Bitcoin Forum
January 16, 2019, 07:31:35 PM *
News: Latest Bitcoin Core release: 0.17.1 [Torrent]
  Home Help Search Login Register More  
  Show Posts
Pages: « 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 [23] 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 ... 549 »
441  Bitcoin / Development & Technical Discussion / Re: How to find the block header ? on: March 13, 2018, 04:28:26 PM
I made some changes in chainparams.h of bitcoin core and I am trying to create genesis block. I have genesis block hash and merkel root but debug.log says hash too high

What I am actually trying to do is compare the target value with hash of genesis block header.
You have to actually mine the genesis block. You can do that with a while loop in chainparams.cpp that calls CheckProofofWork (with some modification). Or just use a script like to do it for you.
442  Bitcoin / Development & Technical Discussion / Re: Genesis hash again on: March 13, 2018, 02:58:05 PM
Just knowing those 5 things is not enough to construct the block header. Furthermore, knowing the merkle root means that there is no need to know the phrase or the pubkey; those are part of the coinbase transaction which is part of the merkle root.

In addition to the nonce, time, and merkle root, you also need the nBits, the block version number, and the previous block hash. For the genesis block, it is version one, nbits of 0x1d00ffff, and previous block hash of 0000000000000000000000000000000000000000000000000000000000000000. Following the format for the block header, you get a block header of 0100000000000000000000000000000000000000000000000000000000000000000000003ba3edf d7a7b12b27ac72c3e67768f617fc81bc3888a51323a9fb8aa4b1e5e4a29ab5f49ffff001d1dac2b 7c. This is then hashed with SHA256d to get 6fe28c0ab6f1b372c1a6a246ae63f74f931e8365e15a089c68d6190000000000 which is the block hash. It is interpreted as a little endian 256 bit integer, and displayed as a big endian 256 bit integer so you get 000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f. Note that the hash is always in little endian byte ordering when used in other block headers.
443  Bitcoin / Development & Technical Discussion / Re: (Alpha Elements) Sidechains - state of the art? on: March 13, 2018, 02:48:10 PM
Just wondering if this project is under rework? I tried to get involved via the link on the webpage, but the link to the slack channel seems dead: (At least my Safari is showing as "could not connect").
Also the Freenode IRC: #sidechains-dev is very quiet, no info since last November in the web archives.
AFAIK not many people are doing stuff with sidechains so it's fairly quiet. Elements is still being worked on, I don't know what the current state of it is.
444  Bitcoin / Development & Technical Discussion / Re: How to find the block header ? on: March 13, 2018, 02:44:57 PM
Assuming that you are running Bitcoin Core, you can use the getblockheader command to get the block header for a given block hash. To get the raw block header so you can hash it, you would do
getblockheader <hash> false
445  Bitcoin / Bitcoin Discussion / Re: Bitcoin Core 0.16.0 Released on: March 13, 2018, 01:55:54 AM
I heard that it was possible to print coins without transaction fee with Bitcoin core, is that true? In the documenation it says minimum tx is 1000 satoshi
What do you mean by "print coins"? Anyways, such questions are off topic for this thread.

Can it work on ubuntu?

And if it can is there and special settings?
Special settings for what?
446  Bitcoin / Development & Technical Discussion / Re: Does Ledger Give Different Extended Public Keys for Segwit and Legacy Addresses on: March 13, 2018, 01:54:22 AM
Yes. The xpubs are derived from your seed at different paths, so they will be different.
447  Bitcoin / Bitcoin Technical Support / Re: Corrupted wallet.dat file on: March 12, 2018, 04:47:23 AM
First of all, do not necropost (posting in topics that have not had a post in a long time), especially with your own issue, not an attempt to help the OP. I've moved your post into its own thread.

I need help with a QT ver. 4.8.5 wallet.dat that is corrupt somehow.
Bitcoin Core is not called Qt, and the Qt version is completely irrelevant. What is the version of Bitcoin Core (which is not Qt).

#1  trying to replace the wallet.bat file into the same dir but keeps failing and just hang
    at "Loading block index" then no more.
How do you know that it is hanging? Sometimes Bitcoin Core can take a long time to start up, but that does not mean that it is hanging.

#3  remove all files except all the dll's and the config file
    and restart, starts fine but all frome day 1. (sync and no Bal)
Of course there won't be a balance, the blockchain isn't synced yet.

#5  replace wallet.dat while wallet running... a program error pops up
    and locksup the wallet completely.
Don't do that, you'll end up corrupting things further. You cannot just remove and replace files while they are still in use by the software.

Please post the contents of your debug.log file.
448  Bitcoin / Development & Technical Discussion / Re: Can hardware wallets suffer from ransomware? on: March 12, 2018, 04:42:55 AM
But I thought about it... can hardware wallets get encrypted by ransomware?

Hardware wallets ONLY execute things from their firmware; you cannot get a hardware wallet to execute arbitrary code (barring some major vulnerability). Furthermore, hardware wallets are not just generic storage devices, so a computer infected with malware can't read or write arbitrary data to a hardware wallet as it would with any normal storage device.

Some hardware wallets (like the Ledger Nano S) have apps that can be loaded onto the device to run things. If the app were malicious, maybe it could do something which is like ransomeware. However apps are isolated within the device itself (at least for the Ledgers) and don't have access to read and write arbitrary data to and from the devices internal memory (barring some vulnerability).

or there are some at least theoretical ways to get inside the device with some malware?
In theory, if the user is incredibly stupid, some malware could flash a new firmware to the device (which requires the user to push physical buttons on the device itself in order for a new firmware to be flashed) which then results in the stored seed being stolen. In practice, no, there isn't.
449  Bitcoin / Development & Technical Discussion / Re: When first run the wallet, connect to seed nodes, then? on: March 10, 2018, 07:06:44 AM
Then it means DNS seeders has automatically updated by connected clients, fetch its ip address, and record and add it to seeder's own file, become bigger while time goes?
Yes. The DNS seeders maintain their own databases of nodes and have their own crawlers. They crawl the network to find nodes. Of course nodes are removed from the database as nodes drop offline so it doesn't grow infinitely big.

And about how to setup DNS seeder, this is valid?
Looks like it is.
450  Bitcoin / Development & Technical Discussion / Re: When first run the wallet, connect to seed nodes, then? on: March 09, 2018, 05:00:30 AM
Bitcoin Core uses a thing called DNS seeders. These are not websites; they don't serve HTML. They are just special domains where asking for the domain's DNS records (i.e. resolving the domain name) will return you the IP addresses of several nodes that you can connect to. These nodes are then connected to get more IP addresses to connect to.

If the DNS seeders are offline, there are a set of hard coded seed nodes as well. The same thing is done with the hard coded seed nodes as with the ones returned by DNS seeders. The only reason to use DNS seeders is that they are more up to date and accurate. Hard coded seeds are only set prior to release, so they could be outdated.
451  Bitcoin / Development & Technical Discussion / Re: Mainnet-node and testnet-node on the same server - how? on: March 09, 2018, 01:36:31 AM
Renaming a program is not going to change the behavior of the program, which is what you want to do (change it from using mainnet to using testnet).

To start bitcoind in testnet mode, use -testnet.

That they use the same bitcoin.conf file is known, you can use the -conf option to choose a different config file for one of your nodes.
452  Bitcoin / Development & Technical Discussion / Re: Idea: Transaction propagation optimization on: March 09, 2018, 01:28:39 AM
Your proposal is not all that new, it's very similar to BIP 37. BIP 37 uses bloom filters to allow a node to only receive transactions that the node wants. It is specifically used by lite wallets in order to avoid downloading the entire blockchain. However BIP 37 has its downfalls; specifically it is computationally expensive for the full node serving the data, and it does not preserve privacy well (an issue specific to wallets).

However, there is one problem with your idea: what do you choose to filter? And with a filter, how do things not in the filter get transmitted through the network to the miners? How do you guarantee that someone will relay your transaction? The flood protocol practically guarantees this. But having everyone filter out transactions to relay would result in a lot of transactions being missed and thus not relayed.
453  Bitcoin / Development & Technical Discussion / Re: Lightning - Question to understand atomic transactions over the network on: March 09, 2018, 01:23:26 AM
I understand the network like this.

1) Sender is searching the best route through all nodes to reach the target.
2) Sender is encrypting the selected route node by node (onion routing)
3) Sender send coins to the first node using a payment channel between sender and first node
4) The next node decrypts the follow up node and continue sending coins to the next node over the next payment channel
5) continue with 4 until the target node is reached.

In my understanding, whenever I send something over the payment channel, this transaction is completed and not reversible (this is maybe the point where I'm wrong).
So, when I have 10 nodes in my selected route, and node 5 in my list is down. How does the network make sure, that the 4 nodes before are doing a rollback to give back the coins to the sender, so the sender can try a different route.
That's not how payment routing actually works. That's just the messaging protocol to transmit some information between nodes.

The actual payment part works through Hashed Time Locked Contracts (HTLCs). So node A offers a HTLC output to node B. In order for node B to spend from that HTLC (thus being paid by node A), he needs to provide the preimage to some hash in addition to his own signature. After some timeout, node A can take the money back with a signature of his own.

In LN, the HTLCs are used to make the payments between the nodes. They use the same hash so they all have the same hash pre-image required. So if any one HTLC is spent, all HTLCs in the route can be spent since the hash pre-image is revealed during the spend. If the hash preimage is never revealed, then the coins are never sent to the other party. This makes it atomic.

As a shortcut (to avoid on chain transactions for each HTLC) LN uses the onion routing method you described. The hash preimage is given to the recipient by the sender and that is transmitted to each node in the route so that they all have the hash preimage. Once both nodes in the channel have the hash preimage, they resolve the HTLC off chain. If some nodes are not able to transmit the hash preimage to settle the HTLC off chain, then the node that was able to settle with one peer but not the other can settle on-chain, and in doing so, reveals the hash preimage for the remaining nodes to settle (either on chain or off chain, as necessary). That node is incentivized to settle on chain because he would actually be losing money by not settling.
454  Bitcoin / Development & Technical Discussion / Re: Odd questions, what I am missing? [RPC call] on: March 09, 2018, 01:06:34 AM
1) As far as I know and can see it should do name resolution, but since this is the 1st time I am actually doing it this way does it, or am I just assuming that it does?
You are assuming that it does name resolution, but AFAIK, it does not. Just because a different software does name resolution (indicating that the machine is capable of doing so) does not mean that bitcoin-cli will do name resolution.
455  Bitcoin / Development & Technical Discussion / Re: Setting up a private chain/testnet : reverse engineering the blockchain code on: March 09, 2018, 12:57:20 AM
The consensus rules are what define a blockchain. You cannot create a blockchain without the consensus rules. You need to implement your consensus rules in a software that is then used to create a blockchain.

Typically people who are doing this will just clone an existing coin and modify it. You will need to understand how that coin works and what your modifications must be. This isn't something that is beginner friendly nor is there a beginner "how to do" guide available. This is specialized knowledge that not everyone can do.
456  Bitcoin / Development & Technical Discussion / Re: Why per-wallet db.log and database? on: March 09, 2018, 12:48:20 AM
Both the file db.log and the directory database are files used by the BDB database engine. The directory database is a temporary directory that is used to store data about the wallet while the wallet database is open. If Bitcoin Core is uncleanly closed, the BDB database will also be uncleanly closed. If it is uncleanly closed, then in order to open it again without having any problems, you must have the database directory as it contains some BDB state data. If they are separated (wallet.dat moved out or database is deleted), then the wallet database can be corrupted and private keys corrupted. This can result in a loss of funds.

Having separate wallet directories containing their own database environments allows for better dynamic wallet handling and a failure to close the BDB environment cleanly may only just effect one wallet instead of all wallets.
457  Bitcoin / Bitcoin Technical Support / MOVED: CEX.IO SCAM? or Any suggestion?? on: March 07, 2018, 04:44:33 AM
This topic has been moved to Trashcan.

458  Bitcoin / Armory / Re: Haven't received a payment to armory? on: March 06, 2018, 02:44:40 PM
What version of Bitcoin Core are you using?

Try updating Armory.
459  Bitcoin / Development & Technical Discussion / Re: Has anyone got a link to Satoshi's first implementation of Bitcoin? on: March 06, 2018, 02:39:07 PM
Some of the early distributions (code and compiled binaries) are available here:
460  Bitcoin / Development & Technical Discussion / Re: What do you think of this change on the GUI on: March 04, 2018, 06:14:58 PM
What's the input size for non-Segwit P2SH?
It depends on the script wrapped by the P2SH address. It could be 0 bytes, or it could be 10000 bytes (the maximum scriptsig size).
Pages: « 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 [23] 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 ... 549 » is not available or authorized for sale. Do not believe any fake listings.
Sponsored by , a Bitcoin-accepting VPN.
Powered by MySQL Powered by PHP Powered by SMF 1.1.19 | SMF © 2006-2009, Simple Machines Valid XHTML 1.0! Valid CSS!