitcoin nodes are just hobbyist nodes that don't actually do any payment processing except for few random personal transactions. So it is quite difficult to see the applications for this, unless made "just for fun".
These projects are just cool PR stunts. And they actually seem to work as such pretty well.
Edit: a second paper (2016) has similar findings: 10% of nodes haven't received the block after 79 seconds: http://fc16.ifca.ai/bitcoin/papers/CDE+16.pdf
I really loved Smartjog for a while and even commissioned a couple of devices in the UK. It was a real shame the likes of Aspera and Signiant won that space.
I seem to recall the RBC library was open source. Is that still available somewhere?
Um, no.
First of all the limiter needs to be the decentralized internet p2p relay, since even a federation of satellite broadcasting companies is unacceptable. This is adversarial engineering where you design to operate in the worst case.
Second, it is validation of a block that matters, not mere receipt of the header. So how long it takes to transmit a block over the low bandwidth connection such a satellite provides, plus the time to validate CAN be significant as you increase the blocksize beyond the current 4MB.
The p2p overlay network should remain the backbone of Bitcoin. It is perfectly adequate for most nodes, however critics of large blocks have used the argument that a small percentage of nodes just don't even have adequate internet bandwidth. Now a satellite service gives them the guarantee they can receive blocks, no matter their size (bandwidth is sized appropriately), very cheaply, no matter where they are located in the world, no matter how bad their internet connection is.
"Second, it is validation of a block that matters"
I never said this satellite service will magically fix everything, just that it removes ONE hurdle of many.
Anyone have any idea how much renting spectrum from a comm satellite costs?
Apparently this startup has $55M in funding but if I was an investor I'd be wondering what the hell they're doing right about now.
I wouldn't be surprised if they're trying to pivot to something else...
After all - what could go wrong?
https://blockstream.com/about/
> Blockstream's primary area of innovation is in sidechains, a technology invented to extend the capabilities of Bitcoin's blockchain. Sidechains create the opportunity for new models of trust, extending and improving upon the properties of Bitcoin.
Blockstream is quite a weird company in the bitcoin space. No one seems to have much idea what their business model could be. At the same time they are quite involved with bitcoin core development, which has caused people to make all kind of conspiracy theories etc about them. They probably put a lot from that VC investment to Bitcoin, so they probably have cash to do all kinds of funny things for quite a long time still.
No one seems to have much idea what their business model could be.
> In this instance, the first objective is to increase the public good by strengthening the overall openness and functionality of the Bitcoin ecosystem through “sidechains” technology. Delivering returns to investors is an objective as well – but it’s a secondary objective. ...
> And that’s why I’m participating in this first-round financing as an individual investor, and why Blockstream itself will function similarly to the Mozilla Corporation. Here, our first interest is maintaining and enhancing Bitcoin’s strong open ecosystem. And the structure we’ve chosen will give us the freedom and flexibility to prioritize public good over returns to investors.
> Over time, I believe this ecosystem-first approach will ultimately create massive economic value – for everyone in the Bitcoin universe, including individual users, businesses of all types, developers, entrepreneurs, and investors.
https://www.linkedin.com/pulse/20141117154558-1213-the-futur...
quite involved with bitcoin core development
And perhaps those investors happen to also have investments in Bitcoin or other companies that depend on the success of Bitcoin.
0) Biggest barrier is probably TX fees which range from cents to $5 per transaction. (see argument down thread for arguments over how much). 1) you still need a network connection to send payments. 2) Given that connection, you can query for proofs a TX was included in a block fairly cheaply.
Anyone interested in an actual payment system for developing world that works without networking should look at DigiTally [0]which has seen some real world usage, works with sim cards and feature phones, and does not require a network connection
The satellite does lower the bandwidth costs of operating a node, since block distribution is literally a broadcast network. Its cool. But beyond the marketing angle, I am lost as to why Blockstream chose to do this now.
[0] https://www.cl.cam.ac.uk/~kabhb2/papers/DigiTally_SOUPS2017.... …
You can imagine a hub per small town acting sort of as a "bank" which is listening to the blockchain.
You make payments with your local peers through some mesh-network, and once a week (or whenever the channels with the hub are open) they go to close the channels out at the hub.
I'm more worried about how these people will acquire their first Bitcoins.
The bandwidth costs of that approach are larger, but still minimal.
I suppose the one thing it does is make it easier for the hub to monitor for channel closure? But you could contract a third party service that messages you when that happens. Granted, that's a less verifiable trust assumption in a third party than they are broadcasting every block they get.
Today, they have much cheaper options, though every transaction looks to take several days.[0]
Amusingly, their Price Estimator [1] continuously reloads with adblockers enabled.
[0] http://onlinefx.westernunion.com/Fees
[1] https://www.westernunion.com/us/en/price-estimator/continue....
Both of those figures are pulled high by exceptionally valuable and exceptionally large transactions, respectively, of course. Medians might be a better statistic, for which the figures are around $700 (median transaction value) and $1.50 (median transaction fee).
To btc-e couple of hours before it went offline. :(
Another transaction with 0.00055 BTC fees did get picked up, after spending a couple hours in the mempool.
The "small block policy" view[1] is held by nearly every technical participant of the bitcoin space[2][3], myself included. Claiming that blockstream are somehow "forcing" anything is pure conspiracy nonsense.
[0] https://bravenewcoin.com/news/bitcoin-spam-attack-stressed-n...
[1] that is, the "let's start by doubling the blocksize with segwit first, analyze the results and then talk about further increasing it" view. not sure how valid the "small block" label is, considering that the people you're labeling with it want to double the block size.
Some wallets do still have broken or easily games fee estimations (Blockchain's is notorious. Armory broke down completely.) That is a problem that should have been fixed already but can only be adressed by their respective developers.
However, even at $.5 many use cases are priced out of the network. On chain gambling most notably. This problem is inherent to the extreme replication factor trustless global systems require and is definitively not something that is advocated one way or another.
I used to do a bunch of digital SDR on my boat but it used too much power so I gave up (was living on solar)
How does the company intend to make money off of these satellites?
> the value of a digital currency and payment system that is not controlled by governments, banks, or companies, but instead where each user directly owns their money.
In theory it sounds good, but the reality seems to be that most users just use an exchange to store their coins with KYC norms. And if bitcoin adoption increases among non-tech users, it's likely that they would just use a hosted wallet.
On a related note, can someone comment on my understanding of the block size debate : small blockers (Core devs + Blockstream) want to build the Lightning network, which is currently a white paper and promises low transaction fees + micropayments. The big blockers argue that this introduces centralization and accuse companies like Blockstream of wanting to turn monetize these Lightning hubs and potentially introduce KYC norms. The big blockers want to scale Bitcoin by increasing the blocksize, which is lucrative for the miners (a large portion of mining takes place in China). This solution will work for a while, but it's impossible to reach VISA level transaction rates with big blocks alone. Some points the big blockers make is that it's in line with Satoshi's vision and also maintains the p2p nature of Bitcoin where exchanges and KYC norms play a lesser role.
So this seems like a fight for the monetary spoils more than anything else : big blocks mean the miners mint money and small blocks mean side chain technologies become lucrative (which favours Blockstream and the core devs).
Whether bitcoin uses small blocks + segwit + side chains or uses big blocks (Bcash), it's hard to maintain the p2p + pseudonymous nature of transactions if it goes mainstream. KYC norms seem inevitable, whether at exchanges, hosted wallets, or to make a legal purchase using bitcoins.
So to me, what people really seem to want is an anonymous (crypto)currency that can be used to make purchases over the internet without any KYC norms. That used to be the primary use case for Bitcoin and probably still is. So, long term, what's the point of Bitcoin/Bcash if it's not truly p2p, where coins are held in hosted wallets and where KYC norms are necessary. I just don't see how Bitcoin can replace or even complement the traditional currencies. Would love to hear comments on this rant. (I am not on any side of the size debate, just a curious bystander)
Couple additions:
- there are a few lightning implementations already out there (see https://github.com/lightningnetwork/lnd), three I believe, and they have worked on being interoperable. Getting segwit activated was a big blocking (hah!) point towards being able to actually use those, and that happens soon so we may start seeing some more activity in that space very soon now.
- I don't think lightning necessarily means KYC, at least no more so than any other bitcoin->bitcoin transaction. It is basically all the same thing as current bitcoin transaction except things are kept off chain until someone wants to settle (or the channel approaches its timeout). This took me a long time and many videos to grok but it is pretty clever and has me excited about Bitcoin scaling to everyday use again. But ya, though the specter of regulation is always looming there isn't anything in lightning that necessarily makes that worse.
The whole big block / small block thing is absolutely nuts in the amount of trolling that takes place, so totally expect some crazy replies to this.. troll on brothers!
Lightning is working code, not a white paper:
It's cool, but really just a glorified form of APRS being broadcast over digipeaters, except the digipeaters being used are in orbit.
LW/HF is simpler and cheaper to run. Its way more simple to design a reciever for as well. Granted RTLSDR dongles will need an upconverter, but compared to installing and running a dish, its trivial.
With normal Bitcoin an attempt to do this would be massacred by the collective hashing power.
But if all you have is the satellite link and no internet, you can't get confirmation from other peers.
So if you imagine blockstream as an attacker, they could broadcast their version of the chain which say doesn't include payments they made on the main chain so that they could "double spend" them in places that rely solely on the satellite for truth.
Or am I missing something?
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edit: I guess there's no way for blockstream to create blocks at the appropriate difficulty level fast enough, so it would be pretty obvious if they were trying to create their own fork. So I guess this does work..
Edit: responding to your edit. Yes a good point!