13

Blockchains are data structures, whose only advantage is that storing data in that structure allows you to achieve decentralization under certain conditions. So your question reduces to "how is decentralization important"? Decentralized systems tend to have the following favorable attributes: Open (anyone can participate; not permissioned) Borderless (as ...


10

It depends on what you mean by "private". The word private is not really associated with Eris as far as I can tell. Rather, the word "permissioned" is used instead, and therein lies all the difference and your answer. A "private" blockchain might imply a blockchain that is not shared with anyone. Such blockchains would effectively amount to slow databases ...


9

Signed commitments with immutable history are all that’s required for proof of integrity. Moreover, assuming commitments are immutable (transactions can only be reversed by adding a new commitment that reverses the actions of the previous commitment), you only need to keep track of the most recent commitment. If the commitment signer is a known entity, a ...


8

Speaking as someone who has worked on a blockchain project for a bank, I can tell you that banks are interested for several reasons. Banks know they are ripe for disruption Due to a combination of heavy regulation and incumbency (mixed with a variable level of collusion), banks have remained relatively protected from the technological disruption that has ...


8

This is hard to answer, as "blockchain" isn't a very well defined thing. Often the term refers to some use of cryptography in a distributed system, but what it means beyond that depends on who you ask. To those who use it as a generic term, it is usually little more than a marketing term. If you assume that at least there is an actual chain of blocks being ...


6

Private blockchains can be seen as a new method for ensuring consistency in a distributed database, even if that database is an environment of perfect trust. There is an equivalence between how a blockchain prevents two transactions spending the same prior transaction output, and how multiversion concurrency control (MVCC) in a relational database prevents ...


5

@Davide's answer is correct but I expand the explanation a bit particularly regarding the blockchain. I´m beginner and I understood there is an unique huge common block chain to be used by world wide A crypto-currency like bitcoin requires people to run the bitcoin software that makes the whole system work; it is a Peer-to-Peer (P2P) network and each ...


5

It would make no sense for Visa to copy Bitcoin. Visa is a company built around control of a payment network. Visa's system only works because they control access and payment verification, which is what makes them money. In Bitcoin, no single entity is in sole control. There is no way to make money off of the transactions on the network except to put in the ...


4

How can I get a private key for this address There is essentially no way. Is it possible for me to withdraw my bitcoin I invested here? I don't have the private key No. It looks like you fell for a common scam. I've been asked to share wallet credentials to participate in mining. Is that a scam? my money gone from wallet scam BTC Stolen from ...


4

If your nodes are trusted, though, a blockchain isn't necessary at all, you know the code isn't malicious. So what is the point of a permissioned blockchain? Knowing someone's identity is not necessarily equivalent to trusting them, and not all trust is equivalent. Consider the typical example of a permissioned blockchain. Two (or more) banks want to batch ...


4

Researcher Arvind Narayanan stated his opinion on this matter in his post “Private blockchain” is just a confusing name for a shared database: It is true that adding signatures and hash pointers makes a shared database a bit more secure. However, it’s qualitatively different from the level of security, irreversibility, and censorship-resistance you get ...


3

Blockchain is a mere chain of blocks and this respect is worse than every database on earth. What makes the public blockchain unique is the proof-of-work that ensures that thousands of copies of the blockchain are probabilistically identical all across the globe and with no discrete authority trusted to manage them. A private blockchain is a ledger managed ...


3

There are thousands of identical copies of the Bitcoin blockchain which is kept in sync worldwide thanks to its protocols. You can consider that like a single-instance super-redundant data structure. It store all the Bitcoin transactions. Then, based on the same idea, many project launched similar blockchains (sync-ed in a much smaller number of nodes though)...


3

The Bitcoin blockchain is maintained and secured by people throughout the world: miners. They take care of the security and validation of the decentralized consensus rules. The incentive for those people is the bitcoin reward. Your own blockchain will need such people to secure your blockchain. How are you going to incentivize them to mine for your ...


3

There are a few ways to do it, I personally went into src/net.cpp and commented out the if condition that triggers the lookup starting at line 1266. // if (addrman.size() == 0 && (GetTime() - nStart > 60)) { // static bool done = false; // if (!done) { // LogPrintf("Adding fixed seed nodes as DNS doesn't seem to be available.\n"); ...


3

What is the reason? And Is it logical to use "Proof-of-Authority" for a "public" blockchain, in sense of keeping decentralization? Proof of Authority is, by definition, centralised. If the authority nodes go rogue, or fail to reach consensus, the network is useless. You could use it in public networks (some of the ethereum testnets are PoA), but it would ...


3

The testnet data directory is not ~/.bitcoin but rather ~/.bitcoin/testnet3. ~/.bitcoin holds the data for the main Bitcoin blockchain.


3

First lets distinguish between a blockchain and Blockchain as a Service (BaaS), because they're two different things. Bitcoin, and other crypto-currencies, use a distributed ledger in a peer-to-peer network - a blockchain. This is the original use of a blockchain. As you state correctly, the fundamental concept is that it is decentralized, permissionless ...


3

They're an obvious scam. I mean, absurdly obvious. I'm really baffled how anyone could fall for something like this. If someone had a way to reliably invest $10,000 and turn it into $120,000 in a month, what would they want your money for? At that rate, $10,000 would become over $800 quadrillion dollars in just a year, 2,400 times the amount of money that ...


2

I think you're mistaking PoW for a mechanism that guarantees the chain's correctness, rather than just a means for finding consensus. A blockchain (without PoW) is just an ordered list of batched updates to a database. PoW is one mechanism to guarantee that everyone eventually ends up on the same chain, but it doesn't guarantee that this chain is valid. ...


2

The line between a blockchain and a distributed database (or ledger) is currently blurred (some would say deliberately so given the hype surrounding "blockchains" at the moment). R3 have recently concluded that it does not make sense to use a blockchain for their enterprise use case as financial institutions do not want to publish data on all their ...


2

Frankly, I don't think your definitions are useful. But by your definitions, PoS makes a network permissioned by definition. In a proof-of-stake network, you can only participate in the validation of transactions if you possess the token, which you can only get from someone else who has the token and chooses to give it you. By your definitions, that makes ...


1

The private key you have is encrypted so to decrypt it you need to have a valid password that's why it is asking for the password. It can't be hacked, you need a correct password


1

Please note, you should never pay for a Blockchain Wallet private key. To receive a bitcoin, you only need to provide the sender with a bitcoin address from your wallet. I'm sorry to hear about the experience you've had. Very unfortunately, scammers as of late have been taking advantage of users new to the cryptocurrency space and their potential lack of ...


1

The question slightly exceeds capabilities of this q&a forum. Maybe better to search bitcointalk.org, there these type of requests get often discussed. Join one of the discussions there! Anyhow, we need developers, and people with fresh minds. Here my short shot at bitcoin, because we are in bitcoin q&a forum. You would probably want to create an ...


1

Nothing can prevent B from exposing or forwarding the data once he has access to it.


1

For question 1 and 2, ZCash (not Zikas) provides some solutions. It's based on Bitcoin's code and has 2 types of addresses: non-shielded: they behave exactly like normal Bitcoin addresses shielded: you can't know how much they are transacting nor to whom they're sending funds (unless it's to non shielded addresses). If you only use shielded addresses, and ...


1

Sure. You just use a database that keeps track of who has how much money. You can do this any way you want. You don't need anything fancy like POW, POS, or even a blockchain. The only reason you would need or want these things is to permit decentralized operation without a central authority. If you are the central authority, what you say is law just because ...


1

With blockchains, you can basically do anything with a hard fork. In the case of private blockchains, you will have a much easier time getting consensus for a hard fork, perhaps as easy as the authority running the blockchain dictating that everyone must accept an upgrade. The genesis block is hard-coded into the software. To re-assign a later block to be ...


1

In the recent technical steering committee meeting of Hyperledger they discussed the planning for an initiative to connect across multiple cloud providers, to demonstrates that Fabric can be deployed to multiple cloud platforms and integrated into a highly distributed and heterogeneous consortia network. This effort (as of the time of writing) is under way ...


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