The information i have written was regarding gathering information using blockchain.info's API.

If you want to use your daemon, you can write a small script.


Simply edit your bitcoin.conf file and add blocknotify or walletnotify (depending on what you need):

walletnotify will be called if:
1) You receive a transaction to one of your addresses
2) First confirmation of a TX to one of your addresses
3) You send a transaction

blocknotify will be called each time you receive a new block.


Then you can do whatever you want and implement any logic/logging in script.sh and script2.sh.

This is not correct.

The lightning network is a second layer scaling solution.

The amount of transactions which fit into a block will not be increased. Neither will the TX fees directly be reduced.
The LN will give you the ability to (1) fund a channel with a standard on-chain transaction, (2) make multiple off-chain transactions with insignificant fees, (3) close a channel with a standard on-chain transaction.

This gives you the opportunity to make trustless instant transactions on the LN without paying the on-chain fees.
It is not directly changing bitcoin. On-chain transactions work the same as before. It is an additional layer on top.

A pretty decent description of the lightning network can be found here.

If you would manage to compromise 51%+ of ASICs, how would you maintain the full control over them? What would you try to 'destroy' the network?
Regardless of what you will do with those ASICs to attack the network, it will be WAY LESS profitable than just using them for mining (or destroying them to increase the actual percentage of 'own' hashrate) while you have control over them.




If bitcoin would suffer a 51% attack maintained over multiple hours, the whole cryptomarket would drop in value.
An attacker couldn't 'move on' to the next coin. They all would be worthless. The altcoins would be crashing first, followed by BTC.

This additionally assumes an attacker is able to cash out in a timeframe between the 51% attack and the markets reaction to such an attack, which does not necessarily apply.

I am not Mocacinno (even tho i love drinking them), but i am still going to answer your question  


Each address owned by bitfinex is 'directly' owned by bitfinex. They just provide their address to a user to deposit to.

It (most probably) is a deposit address, since the concept of a 'mixing address' is unnecessary. It doesn't bring any benefits, just more TX's -> More fees.

The withdrawals from this address about 10-60 minute after deposits do also indicate that it is a 'deposit' address (which is being used to withdraw other customer).

There are a lot of (almost) perfect wallets available.
There are advanced wallets with intuitive UI (e.g. electrum) and very straight-forward wallets (e.g. andoid: mycelium).

But even secure wallets can be easy to use. Take ledgers application for example. It is very easy to use. Thats really not a proper reason to leave coins on an exchange.

If you are buying because you believe in bitcoin or want to use bitcoin, you should also be able to understand a simple wallet application.
If you are buying BTC because of getting rich over night.. well.. Those people WILL lose their coins sometime in the future.




A developer is not responsible for the stupidity of a user.
There are enough wallets which are easily understandable. If one can not figure out how to use a simple wallet, he should maybe not own cryptos at all.

If you are receiving such a high amount daily, you might consider buying a hardware wallet.
This way an attacker would have no chance to get access to your coins or private keys.

Until then, you might install a wallet on an offline-machine (e.g. electrum on bootale USB linux distro) and receive your payments there.
And definitely do what Lucius said and run a malware scan.

Sorry, but this IS correct.

A consensus algorithm is completely independent from scaling/blockchain itself.
The consensus algorithm basically just describes which block is being accepted/valid. It has no influence on scaling, neither on the amount of transactions.






 
What do you think could have been chosen except from PoW? PoW definitely was the best option to choose from.




You seem to misunderstand the utility of the consensus algorithm. The design of the consensus algorithm has NO IMPACT on the transaction-/blockchain- size or the amount of TX's being processed within a timeframe.

Wow.

'Hash rate' is completely irrelevant when sending a transaction.
It is being talked about hash rate in context mining or network strength.

Additionally there is no 'priority'. Some wallets may display a 'priority' calculated from the fee.
However, a priority does not exist. If you want to get your TX confirmed faster, send a higher fee. But sending a fee which is higher than the recommended for 1 block would be a waste.
Check this site and this one to choose the correct fee.


The time it takes for a transaction to be confirmed only depends on the (1) amount of transactions in the mempool and (2) your fee compared to the other TX's fee. And of course on the (3) time it takes for a miner to find a block.

Thats the same thing which makes me feel quite uncomfortable when accessing my nano s.
It just doesn't feel right to install google chrome and use a chrome application to access your cryptos, especially on linux  

I am definitely looking forward to use ther native application. For BTC we can use electrum to bypass the usage of chrome.
But there aren't proper wallets available for other coins (e.g. ETH). And im not a big fan of MEW :7


Lets see how long it takes until the application is released and how long the 'future releases' with additional features will take.

The ledger nano (HW.1) was based on a smartcard (ST23YT66) with USB support.
However, it is not being maintained or (officially) sold anymore.

Their maintained product, the ledger nano s, is based on the ST31H320 Secure element, which does differ entirely from the HW.1 architecture.
This secure element doesn't even support USB/Displays. Thats the reason ledger uses a second microcontroller (STM32F042K6).
This was the attack surface used by Saleem Rashid when finding a vulnerability in their architecture.

Coinbase can NOT be considered a safe and secure wallet.


All you basically own when using such a service is some digits in their database tied to your account..

---

The transaction fees require are completely independent to the wallet you are using.
Each (proper) wallet gives you the possibility to choose an estimated or set a fixed fee for your transaction.

Did you check whether you have the correct wallet file opened on your offline machine?

You might also try to look at the addresses. Does your offline wallet contain each address used in your transaction?
If you can not find those addresses in the address tab, you might try to create another bunch of key pairs with this command (in 'view' -> 'show console' -> 'console' tab): for i in range(5): createnewaddress()

For your coins to arrive properly, just create a transaction to the correct address provided by the receiver.
Nothing else is required on your part.

It doesn't matter whether you are using P2PKH (what you might be refering to with (a) ?) or P2SH.

No, this does not work.

It is not possible to calculate the seed (or the mnemonic code) out of one or multiple private keys.
The child-private-key-derivation function does use HMAC-SHA512. The only option would be to bruteforce it, which is practically not possible (2²⁵⁶ is too large to bruteforce).

It depends.

If the outputs are in P2PKH format, then yes. If both (different) public keys do match the same hash this is possible. That would be a hash collision.
If the outputs are in P2SH format, then no. Since it is not possible for two different private keys resulting in the same public key, which would be required to be able to successfully redeem them.

24 Words would indicate it is from a BIP39 wallet.

You might try out to import this mnemonic seed into electrum (https://electrum.org/#download).
Choose 'I already have a seed' and enter your words. Make sure you edit the settings and tick 'BIP 39'.

The derivation path depends on the wallet you have used when creating this seed / addresses. Did your address start with a 1.. or with a 3.. ?

In the first step you are creating new UTXO's. For someone to use this UTXO, he has to meet conditions inside the script of the UTXO.
If i then want to create a new transaction with this UTXO, i have to supply a corresponding screept that meets these condition (e.g. scriptSig). This requires to reveal the public key and using the private key to sign.




Yes, thats correct.




Coins arent really assigned. They exist as unspent transaction outputs (UTXO).
To claim the ownership and combining their value into new UTXO(s), you have to prove ownership.

Pay to public key hash (P2PKH) does require to create a script: OP_DUP OP_HASH160 <pubKeyHash> OP_EQUALVERIFY OP_CHECKSIG.
To spend these coins you have to provide the public key and a matching signature.

A P2SH UTXO does include the hash of the spending condition (instead of the condition itself).
To spend these coins you are providing the redeem script itself, which is then being checked and evaluated against the redeem script hash during a transaction.

Your example actually isn't an 'example' for discarded blocks, since Miner2 is the only one who does create a valid block (1. - 6.).
Since TX2 has never confirmed in your example, all nodes which did receive TX2 still relay it and keep it in their mempool.
Whether Miner2 does decide to (maliciously?) ignore Tx2 doesn't matter. It will still get relayed through all nodes (and therefore also every miner) in the network.




IF Miner2 did include Tx1 into the block he has created in 5), then yes.

No. A 'wallet' is simply a piece of software which handles private-/public- keypairs.


When creating an 'address' your doing it this way:

1. Create random number (private key)
2. Calculate public key out of private key
3. Hash the public key with RIPEMD-160(SHA256(public_key)) = Address

Now, theoretically there are 2^96 different private keys which do all 'create' the same address (on average).
This means that it is theoretically(!) possible to create two different private keys, which do refer to the same address. (Practically this won't happen, ever.)

Note that addresses do NOT exist on a technical level. They are just an abstractions for us humans making it easier to read.


Coins can not be send 'to a wallet'. The UTXO's are being assigned to public keys. And you will be able to spend these UTXO's using the corresponding private key.

You broadcast a transaction which will be in the mempool of the nodes until a miner decides to include your transaction into a block.




Blocks are not 'mined into the blockchain'. Mining simply means to create a valid block.
If 2 blocks get mined at the same time (very uncommon, but possible), the NEXT block will decide which one is valid.
The longest chain is the actual valid blockchain.

Small example:
Miner A and miner B do mine block nr. X at the same time. They both broadcast it into the network.
A portion of the miner in the network did receive block X from A and are trying to build the next block upon this block.
Another portion of the miner did receive block X from B and are trying to build the next block upon this block.

Now, miner C (who did mine using block X from A) found a block (X+1) and shares it.

The whole network now accepts this chain (Block X from A --> Block X+1 from C) as valid chain since it is the LONGEST valid one.
Block X from miner B will get discarded by the nodes.




A transaction is not 'marked' as mined. Blocks are being mined (created).
A transaction is being confirmed by being included into a block.

So, once a block is being mined which includes your transaction, it is considered as a confirmed transaction (Amount of confirmations = 1 + Number_of_blocks_mined_after_your_TX_got_included).