This is a technical article that assumes a working knowledge of Bitcoin.A full node, such as Bitcoin Core, knows the following:This requires a lot of data to be downloaded, stored and indexed.However, there are some shortcuts that reduce the amount of redundant information if you don't need a complete block chain.SPV provides a way where you can determine that a particular transaction was in a block in the block chain without requiring the entire block chain to be downloaded.It does this as follows:A Merkle tree is a mathematical model where the block is at the apex and all the transaction get placed in a tree-like structure.A Merkle tree proof is a list of all the hashes between the apex (block) and the leaf (transaction).The point of a Merkle tree proof is that you only need a small part of the block to prove the transaction is in the block.Thus when a wallet says it uses SPV it means that before it believes in a transaction it checks:The transaction is then "good" and will be added to the wallet.Many people have asked us about why we only support HD accounts (namely Account 1 in the normal parlance).The main reason is due to how we get our transactions from the Bitcoin Core nodes.

We use a technique called bloom filtering.We don't ask for the transaction directly, instead we give the Bitcoin Core nodes a filter that we know will match all the transaction we are interested in (plus some false positives to put anyone spying off the scent a little).Supporting just one account means creating filters for a steadily increasing number of addresses for both the main addresses and the change addresses.This starts off as "hundreds" and, as the wallets get used, will become "thousands".Scaling this up to supporting any number of accounts means creating filters that match:number of accounts x (main addresses + change addresses)Thus we have to filter to match many more addresses to the point (we think) where we are pretty much getting the complete blocks.bitcoin vor und nachteileThis makes us as at least as slow as a Bitcoin Core node and more likely slower as we are uploading very wide bloom filters.We think this will be far too slow to be useful so we are restricting our usage to a single account.We don't have access to the Unspent Transaction Output (UTXO) set using Bitcoinj thus we cannot check directly against it.38 gh/s bitcoin

Only implementations that have a full block store in their backend - and can query it directly - can use the UTXO set which would mean downloading the entire block chain.Bitcoinj only talks the Bitcoin network protocol which does not support features such as "give me all the UTXO for this address".To reduce the amount of blocks that need to be downloaded we include a checkpoints file in the installer which contains the headers of each block when the Bitcoin difficulty level changes (every 2015 blocks).This allows us to only sync from the checkpoint before the wallet birth date which saves a lot of time and is why we ask you to record the "datestamp" during wallet creation.linux bitcoin mining osThus if the wallet datestamp is equivalent to block 200,050 and we have a checkpoint at block 200,000 then we can just sync 50 blocks.Since the checkpoints file is stored locally and is provided through our installer it enables us to detect when a Bitcoin node is attempting to spoof the use of their forked chain (containing fake transactions) rather than the genuine Bitcoin block chain.MultiBit HD will automatically connect to a Bitcoin Core running on localhost if it can detect one.mine litecoin program

It also connects to other nodes since we use transaction propagation to determine when a transaction has been sent properly and when the change from a transaction can be used.If we relied purely on a single node (even if it was trusted) we could not have confidence that the real external Bitcoin network is relaying it.Here are some related articles:_ Here's how it works: Anybody can ask a question Anybody can answer The best answers are voted up and rise to the top up vote 1 down vote favorite 2 If you would compare Bitcoin with electronic banking there are quite a lot of similarities like the encryption and hashing with private and public keys.ethereum mining difficultyIn electronic banking though the bank is the certification authority.bitcoin kickassWho is doing this in blockchain/Bitcoin?

blockchain network trust up vote 1 down vote Depending on what function of the certification authority you are looking for, Bitcoin doesn't need one, or the blockchain does it.Identity in e-banking vs identity in Bitcoin network Electronic banking relies on the communication between bank and customer being secure which is what they use encrypted protocols for.They don't use either hashing, nor private and public keys in any similar fashion as Bitcoin.Actually, when you order a payment through e-banking, you have to reveal all the secrets to the bank to authenticate yourself: E.g.you put in your user name, your password, and then a specific one-time code as requested by the bank, or when using a credit-card, you give name, credit card number and security code.As these pieces of information would be sufficient to hijack the payment in a man in the middle attack, communication needs to be secure and encrypted.To that end, a certification authority gives out "passports" that allow you to make sure you're talking to the right entity.

On the other hand, communication in Bitcoin is authenticated by the content of the message itself.When you order a payment, it includes a signature that could only have been created by the owner of the address that held the money previously.Nobody can change the message, because the signature would be invalid for any other message, and they cannot produce another valid signature without having access to the private key.The secret is not revealed to order the payment.Therefore, it is not necessary to encrypt communication within the network, and also there is no need to certify the identity of network participants.One can tell directly from the message whether it is valid or not, making the identity of the source of the message irrelevant.Authenticity of payments in e-banking vs Bitcoin network In e-banking only the bank and you know your balance.Therefore, when you order a payment, the bank will check their ledger and confirm the payment.In Bitcoin, everyone can check whether a balance is available to be spent.

As explained above the transaction order itself can be checked for validity by every participant, so it is impossible to spend money that isn't yours.The blockchain keeps track of the balances, therefore becoming the ledger everyone referring to when checking payments.Yet, the blockchain is extended in a decentral process, so while the blockchain is central to the network, it is maintained decentrally.Where e-banking and Bitcoin are similar The one thing that still can be attacked in the same way in Bitcoin as in e-banking is the other side of the payment: People can try to fool you into paying something that you didn't intend to pay for.You still need to figure out where to send money.That's where Banking and Bitcoin have the same vulnerability to phishing sites.In fact, Bitcoin is a bit at a loss there, because once you've sent the money it's gone, while you may have a recourse through your bank by having them reverse the payment.Did you find this question interesting?Try our newsletter Sign up for our newsletter and get our top new questions delivered to your inbox ().