Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Maybe Blockchain Really Does Have Magical Powers

bloomberg.com

Post reply on HN
Print view View original

31–40 of 104 posts

Re: Maybe Blockchain Really Does Have Magical Powers

#31

Post by Marazan »

jcoffland wrote: post #15

> The technological innovation of a blockchain is that it combines cryptographic signatures with a fault-tolerant distributed database. This is the naive view that has allowed the financial industry to ditch Bitcoin and run with blockchain. The problem that Bitcoin solves and private blockchains do not is called the Byzantine generals problem which did not have a known solution until Bitcoin came along. Private block…

What? The Byzantine generals problems most certainly did have solutions before Block chain came along.

Re: Maybe Blockchain Really Does Have Magical Powers

#32

Post by the_mitsuhiko »

lhl wrote: post #3

I'm all for deflating blockchain hype, but I found the overall tone of the article pretty disagreeable, and more importantly, wholly missing the point. "In other words, the only thing previously stopping the standardization of reconciliation processes was the unwillingness of financial institutions to collaborate." No, actually, the one thing the blockchain provides, which was literally unsolved before pre-Nakamoto,…

> No, actually, the one thing the blockchain provides, which was literally unsolved before pre-Nakamoto, was a working implementation of "trustless" consensus.

That's the part banks do not care about so I think it's largely irrelevant in the context of this article.

Re: Maybe Blockchain Really Does Have Magical Powers

#33

Post by ojosilva »

lhl wrote: post #3

I'm all for deflating blockchain hype, but I found the overall tone of the article pretty disagreeable, and more importantly, wholly missing the point. "In other words, the only thing previously stopping the standardization of reconciliation processes was the unwillingness of financial institutions to collaborate." No, actually, the one thing the blockchain provides, which was literally unsolved before pre-Nakamoto,…

And things like Smart Contracts are relatively new (1994), even though the concepts had been laid out in the 1970s. Smart Contracts are part of what makes blockchain more versatile, enabling transaction ledgers that can support the level of overwhelming (and sometimes unnecessary) complexity BFSIs can produce.

Unfortunately, even at this point, Smart Contracts probably still have many security challenges to overcome before banks can adopt it.

Re: Maybe Blockchain Really Does Have Magical Powers

#34

Post by DSMan195276 »

valkea wrote: post #25
pipermerriam wrote: post #18

Earlier quoted context omitted.

Any blockchain client for any chain (Bitcoin, Ethereum, Dogecoin, ...) could very easily implement a storage layer for the underlying blockchain data using a protocol like IPFS. https://ipfs.io/ In this model, individuals would not need to store the entire chain as they could lazily fetch parts of the chain as they are needed. This would allow individuals to store very little of the historical blockchain data if thei…

How would you ensure the validity of the part of the blockchain you are reading from IPFS?

You may be aware, since you're asking the question, but you really can't without some other information.

If you have block D, and want to fetch block A, you don't actually know if it's the real block A unless you also have blocks B, and C. Block D (which you have) contains the hash of block C, which contains the hash of block B, which contains the hash of block A. You need the hash of block A to be able to verify that it is indeed the real block A.

Of course, because of things like SSL/TLS, you can be sure nobody tampered with the block on it's way from the server to you. With that in mind, ensuring you receive the real block just requires you to trust the server giving you the blocks, which may or may not be worth it depending on how much time/space it saves you. In some ways, the server would become your 'central authority' on the block-chain.

In reality though, I can't really imagine there's much they could do. Sending you fake blocks may work for a while but would fail if the client caches them and asks for the surrounding blocks (Their fake block isn't going to match the hash of the real block). I think it would be a bit hard to pull off for any length of time.

Re: Maybe Blockchain Really Does Have Magical Powers

#35

Post by lhl »

kfk wrote: post #6

Can somebody explain me how we deal with the increasing size of a blockchain? I get moore's law etc., but other than that? I mean, it's trillions of transactions we are talking about. Federated servers? We break the chain in some way?

The Bitcoin whitepaper [1] (which is very short, concise, and definitely worth the read) describes how the Merkle trees might be pruned (transactions could be pruned when all outputs are spent) and in fact Bitcoin 0.11 added pruning (and 0.12 added further compatibility for pruned nodes).

Vitalik Buterin (Ethereum lead) also posted a description of how Ethereum will implement State Tree Pruning [2].

These are short/medium-term scaling solutions.

Many people are pushing sidechain [3] / child-chains [4] as longer-term ("Visa" level) solutions.

* Lightning Network [5][6] is what Blockstream and others are pushing for Bitcoin scaling.

* Raiden Network [7] is the Ethereum version, and may come out before Lightning, funnily enough.

For those interested in the topic matter, Vitalik wrote a pretty dense paper on blockchain scaling last year [8].

While sidechains will be an option, Ethereum is also pursuing on-chain scaling as well.

Sharding is scheduled for the upcoming Serenity release [9] (which also switches to Proof of Stake (Casper), another important scaling-related change). Writeup on Serenity PoC2 [10].

In general for scaling atm, processing/network latency/bandwidth for initial sync is more of a bottleneck than raw storage. By that measure, I'm actually a lot more interested in the on-chain tx-processing that Casper/PoS might bring [11].

Of course there's no requirement for a single chain to handle everything. Especially over the past few months, we've seen a few relatively smooth migrations to multiple chains as Bitcoin tx processing has "maxed out" (or more recently as fungibility/privacy issues have loomed). At the same time, Bitcoin volatility has stabilized, so it might be just the natural life cycle for blockchains to "scale" until they can't. It's still early days, so who knows?

[1] https://bitcoin.org/en/bitcoin-paper

[2] https://blog.ethereum.org/2015/06/26/state-tree-pruning/

[3] https://gendal.me/2014/10/26/a-simple-explanation-of-bitcoin...

[4] https://www.ardorplatform.org/

[5] https://lightning.network/

[6] https://lightning.network/lightning-network-paper.pdf

[7] http://raiden.network

[8] https://github.com/vbuterin/scalability_paper/blob/master/sc...

[9] https://github.com/ethereum/EIPs/issues/53

[10] https://blog.ethereum.org/2016/03/05/serenity-poc2/) from March

[11] https://twitter.com/VitalikButerin/status/760185856057638913

(phew, maybe one day HN will have markdown support, maybe one day...)

Re: Maybe Blockchain Really Does Have Magical Powers

#36

Post by twblalock »

spullara wrote: post #23
Kinnard wrote: post #13

Earlier quoted context omitted.

Why can't you place multiple bets? Hedging?

Goes back to an old stock prediction scam. You choose 1024 and send 512 the prediction that a stock will go up and 512 the prediction that the same stock will go down. Each day you repeat this process only with the group where you were right. So, 512 -> 256 -> 128 -> 64 -> 32. Eventually you have a small number of people that think you can predict the future and you can ask them for money that you will invest on thei…

This also happens in the sports betting world. People use this method to convince others that they can consistently predict the outcome of games, or the spread, or the other stuff people want to bet on.

Re: Maybe Blockchain Really Does Have Magical Powers

#37

Post by wmf »

jcoffland wrote: post #21
skybrian wrote: post #19

Earlier quoted context omitted.

True, but not necessarily that important. In world of Bitcoin this is important due to anonymity and criminal activity. In a regulated industry there are other ways to prevent cheating. Making cheating obvious and undeniable is probably enough to prevent it from happening (due to legal risk).

If a private blockchain forks how do you decide which one was the cheaters branch and which one legit?

The legit branch is signed/vouched by at least (N/2)+1 parties and the cheating branch has less than (N/2)-1.

Re: Maybe Blockchain Really Does Have Magical Powers

#38

Post by lhl »

the_mitsuhiko wrote: post #32
lhl wrote: post #3

I'm all for deflating blockchain hype, but I found the overall tone of the article pretty disagreeable, and more importantly, wholly missing the point. "In other words, the only thing previously stopping the standardization of reconciliation processes was the unwillingness of financial institutions to collaborate." No, actually, the one thing the blockchain provides, which was literally unsolved before pre-Nakamoto,…

> No, actually, the one thing the blockchain provides, which was literally unsolved before pre-Nakamoto, was a working implementation of "trustless" consensus. That's the part banks do not care about so I think it's largely irrelevant in the context of this article.

I spoke at length w/ a friend working on mortgage-backed securities for GS a few years ago and dealing with third-party (and even intra-office) trust was specifically why he was looking into blockchains, but I'll admit to not being super familiar w/ R3's blockchain implementation. If anyone has a less diatribey and more technical resource they could link to that'd be great.

Re: Maybe Blockchain Really Does Have Magical Powers

#39

Post by tromp »

DSMan195276 wrote: post #34
valkea wrote: post #25

Earlier quoted context omitted.

How would you ensure the validity of the part of the blockchain you are reading from IPFS?

You may be aware, since you're asking the question, but you really can't without some other information. If you have block D, and want to fetch block A, you don't actually know if it's the real block A unless you also have blocks B, and C. Block D (which you have) contains the hash of block C, which contains the hash of block B, which contains the hash of block A. You need the hash of block A to be able to verify tha…

> unless you also have blocks B, and C.

It suffices to have the headers of blocks B and C. Which, at only 80 bytes per header, is quite manageable.

Re: Maybe Blockchain Really Does Have Magical Powers

#40

Post by lhl »

mtkd wrote: post #28
gbarc888 wrote: post #22

Earlier quoted context omitted.

The banks aren't using trustless consensus. They're using a third-party "uniqueness service" to prevent fraud.

I doubt this message will propagate further than technical forums - you're just going to have suck up the homogenization, pasteurization, retail branding and consumer promotion of a once great technology

Interesting, my original understanding was that they were using the blockchain for uniqueness for Corda, but it looks like it's optional: https://r3cev.com/blog/2016/4/4/introducing-r3-corda-a-distr...

This somewhat makes sense since one of Corda's departures is that consensus and validation are limited in scope to the participants.

Post reply on HN