texts: Is "volume" the quantity of BTC exchanged, or the number of trades completed?

texts:
Suppose the following trades happen

Trade 1:   100 BTC  @ $75
Trade 2:   0.5 BTC  @ $76
Trade 3:   100 BTC  @ $77
Trade 4:   100 BTC  @ $78
Trade 5:   100 BTC  @ $78

Five individual trades occurred for a total of 400.5 BTC.  There was a total of 200 BTC acting as a wall at $78.  Similar to how I monitor the trade wall at mtgoxlive.com, I'd like to determine if the "wall moved" or if the "wall was eaten"/traded.

I'm trying to gather that information from the MtGox website and not sure if they display the count of individual trades, or the BTC sum.

Here, in the top level drop down menu Volume:75584 BTC however in the drop down graph I see volumes that range in 1,000 to 3,000 total.  In the most current example I see a volume 17,261 of something (either trades, or BTC, I'm not sure)

It seems that volume is measured in two ways, but with the same word:

The quantity of BTC shares (and fractional units) traded
The quantity of trades taken (a whole number)

Since MtGox seems to overload the meaning of "volume" in the two instances, where can I find a more accurate representation / graph of each interpretation of "volume"?


texts: Updating a lightning node to latest version

texts:
I'm running a lightning node on a Raspberry Pi. I'm still learning about the technology and linux as well. But I'm not sure how to securely update my node to the new LND version 0.4.1 and I'd like some directions.

I already downloaded LND binaries and checked the keys.

$ wget https://github.com/lightningnetwork/lnd/releases/download/v0.4.1-beta/lnd-linux-arm-v0.4.1-beta.tar.gz

I used this to install the previous version (0.4-beta)

$ tar -xzf lnd-linux-arm-v0.4-beta.tar.gz
$ ls -la
$ sudo install -m 0755 -o root -g root -t /usr/local/bin lnd-linux-arm-v0.4-beta/*

But how should I proceed if I just want to update, considering I'm not installing from scratch? What commands should I use? Should I backup anything before doing this (like channeldb.db)?


texts: Get bitcoins to self created Bitcoin address

texts: I created Bitcoin private and public key pair for Bitcoin. I am looking a way to receive funds to my Bitcoin address. The wallet apps which support buying or selling bitcoins are generating bitcoin addresses again. How can I buy bitcoins to my own account instead of wallet generated addresses?


texts: How is mining profitable if a $10.000 ASIC will generate like $63.23 per month?

texts: This $10k ASIC miner has 1TH/s and by this hashing calculator (I know they're not THAT precise but...) it'll generate like $63.23 per month? Why would anyone invest in this?


texts: Difficulty target representation in bitcoin wiki

texts:
The bitcoin wiki describes difficulty target representation as follows:

How is difficulty stored in blocks? Each block stores a packed
representation (called "Bits") for its actual hexadecimal target. The
target can be derived from it via a predefined formula. For example,
if the packed target in the block is 0x1b0404cb, the hexadecimal
target is
0x0404cb * 2**(8*(0x1b - 3)) = 0x00000000000404CB000000000000000000000000000000000000000000000000
Note that the 0x0404cb value is a signed value in this format. The
largest legal value for this field is 0x7fffff. To make a larger value
you must shift it down one full byte. Also 0x008000 is the smallest
positive valid value.

Why 0x008000 is the smallest positive valid value?


texts: Why transactions' average confirmation times becoming more chaotic?

texts: According to this chart, Bitcoin's transactions' average confirmation times are varying much more widely than they were a year ago. Why would this be? Is it because the daily transaction rate has been increasing?


texts:
Once a day, roughly, two competing blocks with the same height are mined, which leads to one of them being orphaned.

Was there ever a "natural" case in which the fork lasted for two rounds? By natural I mean a fork that was not created by any bugs such as the one in March 2013 ( https://bitcoin.org/en/alert/2013-03-11-chain-fork ).

What was the longest fork?

A naive back of the envelope estimation says that it should happen once in 100 days, under the assumption that half of the network heard about each of the competing blocks first. Therefore, a more realistic estimation would be once in a year or two.


texts:
On the bitcoin wiki its says:

  Transactions need to have a priority above 57,600,000 to avoid the enforced limit (as of client version 0.3.21). This threshold is written in the code as COIN * 144 / 250, suggesting that the threshold represents a one day old, 1 btc coin (144 is the expected number of blocks per day) and a transaction size of 250 bytes.

Meaning 1 BTC need 1 Day to become medium priority and will need no fees. On testnet I collected a few coins and checked the priority in bitcoin-qt client. It grows from low to low-medium to medium. Then it stops. While now on 570 confirmations it should be way higher than medium priority. Checking the bitcoin-qt sourceode there are more priorities deposited.

Did I missed something?


texts:
Can someone explain benefits of using p2pkh, p2sh, bech32, p2sh-p2wpkh, p2wkph, p2wsh.. and so on

from what I know, bech32 is most recent, but what would you say is the best?


texts: Bitcoin account balance computation power

texts:
As far i know, In bitcoin there is no where storing the account balance in db straight forward. If the person wants to know his account balance from his client app the server will calculate all his transaction of credit and debit return the sum value.

If this above is true when person A has previous transactions like 20,000 and Person A wants to transfer some money he has to Person B.

When this process starts the bitcoin mining server has to calculate all his transaction from beginning to check whether the person A has enough balance or not and this has to be done in other mining server also to verify.

In this case as long as the person has 1 lac transaction, to calculate the balance the computation process will be heavy right ? more computation process uses more cpu cycles and power which affect the maintain cost of the computer and transaction fee may go high.

Please explain how its happening ?


texts: How to get difficulty for Bitcoin and other coins

texts:
How do I get access to the latest Bitcoin/Altcoin difficulties from the original "source/network"? I want to develop a C#/.NET application that collect this information.

I know that there are web sites that provide information about Bitcoin and Altcoin difficulty. Coinchoose and Coinwarz provides JSON APIs for example. There are also blockexporers like http://blockexplorer.com/q/nethash/2016 that could give me the current Bitcoin difficulty.

The problem with Coinchoose and Coinwarz is that they are not complete, not fully real-time and Coinwarz cost money in addition to that. The block explorer above is for Bitcoin only. Are there block explorers for all AltCoins as well? And are they all providing different API's?

There must be some "original source", like the mining network or similar, where you can connect and get this information in real-time? Or is that also completely different for each coin? I understand that each coin has its own mining network, but are they different except having different IP-addresses for example?

So the question is basically how do I get access to real-time coin difficulty information for Bitcoins and all other coins - not from an existing web site, but more on the API / programming level?


texts:
Why don't we implement a Node Operator reward program (in the core) or if such implementation ever existed what would be the overall (Downside,Cause for concern, etc)

Why don't we use the Miner Fee Reward to pay the Nodes for instance? Without talking about the overall economic implication but more the technical side of things.


texts: Are the miners concerned with what the pool operators do with their hashpower?

texts: I've stumbled upon a few posts on the Bitcoin forum about miners claiming that they don't care what the pool operators do with their hashing power as long as they are paid, and some others that are more concerned than that. Is the bulk of the miners concerned with what the pool operators do with their hashpower?


texts: Import a wallet generated by another website to my node?

texts:
so I have a wallet generated by some other website, I have the address and the privkey.

I want to get that wallet imported & all it's previous transactions into my full node, I am using Bitcoin Core.

How can I do such a thing?

Thanks


texts: How to Call JSON-RPC SendToAddress when the Wallet is Encrypted?

texts:
I'm using JSON-RPC to send commands to my bitcoind, and it works fine.

Now I want to encrypt my wallet. When I've done that, I will need to send the passphrase when calling SendToAddress. How do I do that?

Right now I send these parameters:

address
amount
comment
commentTo

which are put into an array in the order above.

Will the passphrase be another parameter that I append as the last element in that array?


texts: Is there a technical reason for which there isn't an option in Bitcoin Core that would deploy an internal Electrum Server, or something similar so that a software wallet can fetch addresses and balances?


texts: Bitcoin wallet for Symbian operating system?

texts:
Can I use Bitcoin on my Nokia N97 phone which uses Symbian OS?

I cannot find any Bitcoin wallet applications on Ovi store :-(

I have found a wallet client for the Android operating system but that is hard to install on my N97.

I'm willing to compile a client from sources, but I can't find any. I've tried SourceForge but to no avail. Any suggestions?


texts: Are there Bitcoin users in Asia especially Southeast Asia ? I'm from Malaysia

texts:
Are there many users of Bitcoins in Asian countries ?  I am from Malaysia.
If there are, I would like to give it a try too.


texts: How do I find the txid and vout values for an input I want to spend?

texts:
I was in the http://coinb.in/multisig/#newTransaction and wanted to make a input but it needed 2 values.

Txid, How do I get that?
TxIn/vout, Whats that and how do I get that?


texts: Read only blockchain in bitcoind , patch ideas

texts:
This question is related to to the ( already nearing 2 GB and always increasing size ) blockchain download needed to use the bitcoin network, and is referencing this previous question :
Is "Reclaiming Disk Space" already implemented? How effective will it be?
 Please read it before answering

Currently if I have bitcoind running on 20 machines, or 20 bitcoind running on the same machine, each of them need to download and store 2 GB blockchain, total 40 GB diskspace used and much bandwidth to dowload it 20 time.

I think the easiest way to make it better would be to have a "read-only" blockchain, one of the bitcoind writes it and the others only use it read only to check transactions.

This could be used to be my own trusted blockchain provider, for all my machines and bitcoind running, on the same machine or remotely using sshfs or other mounting options.

Now the questions :
1- How to implement this in bitcoind ? easiest way to do this ?
2- can this be a problem for the bitcoin network itself in any way ?

Rules : I dont want answers like "try poolserverj" or "you dont need that" please ;)


texts: How do wallets (like jaxx) pair with each other using the mnemonic seed phrase?

texts:
I'm a bit puzzled on how a wallet pairing process works.
I know you can restore you parent private key from a mnemonic seed phrase. This will give you a parent private key. Using this private key how does a wallet figure out the private/public keys you have derived from this parent key?

Thanks!


texts: BIP 37 automatic filter update not inserting outputs

texts:
I'm having a problem with bloom filters when using the getdata message.

As I understand BIP 37, setting the bloom filter on a connection using the loadfilter message with flag BLOOM_UPDATE_P2PUBKEY_ONLY set, the responding client automatically inserts all outpoints (TXID and output index) in the bloom filter of transactions matching the filter. However, when I attempt to do exactly this, the node only ever sends transactions containing outputs TO the address I am filtering for, never transaction that contain outputs FROM the address I am filtering for.

My approach is as follows:

Add the following public key to the bloom filter: 1JbFvyaMyHHmvvjc54h4YARq3uoX2ZZ4Qj (randomly picked)
Send the filterload message containing the filter (as seen in the wireshark snippet below).

Bitcoin protocol
Packet magic: 0xf9beb4d9
Command name: filterload
Payload Length: 261
Payload checksum: 0x2bb02c45
Filterload message
    Filter
        Count: 251
        Data: 000000040004010000000100000000000000020000400000...
    nHashFunc: 13
    nTweak: 0x1a689ff4
    nFlags: BLOOM_UPDATE_P2PUBKEY_ONLY (0x02)

Send the getdata message with the hash of all blocks containing transactions to and from the wallet (which I have identified on a block explorer for the purpose of testing this). The inventories are typed MSG_FILTERED_BLOCK.

The node responds with the following messages in order:

MerkleBlock: 000000000000000001201ab2679db7c87a432967c060596bad0ac093dac94111
Tx:......... 187b00588e8d7844c405da9a15d78dbd7ebb9b2887fb5aace6651719fede923e
Tx:......... dbbca0d839435ac77db65378a9607d17b0aa965f3027d84dcf0ee5115dc8d32f
Tx:......... 17c12f45956082a913c0c862d573cf067fa5ee96ba5b954914371da6bef51f7f
Tx:......... 36cce25d34a5da0f7d69253743eae7bb7c576e5543d0eb16db0f72967edb4bc6
Tx:......... 6ea48c6286b1691cd1ecec271a3f52a3fe099467bb6c926b41ba8942e21d4aa6
MerkleBlock: 0000000000000000049ee67931f6d4970a7d06b14b8aadd406223ab65efe5025
MerkleBlock: 0000000000000000019f3fc2c8da43e8a81373ae189ace4caec6c59969f46ff6
MerkleBlock: 000000000000000000f67dad206798db2e6c5dffec84d213397784be894e66fa

The 5 transactions in the list are correct, as the contain outputs targeting said wallet.
However, block 0000000000000000019f3... contains transactions with inputs from said wallet, but the merkleblock message of this block is not followed by these transactions.
Shouldn't the node add the outputs of these 5 transactions to the bloom filter, and thereby match the later transactions containing inputs pointing at them?

I have confirmed that the node is in possession of the relevant transactions.
If i load the filter manually, adding the outputs myself, this works as intended.

Am I misunderstanding how BIP 37 is used?


texts: Unexpected coinbasevalue in regtest mode

texts: Running a simple local setup with 3 nodes in regtest mode.  Getblocktemplate tells me the coinbasevalue = 25 bitcoins but the block height is only 202.  Shouldn't the coinbasevalue = 50 bitcoins?


texts: How transaction fees differ between different wallets?

texts: In particular, I'm wondering what is the difference (if any) of transaction fees between Bitcoine-core, MultiBit and blockchain.info?


texts: Does mtGOX allow for buying on one exchange and selling on another through their API?

texts: Can the mtGOX API be used to buy on one exchange and sell on another, if so, how? (An example api call/url etc would be great)?


texts: How are code changes (e.g. new features) to applications such as Bitcoin deployed and how is compatibility mainted?

texts:
How does Bitcoin deploy new features and manage different versions compatibility?

For example if a new feature is added to Bitcoin, how is that then deployed and managed? That is, how is everyone on the network not forced to upgrade when a new version is available?

If an upgrade/update is not forced, how does Bitcoin manage different versions of Bitcoin on the network? Is there a minimum required version somehow distributed amongst the network?


texts:
Are there anyone know how to convert P2SH address (like 34A5PyCvPJKYtHmj9jmKhGzBBwpGuAkZog) to MANDhrctLRAygo3dFckfWvEaWeQizSwWNK?

I tried to decode with Base58Check, then removed 05 and added  032, then encode it (Base58Check), however I got wrong result MANDhrctLRAygo3dFckfWvEaWeQiti143C


texts: How to run docker cointainer from kylemanna/docker-bitcoind on testnet

texts:
I have a bitcoin.conf.
It looks like this:

testnet=1
server=1
rpcuser=Ulysseys
rpcpassword=YourrrPassword
rpctimeout=30
rpcport=8332

Now I try to run a container from this image:

Create volume:

$ docker volume create --name=bitcoind-data

Create container:

docker run -v bitcoind-data:/bitcoin --name=bitcoind-node -d \
        -p 8333:8333 \
        -p 127.0.0.1:8332:8332 \
        -v /path/to/bitcoin.conf:/bitcoin/.bitcoin/bitcoin.conf \
        kylemanna/bitcoind -testnet

I go inside my container and check with bitcoin-cli getinfo:

{
  "version": 140200,
  "protocolversion": 70015,
  "walletversion": 130000,
  "balance": 0.00000000,
  "blocks": 0,
  "timeoffset": 0,
  "connections": 0,
  "proxy": "",
  "difficulty": 1,
  "testnet": true,
  "keypoololdest": 1503649077,
  "keypoolsize": 100,
  "paytxfee": 0.00000000,
  "relayfee": 0.00001000,
  "errors": ""
}

Testnet=true so that's okay but I don't see any log of data (docker logs container-name). Also my docker volume is still 17MB and 0 blocks.

What am I doing wrong?

When I load my bitcoin.conf in my bitcoin-qt on macosx it becomes green but remains on 'pending' to get the blockchain.

Is there something wrong with my config or is it maybe blocked on my network?


texts: Does anybody know how exactly to connect to Terraminer machine via USB?


texts: The question is basically in the title. Can I (or it is possible to) extract the chain code from a ledger nano s device? It doesn't have to be the Master Chain Code. Any of them will do.


texts:
are there any p2p markets for  different kinds of coins, like https://localbitcoins.com/ for bitcoins?

Thank you!


texts: Is anyone taking advantage of different prices across exchanges?

texts:
Say I have funds on two exchanges. Whenever the price of bitcoin is higher on the first one, I sell on that one and buy on the other one.

Is anyone doing this or has a program that does this? Is it even possible?


texts: Does Electrum require the Satoshi client?

texts: Bitcoin Armory is a client that sits on top of the official bitcoin client. Bitcoinj is a totally different client, separate from the official bitcoin client. Does Electrum also need the official bitcoin client, or is it separate?


texts: How does a recipient know they can satisfy the transaction script to spend their bitcoins?

texts:
The wiki page on the transaction script says:

  The party who originally sent the Bitcoins now being spent, dictates the script operations that will occur last in order to release them for use in another transaction

How does a recipient know they can spend the bitcoins they received? Would it be possible for a malicious user to create a script that the recipient could not use to spend the bitcoins, without them being aware of it? (Possibly due to a client UI limitation?)

The situation I'm describing would probably be unusual, as it would involve the sender deliberately sacrificing (and destroying in the process) bitcoins purely to spite the another party. Even still, is it possible, and what measures (could) protect against it?


texts: Is it possible to set up a rig in a location where you will only be once a few months, antminer. In summer temp may reach high 80s during day otherwise cooler temps... I wasn't sure what would go down if there is a power outage or if it gets too hot...


texts: Security within a deleting blockchain model

texts:
Assume a blockchain model that contained no transaction data - just pure data. After a set time this data would simply be deleted, and entire blocks would be removed. How would the security model of the blockchain suffer? Would it make it easier for a "long chain" attack, and if so how can this be prevented?

The idea is to store data into the blockchain. Anyone could store data in this chain, and all nodes have a copy of this chain. There is a block race, to secure the blockchain as normal, but there would be no rewards since this is not a money based system. How the deletion is done is yet to be explored, but basically all nodes would agree all blocks older than x months be deleted from their systems.

Would an attacker be able to compute a longer chain if they know of the point at which data is deleted, then show this to the network and then make the network believe this is the correct and valid chain? If so, how can we stop this? (Assume the attacker has less than 51% computing power.) I have looked into timestamps, and time capsule based encryption, but what I want is a mechanism where an attacker cannot successfully create a block without some information that would only be revealed on a specific day.


texts: Server cannot connect to Peers With Some Internet Connections

texts:
I use the internet at my work, at my house, and at various other places. The server can connect with other peers and get block data at all of these locations except for my home. What could be the reason for this? I also can't push to GitHub using SSH whenever I am at home, so I'm guessing these problems are related.

I have tried turning firewalls off, and resetting the router. I still always get the "No block source available error".

I know this is similar to the question asked here, but I think it is different because this question asks why it would be happening only on a particular internet connection.


texts: How to hash data from 'getblocktemplate' request

texts:
I've been reading lots of articles, trying to understand how to hash the data returned from getwork; but I totally overlooked getblocktemplate.

I'm just trying to understand how all the data below is put together to generate hashes, in order to form a valid block (using various nonces).

Apologies if this has been answered already. I know there are lots of articles on how to put together a block header, and using midstate, etc. Most of that I understand; but the data composition of getblocktemplate is quite a bit different, and really threw me off.

If someone would be kind enough to explain the whole hashing process (from a mining point of view), I'd really appreciate it. A programmatic explanation would be ideal, as I'm trying to make my own mining client.

{
    "result":{
        "version":2,
        "previousblockhash":"00000000000000075f2f454573766ffae69fe41d6c7ccfcabbf8588fcd80ed52",
        "transactions":[
                  {
                        "data":"0100000001cba672d0bfdbcc441d171ef0723a191bf050932c6f8adc8a05b0cac2d1eb022f010000006c493046022100a23472410d8fd7eabf5c739bdbee5b6151ff31e10d5cb2b52abeebd5e9c06977022100c2cdde5c632eaaa1029dff2640158aaf9aab73fa021ed4a48b52b33ba416351801210212ee0e9c79a72d88db7af3fed18ae2b7ca48eaed995d9293ae0f94967a70cdf6ffffffff02905f0100000000001976a91482db4e03886ee1225fefaac3ee4f6738eb50df9188ac00f8a093000000001976a914c94f5142dd7e35f5645735788d0fe1343baf146288ac00000000",
                        "hash":"7c90a5087ac4d5b9361d47655812c89b4ad0dee6ecd5e08814d00ce7385aa317",
                        "depends":[],
                        "fee":10000,
                        "sigops":2
                  },
                  ...
            ],
        "coinbaseaux":{
            "flags":"062f503253482f"
        },
        "coinbasevalue":2501100000,
        "target":"0000000000000026222200000000000000000000000000000000000000000000",
        "mintime":1379549850,
        "mutable":[
            "time",
            "transactions",
            "prevblock"
        ],
        "noncerange":"00000000ffffffff",
        "sigoplimit":20000,
        "sizelimit":1000000,
        "curtime":1379553872,
        "bits":"19262222",
        "height":258736
    },
    "error":null,
    "id":"curltest"
}


texts:
How can I use the jsonRPC for the bitcoin client to export the chain into mysql and then sync the two as transactions come in? I'm writing a blockchain explorer for a new alt coin and unfortunately ABE won't work for this particular coin. I can query the chain using jsonRPC just fine for each transaction but I want to be able to store the chain in mySQL for speed and efficiency later on.

Preferred technologies: php & mysql.


texts: How can I convert a bitcoin private key (hex) into a Bitcoin public key?

texts:
How can I take a bitcoin private key encoded in hex:

d1d9a2e9fd3da7e7710310ea17a9edff9e08845c7a6f2ea3d650ba4ae7ee0d3b

and convert it to the corresponding public key:

0478a2a9be183f26e2745c9254957e3b714e8bf161f8bf992f9c628fbddc634e149f52aab6a45cd93187593e2413baf14378e7b2c14c0429f98cbe90c723e1e179

I am NOT looking for a program/tool that does this, but how to do this mathematically. If you can't find that out, you can also give a solution in python 3, which I can understand and convert to something mathematical


texts: Security risk(s) in running bitcoin core full node

texts:
What are the security risks posed by running a full node bitcoin core client? On a typical system, port 8333 is open and all other nodes can actually 'see' my machine and sites like https://bitnodes.earn.com/ can verify the connection.

How can the risks be mitigated? (I'm on Windows)


texts:
Currently there are only 100 billion ripples (XRP), which are slowly being distributed, and a fraction of a ripple is destroyed with each transaction.

In the future if we run out of ripples, or if the developers decide that they need to have more ripples for some reason (to pay their bills?), then would it be possible to create more? If yes, what is the exact process of doing this? Does it require consensus? Or is it just an edit-compile-deploy?


texts: Best way for anonymous purchases (for small amounts only) with credit card or Paypal if you have Bitcoins to spend? Bitcoin-OTC? No name credit card?

texts:
Obviously if you are American or you live somewhere where you have the opportunity to just buy a Visa (or Mastercard) gift card in a store for cash: you can't go better than that. But I don't have that opportunity around my country.

So how would you pay someone (not a big amount) with credit card or Paypal if these are the only payments accepted by the merchant and you simply want to stay anonymous?

If I understand correctly, the hefty fees are if you want to exchange credit card or Paypal to bitcoin because they are reversible payments but for the other way around (bitcoin to credit card or Paypal) there shouldn't be extra fees, correct?

Is Bitcoin-OTC the place to go? What are best practices for this procedure? Is there a newbie-friendly non-techie guide to Bitcoin-OTC?

Is there such a thing as a truly legitimate no-name reloadable Visa/Mastercard or only the once-loadable gift cards are available?


texts: where is index value or hexa value of bitcoin in source code?

texts:
Registered coin types
These are the default registered coin types for usage in level 2 of BIP44 described in chapter "Coin type" above.
All these constants are used as hardened derivation.
index   hexa    coin
0   0x80000000  Bitcoin
1   0x80000001  Bitcoin Testnet

where we can find index, hexa of bitcoin for BIP44 ? how to calculate it ?


texts: What is "version" used for in Bitcoin transactions? Does it have any meaning?

texts:
Some bitcoin transaction have version 2. For example, this transaction

https://blockchain.info/tx/b7022124bc7f31af9342d2f7af98ad9f60f2fd4fa544bf1affca8a436aadda41

if you request a hex (by adding ?format=hex for example) and putting it into https://blockchain.info/decode-tx , you get "version":2.

What does this mean? There are more transactions with version 2 out in the wild, but not that many.

In zcash transactions, version 2 means that the transaction has joinsplits. But I cannot find what it means in bitcoin.

I have found examples of version 2 transactions here and here


texts: How can I tell whether transactions were (not) made via BitPay / Coinbase?

texts:
Background

Recently, Rep. Steve Stockman posed for a photo op with his Bitcoin address on a big QR code, which got shared. He has a Bitcoin donation page which asks for identifying info and goes through BitPay, but of course anyone could send him Bitcoin anonymously, without using that page, if they know the address to send it to.

The Libertarian Party and CoinPAC have Bitcoin donation pages that don't outright list their addresses, but block chain analysis of a donation would probably reveal their main address(es), and those addresses might have received contributions that didn't go through the donation pages. (The LP's page doesn't even require giving your info for it to show you the donation address.)

Stockman & LP's donation pages use BitPay; CoinPAC's uses Bitcoin Builder (which in turn uses Coinbase).

The Livingston County Libertarian Party (addr) and Jim Fulner (addr) publish their Bitcoin addresses openly on their websites, and the Bitcoin Voters PAC published a list of their Bitcoin addresses in their official FEC registration filing‡. None of them even have Bitcoin donation pages that collect info, so of course anything sent to them presumably wasn't properly attributed.

Problem

The FEC requires PACs to know the identity of all contributors (especially for "in-kind" contributions, i.e. anything other than fiat currency). If any of the above received any Bitcoin contributions that didn't get attributed to a specific person (e.g. by going through a donation page that requires disclosing your ID before telling you the address to donate to), that'd probably be an unlawful unidentified in-kind contribution.

For our upcoming FEC advisory opinion request about how to handle Bitcoin, I'd like to have example(s) of how:

it's not possible to "refuse" a Bitcoin transaction (e.g. someone contributing to the above outside of their donation pages)
it's not possible to reliably refund a Bitcoin to the control of the person who sent it (e.g. a transaction that was laundered or came from an exchange)
some transactions are worth less than they cost to get rid of (e.g. dust or complex / intentionally large-byte-size transactions)

Our request proposes a framework for how to deal with these problems (e.g. one could donate unattributed Bitcoin contributions to a charity). I just want real-life examples I can point to that show it's not a purely theoretical issue.

Question

How can I show that Stockman, the Libertarian Party, and/or CoinPAC have received BTC contributions that did not come via their donation pages (and thus BitPay or Coinbase)?

Pointing to specific transactions they received and explaining how it is clear to a third party that those transaction(s) weren't made via BitPay/Coinbase would be extremely helpful.

Other examples of political committees that have published a Bitcoin address or are currently receiving Bitcoins in some way would also be much appreciated.

Thanks in advance!

More info

† See our bitcoin AOR page & my G+ post for some more background.

For the record, we are strictly non-partisan. Our intent here is not to make any particular candidate or party look bad, but rather support transparency in campaign finance.

We want to accept Bitcoin  (potential donors have requested it and we think it's a good idea), but we think it needs to be done carefully to be compatible with current law and good public policy.

Comments on our AOR are welcome, but not really on topic here; I'm just pointing to it for context. The question here is simply: how can I identify a transaction as being / not being made via BitPay or Coinbase, just looking at the block chain? (Let's assume there's no subpoena involved. :-P)

‡ So you needn't transcribe:

18kKJ15uz1nuMJ2kacuahLKLL9NwnsbRQi
1EsR4cdbgPvnD3Gk6wNkTotdzexiN56wXt
14jc8MtHxE6M6Xn7LarvZnXF6GgaaRy1PY
12QeAyDyXiMVn5uwpQUHwS8g2Z3SZf2Kvx
1GuHY98Bxf4mFw2CQEUXqwDUTRqnTRrCt8
113pdko8qQYsvkbV4r7H247oFPFNMnUYqY
1M9AfWnRFmgQgAuTsQssL523ANsxKzfygs
199JdcXMQ41eA9ZPTLUktR9kfAiQRhaErW
1AZxfdTXg5V3gRZMtMfQZrwgBeaQMAtKqN
1NyuGppGprR6uM2koN7hH8wGP8bk6wKh15


texts: Will SegWit allow for m of n multisig with very large n and m?

texts:
By reading this answer, I understand that in m-of-n multisig addresses, m and n are limited by the maximum size allowed by the P2SH redeemScript (i.e. 520 bytes).

However, in this section of BIP141, it is stated that the witnessScript can be as long as 10,000 bytes. As far as I understand, this implies that with SegWit adoption it should be possible to create and use m-of-n multisig addresses with very large m and n that will be considered valid.

By my calculations we will be able to have ns as big as around 300. Am I understanding this correctly?

For instance, would the following witnessScript, which should represent a 50 out of 100 multisig address, be considered valid and spendable under SegWit?

0x01 0x32 <100 public keys> 0x01 0x64 OP_CHECKMULTISIG


texts: How do I send my coins from my Verge paper wallet?

texts: I have created a paper wallet and send some coins from my account on binance.com to it ... How can I send them back to binance from the wallet?


texts: which private key to export from electrum?

texts:
I have an electrum 2FA wallet.

When I list my addresses I get a list of around 30 addresses. (commnand below)

electrum -w /path/to/my/wallet/file/default1 listaddresses

Then I use the below command to obtain private keys from a particular address:

electrum getprivatekeys -w /path/to/my/wallet/file/default1 "myaddress"

Which private key is the one that I should get, so that I can import it to bitcoin-qt wallet? Is this even the right approach?

I tried first two of mentioned 27 addresses but none of them worked.

UPDATE:

Also when I export my master private key from electrum:

electrum getmasterprivate -w /home/path/to/my/wallet

However, I get Invalid private key encoding (code -5) error from bitcoin-qt when trying to import my master private key.( into bitcoin gold core wallet)

UPDATE 2:

I tried to get private keys from all (27)addresses and then run this command to import them all:

importprivkey  L3285rshf9LgkMfaNogEARoJpGhGVMMKd1dQgRgrtGd7EQ8F4qW '' false
importprivkey  L3285rshf9LgkMfaNogEARoJpGhGVMMKd1dQgRgrtGd7EQ8F4qW '' false
importprivkey  L3285rshf9LgkMfaNogEARoJpGhGVMMKd1dQgRgrtGd7EQ8F4qW '' true

output of command was 'null', yet my coins were not imported. Balance is still zero.


texts: Bitcoin core Recent Transactions seems Empty

texts:
I have setup bitcoin core 0.20.1.
Everything is set up correctly, I made a transaction on main net - but it is not showing under recent transactions. Though transaction is confirmed on blockchain.
Also when I am running command getblockinfo, block and header not matched.
Kindly give me a direction in to it.


texts: I've been reading about "loop in" and it seems to be like a one-way offline channel, is that correct?

texts:
Am I oversimplifying? I feel like I must be missing some details.

Can I use my Trezor to sign loop in transactions in theory?


texts: Bitcoin core wallet, uncofirmed transaction

texts:
After 3 days I have this status of my sent transaction:
Status: 0/unconfirmed, in memory pool
Date: 08-Feb-21 18:49
To: bcx 33GnCWPGvzEXKSiRFYtZzgv4WTahiZzE5q
Debit: -0.01274861 BTC
Transaction fee: -0.00000880 BTC
Net amount: -0.01275741 BTC
Transaction ID: d286c58ccb57ff47cdfce40e75457f44a27d0a7e063f6116c0fea4033aaf4ae9
Transaction total size: 223 bytes
Transaction virtual size: 142 bytes
Output index: 0

What can I do?


texts: No computer at the moment, so I have Wallets at two independent websites.  I sent millibits from one wallet to the other.  I hear that you have to use your private key to do that.  So, I guess that site created the private key for me, and they control it?  I certainly don’t know what it is.


texts: Why has UTXO set stopped growing since 2017-06-03?

texts:
The bitcoin UTXO set appears to have stopped growing on 2017-06-3 after 5 or more years of nearly constant increase. What are the reasons (or hypotheses) why?

Charts below:

2012 to 2017-07-11 https://blockchain.info/charts/utxo-count?timespan=all
60 days to 2017-07-11 https://blockchain.info/charts/utxo-count?timespan=all


texts:
I for example own 10 BTC does that mean, in some Blocks in the valid part of the blockchain is written, that I received at some point in time a certain amount of BTC? How do I prove that the Transactions in this block belong to me (without loosing ownership).

How hard is it to find all transactions in a chain which belong to me. Some how this should be possible in $\mathcal{O}(l\cdot m\cdot log(n))$ because of the merkle tree in each block for m blocks and l transactions representing my complete ownership (3 BTC + 4 BTC + 3 BTC = 10 BTC)

Could everybody check my amount of bitcoin if he knows my alias or whatever is used to mark my transactions as mine.

Could I just spend someone elses coins?

Thank you very much in advance.

PS.:
My Plain written math expression was displayed wrong so I edited as tex code but it still does not work. Anyone who can read tex will still be able to read this formula (probably better than before)
If sb knows how to fix it, plz provide a solution.


texts:
I've had some discussions with my colleagues at CU Boulder and we might be interested in developing an open sourced ASIC for Bitcoin mining. If I was to start a Kickstarter project, then who would support it and for how much?

Edit:

My goal is to answer two questions:

I'm betting this question will answer two specific questions. First, why the ASIC open sourced project failed and second further explain the ASIC miner design process. There is currently a low level of understanding in the Bitcoin community about ASIC mining clients outside that they are orders of magnitude faster than GPUS.


texts: How much data traffic does participating in Bitcoin mining cause?

texts: I have a limited amount of data included in my internet plan. If I exceed that limit I get charged extra. So, before signing up for Bitcoin, I'd like to know whether Bitcoin mining causes a lot of internet traffic. Does it involve a lot of downloading and uploading throughout the day?


texts: Why 256 bit for a cryptocurrency is enough but 1024 bit for ssh is not?

texts:
If 256-bit private key is secure enough for Bitcoin and Ethereum then why people are moving from 1024 to 2048-bit RSA for day-to-day cryptographic operations (such as ssh) and even this can be not enough in a several decades?

Is checking that an ECDSA private key corresponds to a public address getting that(!) more time than checking that a RSA private key corresponds to a public key? It should be at least 2^768 times slower.

Or ECDSA gives that much less collisions?

Or there are some other reasons?


texts: BIP0016 pay-to-scripthash transaction validation

texts:
BIP0016 says "Validation fails if there are any operations other than "push data" operations in the scriptSig".

What does it mean "push data operations"? OP_CHECKMULTISIG seems to be allowed but does not look like "push data" to me.


texts: Do I need the bitcoin client running in order to receive bitcoin?

texts:
I am new to this and don't have any bitcoin yet, but I was wondering if I were ever to get any, will I have to have the client running in order to receive them?

Also what would happen if the client it not running at the time a bitcoin is sent to the address?


texts: How to unstuck a low-fee transaction with blockchain.info?

texts:
I've sent a transaction from blockchain.info, but accidentally included too little fee. What can I do to cancel the transaction or speed up the transaction's confirmation?

This is a complementary question to Why is my transaction not getting confirmed and what can I do about it? which answers the question's broader implications and proposes mitigation mostly focused on Bitcoin Core.


texts: Why the system does not try to optimize and put maximum number of transactions in blocks?

texts:
If the reward to add a block is the same, why the system does not try to optimize and put maximum number of transactions in it? I saw an example block where there was only one transaction in it.

Since we are getting one block roughly every 10 minutes, is this a major concern for the efficiency of the system?


texts: Why can't default minimum fee rate be changed to 0.1-0.2 sat/vByte?

texts:
Main question (focus on this incase you are looking to close it as "needs focus"): Why can't we change default minimum fee rate to something below 1 sat/vByte?

It was done in past: https://github.com/bitcoin/bitcoin/pull/3305 why not again?

Why does nobody respond to comments in this pull request? https://github.com/bitcoin/bitcoin/pull/13990 Do I need to be from some OG devs group or from blockstream or chaincode labs to contribute and discuss? Or some PRs are intentionally kept pending because a certain group doesn't want things mentioned in it?

Do you think it will result in spamming? I don't think so and few other people as well: https://www.reddit.com/r/Bitcoin/comments/kjrbny/should_default_minimum_fee_rate_be_01_satvbyte_now/ggyym67


texts: How to update and older version of electrum on ubuntu 17?

texts:
I used the following commands to install electrum:

sudo apt-get install python3-setuptools python3-pyqt5 python3-pip
sudo pip3 install https://download.electrum.org/3.0.5/Electrum-3.0.5.tar.gz

For latest tar files: https://electrum.org/#download

In the future, how would I go about updating electrum? What command would I use to update?

Also, where are the electrum files installed that contains my private keys and wallet?


texts: getblocktemplate times out after being called many times

texts:
I am writing a program about bitcoin mining. It calls the RPC method getblocktemplate every second. Sometimes bitcoind doesn't reply to my RPC getblocktemplate request, but bitcoind still accepted new transactions and downloaded new blocks, but RPC calls didn't work.

I checked the CPU and memory usage; both are fine. I am sure it is not the problem of my computer system, because I tried connecting to some other bitcoind. At first, they worked fine, but after running a long time, this problem would come again.

I did not find a good way to solve it. When the RPC request does not reply, I've tried restarting bitcoind, and then it worked again. My bitcoind version is 0.9.3. Any ideas?


texts: Can an attacker flood the Bitcoin network with fake transactions?

texts:
We are in 2050. People show an ever-growing distrust in the global banking system and start transitioning to only using Bitcoin: most companies accept it as a form of payment, and people settle their bills with Bitcoin. Even the kid with the lemonade stand down the road accepts Bitcoin as her payment.
Banks are worried because they are losing customers and revenue. Legislation has not managed to protect banks and the smaller ones have already started to shut down or provide alternative services.
Then, the CEOs of Atlantis Bank and River Banks, who are the only healthy banks remaining come up with a plan:
A transaction's hash can easily be checked. Why not attack the Bitcoin network with an insurmountable number of fake transactions! We will produce so much noise, and the network nodes will be occupied with checking our fake transactions instead of the real ones, so much so, that a considerable fraction of the total network computing power will be devoted to checking fake hashes. Real transaction verification will come to a halt, and people won't be able to do any everyday trade. They will only be left with one option: return back to us.
Here is my thinking:

Bitcoin's blockchain is increasing in size.
More nodes are added to the Bitcoin network.
Nodes are getting faster.

I expect this to have an overall quadratic effect (in the best-case scenario) in this attack: it will be cheaper for the attacker to generate and submit fake transactions, but it will also be cheaper for the network to reject the fake transactions. BUT the blockchain is increasing in size so at some point the network will be at disadvantage.
Here are some back-of-the-envelope calculations I made, assuming a constant blockchain size of 15 GB:

SHA256 efficiency with today's processors: 45 cycles/byte;
So a chain of size 350 GB, requires 1.6e+13 cycles to be rejected as fake.
With 1 core syncing at 3.5 GHz, this will take 4500 s (1.25 hr).

Are my premises wrong? Won't there be a turning point, when the cost of the largest banks losing customers will be greater than the cost of them launching such an attack (in full secrecy)? How can the network defend itself against these attacks? Sure, one can always add more nodes to the network increasing the fee, but won't that also turn customers back to the banks (i.e. rendering the attack successful)?


texts:
Is it possible to include a file's checksum in a transaction?

Not necessarily in Bitcoin's current blockchain due to the now limited OP_RETURN feature, but just in the blockchain/transaction concept in general.


texts: How to find out the requirements for spending an output script?

texts:
How do you find out the requirements to spend an output script?

Do you decode the hash?


texts: Is who is richer game possible with bitcoin script?

texts:
With Bitcoin script, is it possible to construct a timelocked address X in such a way that:

Players A and B (maybe more players) can send bitcoin to this address;
When the timelock expires,the player that had sent more bitcoin to address X can withdraw all bitcoin to himself;
If deposits where equal, then whoever is first - withdraws;
?


texts:
I mine for fun. Please no responses saying "You really shouldn't mine on that computer. At all. Forget mining exists."

Whenever I try to mine using the instructions given in the README of the GUIMiner, it gives me an error as soon as the bitcoin.exe launches as a server.

Here's the error:

Invalid -rpcallowip subnet specification: *. Valid are a single IP (e.g. 1.2.3.4), a network/netmask (e.g. 1.2.3.4/255.255.255.0) or a network/CIDR (e.g. 1.2.3.4/24).


texts:
I know this community is for bitcoin but I couldn't find any community to talk about crypto-currencies in general so I thought this may be the right place to ask.

I am interested on investing money on Ardor but I am kind of new in the world of crypto-currencies. So if someone could explain me how to buy and then sell Ardor in an easy way and avoiding places that could end up like mt.gox that would be nice.


texts:
I have seen different trading websites on Bitcoin and a question came to my mind:

Security
Why do they require so much identity verification? If I remember correctly MtGox (despite what later happened) when it started, it didn't require any id\bank verification. So my question here is: is identity verification required by law even when dealing with bitcoin trading or is it an anti-fraud system enacted by the trading operator?


texts:
I did a web search before posting, but none of the similar topics shed any light on my problem.

This is the command I'm using to start bitcoind:

./bin/32/bitcoind -datadir=/somedir -daemon

This is the contents of my bitcoin.conf, which is located in /somedir (of course):

server=1
rpcuser=some_user
rpcpassword=some_password
rpcport=8332
rpctimeout=60

Here are the results of netstat --ip -lpan | grep bitcoin

tcp        0      0 127.0.0.1:8332          0.0.0.0:*               LISTEN      24203/bitcoind
tcp        0      0 0.0.0.0:8333            0.0.0.0:*               LISTEN      24203/bitcoind

Then I attempt to send a commend to the bitcoind using:

./bin/32/bitcoind -datadir=/somedir getinfo

Result

error: couldn't connect to server

I'm probably missing something simple and obvious, but what?


texts:
I have read numerous how-to and tutorials (most of them outdated) on how to simply start mining on a pool and I wasn't be able to do it.

Could someone simply describe/enumerate how can someone start pool-mining in a Linux OS (on any distribution) command-line (shell) ?


texts: Is it possible to verify or audit an exchange to determine how much bitcoin they have on deposit?

texts:
Is it possible to verify or audit an exchange (for eg. mnt gox) to determine how much bitcoin they have on deposit?

For example, they could publish one or more bitcoin wallet addresses and by examining the block chain the total amount of bitcoin held could be verified.


texts: blockchain.info api (Balance Updates [POST]) confirmations not received

texts:
I'm trying to use "Balance Updates [POST] Monitor addresses for received and spent payments" from https://blockchain.info/api/api_receive

I subscribe to an address and get the response:

{
  "id": 15108,
  "addr": "1P9RQEr2XeE3PEb44ZE35sfZRRW1JHU8qx",
  "op": "ALL",
  "confs": 3,
  "callback": "https://d83bb66d.ngrok.io/bitcoin/confirmations",
  "onNotification": "DELETE"
}

then with each new transaction I get a notification with 0 confirmations, that looks like this:

{
   "address" : "1P9RQEr2XeE3PEb44ZE35sfZRRW1JHU8qx",
   "confirmations" : 0,
   "transaction_hash" : "38dbb8083a8c3006eae6c1194789941943cb60201ebfb03963188d4eb1d01d23",
   "value" : -9030800
 }

but I never get a notification with the 3rd confirmation

  confs - Optional (Default 3). The number of confirmations the transaction needs to have before a notification is sent.

I tried setting confs to 1, 2 and leaving it as default, but I never get any confirmations, I have tried with different addresses, right now the transaction in this message has 5 confirmations but I didn't get any notification.

https://btc.com/38dbb8083a8c3006eae6c1194789941943cb60201ebfb03963188d4eb1d01d23

does any one know what's wrong ?

thanks


texts: How to compress transaction fee as much as possible?

texts:
I would like to simulate through "offchain" transactions micro payment. To do so, user will need at the beginning to depose some amount as a "credit".
My goal is to compress transaction fee as much as possible and the only constraint is a "big" transaction per month to deduce user credit accordingly to their actions.

My thought was to use only one bitcoin private key per month to reduce from n utxo to one in order to compress size from the "input side".
To differentiate user deposit, I was wondering about providing a specific token to user and "asking him" to store it into the OP_RETURN field of his transaction.

It is worth to try or should I use HD wallet as recommanded even if it will increase the "input size" inevitably ?


texts: Bitcoin Core says it's synced but Blocks folder goes to only 985

texts: I just downloaded and synced bitcoin core v0.14.2 (64-bit).  After several days, it is now synced and (the check mark icon) says "up to date processed 483001 blocks of transaction history"  but when I view the blocks in my Bitcoin/blocks directory, it only goes up to block 00985 (rev00985.dat). Are the other blocks somewhere else?


texts: What Off-Chain programming languages are important in Blockchain development

texts:
I am looking at getting into Blockchain development, and I would like to have some idea about general programming languages that are relatively important compared to the general developer-market.

Myself, I know C++ and C# well, but it would be interesting to combine getting into Blockchain with getting into Python or Functional language or similar.  (Possibly GO or stable parts of JavaScript stacks, probably not Java)

Are some on-chain languages related to particular off-chain languages?


texts: Power Off Dash Miners for Short Time on P2Pool

texts:
I've been DASH ASIC mining (3 miners) for about 1.5 months. I have accounts with the NiceHash and SuprNova pools. I switched to the P2Pool (peer-to-peer pool) method just this evening.

I have typically powered my miners off for about 2-3 minutes per night to make recordings for another activity of mine. I am assuming that as long as I leave my P2Pool program running and simply power my miners off for a short time, I should be fine.

This got me thinking about other needs for the future. When I eventually reconfigure my setup, update my server, update it's OS, or move my mining to a new location, I am guessing that if I setup my P2Pool programs and config file the same way, and start everything back up, I should be fine.

I just want to confirm that these assumptions are correct. If not, what's the best procedure for when you do need to do the above things?


texts: How to check if node is on TestNet or MainNet via `bitcoin-cli`?

texts:
Is there a way, by using bitcoin-cli using RPC querying, if the node I'm querying is running on MainNet or TestNet?

Thanks


texts: How do I access information on blockexplorer.com or blockchain.info without issuing requests to those websites?

texts:
Suppose I want to

get the balance of an address I don't own, or
see all the transactions recently made

Bitcoin Block Explorer has this information, but I don't want to use it

because of security (they might lie)
because of privacy (they might log queries)
because it introduces an additional point of failure
because it's not terribly quick, being a free service and all

How can I get this information from my bitcoind?


texts: Cannot cross-compile for Windows from Ubuntu 18.04

texts:
I have been at this for ages now and I am unable to cross-compile Bitcoin-Core 0.19.1 on my Ubuntu 18.04 machine (not a VM). I follow these exact instructions:

sudo apt install build-essential libtool autotools-dev automake pkg-config bsdmainutils curl git g++-mingw-w64-x86-64
sudo update-alternatives --config x86_64-w64-mingw32-g++ #successfully changes to posix here
git clone https://github.com/bitcoin/bitcoin.git
cd bitcoin
cd depends
make HOST=x86_64-w64-mingw32
cd ..
./autogen.sh # not required when building from tarball
CONFIG_SITE=$PWD/depends/x86_64-w64-mingw32/share/config.site ./configure --prefix=/
make

everything goes well till the autogen step. The configuration script executes normally but I always get the same output no matter what I do...

Build Options:
  with endomorphism   = no
  with ecmult precomp = yes
  with jni            = no
  with benchmarks     = no
  with coverage       = no
  module ecdh         = no
  module recovery     = yes

  asm                 = x86_64
  bignum              = no
  field               = 64bit
  scalar              = 64bit

  CC                  = gcc
  CFLAGS              = -g -O2 -W -std=c89 -pedantic -Wall -Wextra -Wcast-align -Wnested-externs -Wshadow -Wstrict-prototypes -Wno-unused-function -Wno-long-long -Wno-overlength-strings -fvisibility=hidden -O3
  CPPFLAGS            =
  LDFLAGS             =

Fixing libtool for -rpath problems.

Options used to compile and link:
  with wallet   = yes
  with gui / qt = yes
    with bip70  = no
    with qr     = yes
  with zmq      = yes
  with test     = yes
    with prop   = no
    with fuzz   = no
  with bench    = yes
  with upnp     = yes
  use asm       = yes
  sanitizers    =
  debug enabled = no
  gprof enabled = no
  werror        = no

  target os     = linux
  build os      =

  CC            = /usr/bin/ccache gcc
  CFLAGS        = -g -O2
  CPPFLAGS      =   -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2  -DHAVE_BUILD_INFO -D__STDC_FORMAT_MACROS
  CXX           = /usr/bin/ccache g++ -std=c++14
  CXXFLAGS      =   -fstack-reuse=none -Wstack-protector -fstack-protector-all  -Wall -Wextra -Wformat -Wvla -Wswitch -Wformat-security -Wredundant-decls  -Wno-unused-parameter -Wno-implicit-fallthrough   -g -O2
  LDFLAGS       = -pthread  -Wl,-z,relro -Wl,-z,now -pie
  ARFLAGS       = cr

I have tried to uninstall and install the Ubuntu. Also tried to compile on a clean repository several times but the output always shows that the target OS is Linux. I run the make command after this but never get the exe. I am stuck and don't know what else to try. Any help would be appreciated.


texts: How does Nextcoin convert 256-bit Curve25519 public keys into ~20 arabic numerals?

texts:
Nextcoin seems to convert 256-bit Curve25519 256-bit public keys into "account numbers" that have only arabic numbers and seem to only have a length of 20.

How is that done?

Examples

In the Nextcoin forum, users leave their account numbers.


texts: Which one is more effective for attacking the system, controlling 51% of the mining power or 51% of the full nodes?

texts:
I used to think it is the miner who verify the transaction, but it turns out this is really a joint work by the miner and the full nodes; the miner broadcasts the newly discovered block, which contains transactions to the network of full nodes, but it is up to the full node to decide whether to accept them.

Then my question is, even if someone controls the majority of the hash rate, if he does not compromise majority of the full node, can the network simply reject to include the blocks that he broadcasts?


texts:
I bought BTC a few years ago and stored them in cold storage. I encrypted it and saved it in google drive.

Some time ago I decided to check on it. But I couldn't open Bitcoin Armory at all, so in the end I downloaded it via terminal (with cask and homebrew). And that worked!

I opened it, saw I had money but for some reason I couldn't send it. Whenever I would press send button, nothing happened.

So, I reinstalled it a few times and still nothing.

So, I decided a few days ago to delete entire blockchain, remove Bitcoin Core and Armory and remove all files from application support and start over.

Now, I finally downloaded the blockchain with pruning and Armory is stuck on organizing blockchain for a few days now.

So, today I decided to export the keys into Electrum but Electrum says there no Bitcoins inside of it...

I am worried that in the process I didn't accidentally lose them.

My question is, should it take this long?
And what can I do to speed it up, to get to the funds faster?


texts: Coinbase has the address of a bitcoin stored on a blockchain account. How do I access it?

texts:
I don't have the login to the Blockchain account that I stored the bitcoin on. I do have proof of the purchase and transaction of the coin and the coins address, as it is stored on Blockchain. How can I retrieve the coin from Blockchain back into my wallet on Coinbase ?
Thanks.


texts: The standard response is "no, the reward is at least one transaction." What about after there is no more reward?


texts: libwallycore error installing LND on Ubuntu 18.04

texts:
I'm setting up an LND node on Ubuntu 18.04. I've installed python3, and cloned the repo. I ran configure, and get this error on the make command:

checking byteswap.h, usability... no
checking byteswap.h, presence... no
checking for byteswap.h,... no
checking sys/mman.h usability... yes
checking sys/mman.h presence... yes
checking for sys/mman.h... yes
checking whether cc is Clang... no
checking whether pthreads work with -pthread... yes
checking for joinable pthread attribute... PTHREAD_CREATE_JOINABLE
checking whether more special flags are required for pthreads... no
checking for PTHREAD_PRIO_INHERIT... yes
checking asm/page.h usability... no
checking asm/page.h presence... no
checking for asm/page.h... no
checking for python... no
configure: error: Cannot find python in your system path
external/Makefile:51: recipe for target 'external/libwally-core/src/libwallycore.la' failed
make: *** [external/libwally-core/src/libwallycore.la] Error 1

I've searched online but I couldn't find anything helpful to get past this. How can I solve this and get LND installed on Ubuntu 18.04?


texts: Estate planning: how can I ensure my bitcoins are inheritable?

texts:
What are good ways to ensure my bitcoins can be inherited by my family
when I die or become permanently incapacitated?

I think there are probably two significantly different situations to
account for, each with different requirements:

Hot wallet inheritability

I want my family to be able to inherit the bitcoins from my hot wallet,
but I'm not worried about them stealing those bitcoins or monitoring my
public transaction history while I'm still living.

Cold wallet inheritability

I also want my family to be able to inherit the bitcoins from my cold
wallet, but I'd prefer a solution that prevents them from being able to
spend the bitcoins while I'm still alive. If possible, I'd also like to
prevent them from determining my balance while I'm still alive.

It is acceptable for the solution to require periodic activity from
me, such as moving my bitcoins every six months. For example, your
answer may assume that
OP_CHECKLOCKTIMEVERIFY
has become consensus-enforced, as that's likely to happen within the
next few months---and I hope to live that long.
Because I tend to use strong encryption when available, assume that
all my data will be lost at my death unless I've specifically backed
it up for other people to use.

I use Bitcoin Core for both my hot and cold wallets (with separate wallet files), but solutions for other Bitcoin software are welcome.


texts: What happens when the last added block in a blockchain is corrupted? Is it still possible for the block to be accepted by a majority of the miners?


texts: Change in hash rate fraction of mining pools

texts: There are pages that show how the cumulative hash rate of network changes over time however, I wasn't able to find any that shows how hash rate fraction of pools change over time. Is there a page that traces this metric?


texts: Has any illegal data been saved in the Block Chain?

texts: Has any illegal data been saved in the Block Chain, such as an illegal number, or illegal prime?


texts:
I have tried to installed zcoin insight ui & api in my local machine (ubuntu OS) and it is completed all the steps but I m facing issue while start services in frontground.

Let me share with you command, config file.

sudo apt-get install software-properties-common
sudo add-apt-repository ppa:bitcoin/bitcoin
sudo apt-get update
sudo apt-get install libdb4.8-dev libdb4.8++-dev
sudo apt-get install build-essential libtool autotools-dev automake pkg-config libssl-dev libevent-dev bsdmainutils
sudo apt-get install libboost-all-dev
sudo apt install libminiupnpc-dev
sudo apt-get install libzmq3-dev
sudo apt-get install libqrencode-dev
git clone https://github.com/zcoinofficial/zcoin.git
cd zcoin
./autogen.sh
./configure
make
cd src
./zcoind

But getting below error in my terminal:

   [2018-02-07T14:05:58.941Z] info: Starting bitcoin process
zcoind: zmq/zmqpublishnotifier.cpp:99: virtual void CZMQAbstractPublishNotifier::Shutdown(): Assertion `psocket' failed.
[2018-02-07T14:05:59.837Z] warn: Bitcoin process unexpectedly exited with code: null
[2018-02-07T14:05:59.837Z] warn: Restarting bitcoin child process in 5000ms
[2018-02-07T14:06:04.837Z] info: Using bitcoin config file: /home/zcoincore/bitcore-node-zcoin/zcoinnode/data/zcoin.conf
[2018-02-07T14:06:04.838Z] info: Starting bitcoin process
[2018-02-07T14:06:04.847Z] error: Failed to start services

MY Config File  (zcash-bitcore-node.json)

    {
  "network": "testnet",
  "port": 3004,
  "services": [
    "bitcoind",
    "insight-api-zcoin",
    "insight-ui-zcoin",
    "web"
  ],
  "servicesConfig": {
    "bitcoind": {
      "spawn": {
        "datadir": "./data",
        "exec": "/home/zcoincore/zcoin/src/zcoind"
      }
    }
  }
}

Zcash Config  (zcash.conf)

server=1
whitelist=127.0.0.1
txindex=1
addressindex=1
timestampindex=1
spentindex=1
zmqpubrawtx=tcp://127.0.0.1:28332
zmqpubhashblock=tcp://127.0.0.1:28332
rpcallowip=127.0.0.1
rpcuser=YANNISCOOLUSER
rpcpassword=YANNPASSISCOOL
uacomment=bitcore

Can you please help me with it? What is wrong in which step?


texts: How much does SegWit affect transaction size?

texts: I know that SegWit transactions are bigger than normal transactions. But how much? 10% or 15% or..?


texts:
I've been using bitcoin for over a year now without issues. It's been a while since I fired up a bitcoin client though, at least a couple months.

When I try running a bitcoin client (bitcoin-qt version 0.6.0-oneiric0) today, I get the error message

Error loading wallet.dat: Wallet corrupted

I generally use GPG to encrypt and decrypt wallet.dat, and I only have backups of the encrypted wallet.dat.gpg file. I encrypt and decrypt the file only while bitcoin is not running.

I tried following https://bitcointalk.org/index.php?topic=11331.0 . The tools appeared to work (dbdump.py --wallet doesn't throw any errors and spits out what looks like proper wallet contents), but after fixing my wallet with fixwallet.py I get the same "Wallet corrupted" error from the bitcoin client.

The bitcoin client works fine if I blow away my ~/.bitcoin directory.

I'm using 32-bit Ubuntu 11.10 desktop.

I also tried installing the latest bitcoin Qt client on Windows, but that also reports wallet.dat is corrupted.

I tried using a Linux binary from bitcoin.org, and I get this error message:

************************
EXCEPTION: 22DbRunRecoveryException
DbEnv::open: DB_RUNRECOVERY: Fatal error, run database recovery
bitcoin in Runaway exception

terminate called after throwing an instance of 'DbRunRecoveryException'
  what():  DbEnv::open: DB_RUNRECOVERY: Fatal error, run database recovery
Aborted

This may be related: https://github.com/bitcoin/bitcoin/issues/809

Update Mon, 30 Apr 2012 21:45:00 -0700

I ended up trying a bunch of older versions of the bitcoin client, and version 0.3.24-beta reads the wallet just fine! What the heck!?! Gotta be a bug in bitcoin. Now I just need to figure out a way to safely "upgrade" my wallet so it works with 0.6, I guess.

Update Mon, 30 Apr 2012 22:00:00 -0700

Bitcoin 0.4.1 is able to work with everything in my ~/.bitcoin dir. 0.5.4rc3 and 0.6.0 do not work.

Is there some way to serialize the wallet data as plain text? Man, I hate BerkeleyDB.

Update Wed, 02 May 2012 10:43:19 -0700

Using Bitcoin 0.4.1 with my old wallet (which apparently contains something corrupt), I was able to transfer my balance to a new wallet created from scratch with Bitcoin 0.6.0.


texts: Is there a gui to manage the bitcoind server via a browser?

texts: I installed bitcoind on my centos server and was wondering if there was a gui that can control everything the bitcoind does. Would be nice check balance, send funds, create wallets via the browser.


texts: Send payment and message at the same time

texts:
I am using NBitcoin to write some code.  I want to send some bitcoin to an address AND include a message with it.  The message could say who the payment came from or why it was sent.  According to the demos, a txOut can have a destination or a message but not both.  Both are stored in the ScriptPubKey.

Edit.
Someone suggested I could use two Outputs, one for the payment and one for the message, but that doesn't seem to suggest there is a link between the two.


texts:
What does it mean in the bitcoin.conf file when it states:

  server=1 tells Bitcoin-Qt to accept JSON-RPC commands?

If all one needs to do to solo mine is type setgenerate true in the console, then what is at stake with accepting JSON-RPC commands?  Does this allow other software to interact with Bitcoin-Qt, or something akin to that?  Can someone explain?


texts:
There is something i am not sure to understand on bitcoin private/public keys and addresses.
A new bitcoin user "U" first generates a private key.
He can compute several public keys from this private key.
When he wants to receive bitcoins, the user should generate an address. I do not understand if this address is a public key or if it is 2 different things.
If my "U" user should receive bitcoin from 10 different people, he can generate a single common address for this 10 peoples but they will be able to see "U" balance, and see that he receives 10 transactions.
The solution is to generate 10 different addresses. With this solution, each sender will only see its own transaction and won't see the 9 others. I am wrong ?
So, to shortcut, can we say "U" generates 10 "virtual accounts", linked to its private key ?
If so, i do not understand how "U" can computes its own balance: Is there a way for him to recover all public/address he generates from its private key ? Or should user keep all the addresses he generates in a file ?
Thanks


texts: Howto convert mnemonic->seed->root key->derived addresses with c library (libWally)

texts:
I am trying to use the cryptowallet library LibWally to convert a 12-word mnemonic into a set of derived addresses.  I believe my mistake is not with the library itself, but a process flow/algorithmic one, so even if you don't aren't familiar with the library, you may be able to help.
First I validate and convert the mnemonic to a seed with the following code:
    char *mnemonic = "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about";
    bip39_mnemonic_to_seed((const char *)mnemonic, "",
                          (unsigned char *)bytes_output, HMAC_SHA512_LEN,
                           &size_written)
     wally_hex_from_bytes((unsigned char*)bytes_output, size_written, &hex_output)

This gives me the proper seed value; at least it matches what I see on Ian Coleman's Site.  Next I take the seed value in bytes_input (not the hex coded value) and call:
bip32_key_from_seed( (unsigned char*) bytes_output,
    BIP32_ENTROPY_LEN_128,
    BIP32_VER_MAIN_PRIVATE,
    0,
    &key_structure)

And then retrieve the private key with:
bip32_key_to_base58(&key_structure, BIP32_FLAG_KEY_PRIVATE, &output_privkey);

The value in privKey does not match the Bip32 root key shown in Ian's site, though interestingly enough, it matches on the first 16 characters, before diverging (and winding up 4 chars longer).
Am I missing a step here?  Or doing something else wrong?
Edit: Adding some output data.  Using the phrase given above: my (and IanColeman's) seed is:
5eb00bbddcf069084889a8ab9155568165f5c453ccb85e70811aaed6f6da5fc19a5ac40b389cd370d086206dec8aa6c43daea6690f20ad3d8d48b2d2ce9e38e4
Root Key results:
Mine: xprv9s21ZrQH143K2fH5FXCJ4B1iTN2wJSq1h9z2wTZkytm3YgVRxP621bDZ7yqo4KdNWVNcMEyWBHrjThJ9jXMabog7R1RTWFNdSAz2mhX2VjL
IanColeman: xprv9s21ZrQH143K3GJpoapnV8SFfukcVBSfeCficPSGfubmSFDxo1kuHnLisriDvSnRRuL2Qrg5ggqHKNVpxR86QEC8w35uxmGoggxtQTPvfUu
"


texts: I have an old blockchain wallet and a .txt file of 43 words, but the site wants 12 words?

texts: I have a wallet.aes.json file and a .txt file that contains 43 random words. They were both made within minutes of each other back in early 2014, and my confirmation emails from blockchain are also within minutes of these file timestamps. I also have a wallet ID from blockchain. Blockchain wants a recovery phrase of 12 words, and won't accept my 43 word phrase. I'm not sure what I can do to translate these 43 words into something that will let me into this wallet.


texts: I have dual xeon processors (total 48 cores). I am using cpuminer-easy with nicehash pool on fedora. I have noticed that if i keep my number of threads greater than 10, the h/s falls dramatically. I am using Cryptonight algorithm. For 40 threads, i get 2-3h/s per thread while with 10 threads i get 25 -30h/s per thread. What is wrong here? How can i utilize all cores?


texts: How the bitcoin network solves the double-spending problem by adding all the transactions that happened at the same time into one block

texts:
According to my research, I understand if person A sends 2 BTC to person B and at the same time person A sends the same input to himself before the input is considered as spent. So, now there will be a different route for each transaction while broadcasting (where nodes will check transaction chain to verify the history of ownership by the previous transactions) in the bitcoin network and might be the wrong one got confirmed first. Obviously, the second one will be rejected and the network will give contradiction while consensus. So, according to my understanding bitcoin network solve this issue by adding all the transactions that happened at the same time into one block of the block-chain. Please let me know if I am wrong. I will appreciate your guidance. Thanks
So, My question is: How the bitcoin network solves this issue by adding all the transactions that happened at the same time into one block?


texts: how to explain to a child WHAT is BTC made of which is received as reward for mining a block?

texts:
i looked at different questions in this forum but cannot still clearly figure out. i am not a developer.
ok, we have currently 6,25 bitcoin as reward for miners. how to understand in 1-2 non-technical sentences what do these 6,25 bitcoins (or millions of satoshis) represent? is this just a line of code (just numbers) which was programmed at the beginning?
i understand principle of bitcoin monetary policy, mining main principles, etc... i just do not understand WHAT is this 'coin' exactly... imagine me as child, how would you tell me what do these 6,25 numbers represent itself, what are they made of, are they just numbers we send to each other in transaction? any comparison to any currently mainstream store of values like numbers on banknote, gold ounce, etc...
thanks in advance


texts: Getting bx to create a private key from known chain code and a private EC WIF key?

texts:
I was trying to get strong feedback that I really understood a portion of the Mastering Bitcoin Book concerning HD wallets. The picture below is the reference for the question.

I checked out the functionality exposed by a Javascript Brain Wallet. By entering "123" (is a very poor secret) into a field for a HD brainwallet and the following extended private key emerged: xprv9s21ZrQH143K2hYgcmBxsUfRw3Kbu3eEGXFJrM8Cqtewuqa6Y6nXbB7tv9HnrBajqjptPsRjL9FmnwLa317jHWJ5dpwTc99C2AiPztPRaxk.

Clicking the button to the right of the private key got me to another page indicating the master private chain code is 40675733fc35303c1c75bc598716f24af225528da686192ceb567c88313f8885 and the master private key is L4h3ZSQ3yfFNbovQjTGumvUGEfB1a7oFAhbkhMMFGsdDKoTSwwU8.

Given these last two pieces of information and an index of 0, is it possible to issue a number a number of bx commands and concatenate their output results to feed a HMAC-SHA512 hash to arrive at private WIF key of KwMsDozFYQG7SZFwfvFRwWDhfuMJjkE669WxP6SqrpDPsCBrPV4p public address 15jbcT7wE81s8n2dbEGRFGf65zp7PHrjxh?  If so, how is this accomplished or does bx need to be complemented by some other command that renders HMAC-SHA512 functionality?


texts: Can a competing cryptocurrency make Bitcoin obsolete?

texts:
If a new cryptocurrency is created, with some unknown property that Bitcoin does not have, can Bitcoin be adapted to include this property, or will Bitcoin become obsolete?

(I believe I know the answer, but I still think it's an important question. Spurred by this reddit post)


texts: How to list all addresses in a deterministic wallet?

texts:
Deterministic wallets generate a key space following established standards, using a random passphrase as seed. I have a couple of questions:

How many keys can be generated by a deterministic wallet?
Is it possible to list all keys (public keys, to avoid leaking critical information) in such a wallet?


texts: eth says that I just mined something: now what?

texts:
I'm using eth to GPU mine for Ethereum. After running for 10 minutes, it said:

i  23:58:32|gpuminer0  Mined #7a877124ΓÇª (parent: #d4e56740ΓÇª )

If this were Bitcoin, I'd go check it out on blockchain.info and also rejoice that I just got 25 BTC. What did I accomplish for Ethereum and how do I confirm it?


texts:
A few days earlier, a guy approached me claiming to mine bitcoins and multiplying my bitcoins 10 times.
I invested with $700 and the blockchain wallet after 24 hours showed me $7000 worth bitcoins.
But it was non-spendable.
The guy told me to give him half the commission so that he could approve the profits for them to reflect in my wallet which could be spendable.
I bought $350 worth of BTC and transferred them to The guy’s wallet address. And now he is asking for a transfer fee of $300 worth bitcoins So he can transfer my profits to my bank account.

The profits that reflected in my blockchain wallet are still non-spendable. His approval of the profits did not reflect that money in the wallet. And now he is asking for more money.

Is this a scam?
How can I recover my initial investment?
Where can I report him?


texts: What currency do the antminer pools generate?

texts: Sorry to be a newbie, But I'm pretty lost. I just set up my first Antminer and don't understand very much. There are three pools suggested as the default. What am I generating as far as currency?


texts: Can we look at how long it took to solve for the most recent block in the blockchain? (and how?)

texts: For example, can we see, the latest block, somebody got lucky and solved it in 1 minute, but then the next block, nobody solved it until 18 minutes later? (and how can we see it?)


texts: how to get unspents of an address using bitcoind?

texts:
I am using bitcoind. I have gone through the json-rpc api's.

listunspent [minconf=1] [maxconf=999999]    version 0.7 Returns array of unspent transaction inputs in the wallet.

listunspent method gives an unspent transaction inputs of the addresses in the wallet.

I want to get an unspent transaction inputs of one particular bitcoin address which are currently not part of our wallet. Could anyone tell me how to get that?


texts: How to compile newest source and find merkleRoot hash value?

texts:
I am following youtube video for make own coin.

I did below 4 lines command for compile  newest bitcoin source.

./autogen.sh

./configure

make

sudo make install

And run ./mycoind file at src/

after this, debug folder does not generated debug.log file like video at [Home/.mycoin/] folder.

This is for modify assert(block.hashMerfleRoot == uint256 ..... value.

Why and how to fix?

Thanks.


texts: What are the standard formats of transaction outputs?

texts:
A transaction output can have the type

Pay to public key hash, P2PKH, where the ScriptPubKey field has the format:

76 a9 14 <20-byte hash of pubkey> 88 ac
Pay to script hash, P2SH, used for e.g. multisig:

a9 14 <20-byte hash of script> 87

There is also something called P2WPKH and P2WSH. Can you show me how these outputs are formatted, and are there any more possible output formats than these four?


texts: Trying to import a private key into bitcoind

texts:
I am in a special situation where I need to import my private key credentials and basically restore a wallet to bitcoind. bitcoind is running and I do have an rpc user/pass and server=1 in the bitcoind.conf, but no matter what I do, when I try and import the key I get the following error.
There is no password nor encryption on the wallet.

root@coined:/home#  bitcoind importprivkey "5JxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxHjdCia9dt7" "root"
error: {"code":-4,"message":"Error adding key to wallet"}


texts:
Would it be possible to create energy backed cryptocurrency?

There are some earlier theories of creating energy backed money. However the instant challenges I see are

Energy (as an electricity) is globally not transferable, storeable, and must be consumed immediately. It would only work if buyer and seller are connected to the same grid.
The value of energy varies highly depending on the location. E.g. 1 kWh in Africa is much more worth than 1 kWh in New York. The problem of unified exchange rate, e.g. like with gold, would make it very hard to the medium for exchange of value.

Thus, energy backed money may not work in a sense that "1 kWh = 1 coin", because energy lacks the properties to become a transfer of value? But are there other aspects one could use cryptocurrency to bind it to the value of energy?


texts: OS Windows Reinstalled, Bitcoin Core bitcoins lost, how do I recover them?

texts:
I've lost my bitcoins when I reinstalled OS on my computer.

I still have my receiving address and the password I used to encrypt my Bitcoin Core Wallet.

How do I recover the lost bitcoins? Does anyone know? Thanks!


texts: I've encountered the page on "Bitcoin stick" while browsing the Research wiki page. The information provided on the subject is quite small. Can anyone explain what it really is and where one can find more information on the subject?


texts: I wonder: is the built-in accounts facility scalable enough that you can assign each newly minted address to a different account?  Or am I going to run into hard limits, or a database that becomes too sluggish because accounts were meant to be few in number?


texts: Is it normal that blk and rev files are blank?

texts:
I am trying to run a full node on a Raspberry Pi 3.
My computer is also not so good for initial block download.
So I got a borrowed computer and synced the whole blockchain overnight.
Then I copied "blocks" and "chainstate" folders, and returned the borrowed computer to lender.
I copied the files over to the Raspi USB harddisk, everything was fine, it synced and I could use it normally.
Now I notice that a few "blk####" and "rev####" files are 0kb in size (I am not sure if they were normal before and got somehow corrupted or if they have always been like that, see pictures below).

So my question is: is it normal to have 0kb files like that?


texts: Is there really a limited supply of bitcoin?

texts:
I don't get how there's a limited supply of 21 million bitcoin if we can go into the infinite amount of decimal places.

So for example, you can't go less then 1 cent if we take USD. in BTC, you can have 0.00000001 or however many zeros after the point, not sure but I would assume it's alot. So isn't there alot more than 21 million bitcoins, if we take in decimals into account?


texts: What are the challenges ahead of bitcoin foundation? What are the issues they currently working on? How to track their activities?


texts: What is A matching transaction in the pool validation?

texts:
I'm reading "mastering bitcoin" and got into transaction validation.
Can you explain to me what is the meaning of "A matching transaction in the pool, or in a block in the main branch, must exist." ?


texts: bitcoin node startup daemon with created wallet

texts:
When I restart the Bitcoin node, I would like to load the wallet I created in the "wallets" subdirectory.

bitcoin-cli createwallet "1"
bitcoin-cli listwallets -> result : "", "1"
bitcoin-cli -testnet stop
bitcoind -testnet -daemon
bitcoin-cli listwallets -> result : ""

thanks.


texts: Random generation of elliptic curve points: is there a preferred approach?

texts:
While most practical applications are concerned with the random generation of private keys, anyone who wishes to write unit-testing code on the secp256k1 elliptic curve group may wish to have the ability to randomly generate elliptic curve points.

I can immediately think to two approaches for doing so, one consisting in returning the elliptic point associated with a random secret, the other consisting in randomly generating X, computing X^3 + 7 until we obtain a quadratic residue mod p and compute a square root (which reduces to taking a power (p+1)/4 mod p since p = 3 mod 4). I am suspecting that the latter approach is computationally more efficient as it does not involve the scalar multiplication of the EC group, but only arithmetic operations and exponentiation mod p. Is there a known preferred approach to this question? Assuming my intuition is right, and generating X until X^3 + 7 is a quadratic residue is the way to go, another question naturally arises: what is the preferred approach to test whether a number mod p has a square root? Is it worth implementing the Legendre symbol, or is it better to simply check whether the prospective square root (raising to the power (p+1)/4) fits the bill?

Early optimization is the root of all evil, so maybe I shouldn't be asking this question, especially as the performance of unit testing code probably doesn't matter. But I figure that if some elements of best practice are known regarding bitcoin development, I may as well adopt them and do the right thing.


texts:
I'm reading about SegWit and the BIP 141 in particular and I don't understand what is the motivation behind the P2SH nesting.

At first I thought the P2WPKH is not valid on non-upgraded nodes, so P2WPKH nested in P2SH is a way to make this a soft fork (with the P2WPKH being used only after all nodes are upgraded). But as I was looking into the definition of P2WPKH I came to a conclusion it is a ANYONE_CAN_SPEND transaction on the older nodes.

My another guess was that this might be to enable a segwit-unaware wallet to create a transaction containing a scriptPubKey, which can be redeemed later on using a segwit witness. Is that right? Are there any other benefits? It seems like a little bit too much of a hassle.


texts: How to search (via json API) transactions to my wallet?

texts:
I'm new to bitcoin and want to take payments with it on my website.
Taking payment isn't a problem but the manually process of verifying payments and matching up with users is.
Is there any way to use an API to search the transactions to my address and look for specific text in the "message" field?
Thanks
Matt


texts: How can I generate bitcoin cash addresses programmatically?

texts: If I'm a mobile developer who wants to integrate bitcoin cash in an app, how can I generate Bitcoin Cash addresses programmatically, without relying on a 3rd party service, like Coinbase?


texts: I am running two altcoin clients on different network, connected by VPN. The addnode  command works fine, and nodes connects. But what to do if I want others to connect to my network? The ip addresses i have are local subnet addresses.


texts: Sent some testnet Bitcoin to Bitcoin Core wallet but balance is still zero

texts:
I got the testnet Bitcoin address with this command:

bitcoin-cli -testnet getnewaddress

And here is the Bitcoin address:
2NDtNjDbEiNiKDuAnwyKBmRPQ49NNpesdhE

As you can see in blockchain there was a confirmed transaction.

I checked my balance with this command:

bitcoin-cli -testnet getbalance

but the balance is 0.00000000

What is wrong here and how to fix this problem?


texts:
I have bitcoind and lnd set up on my Raspberry Pi according to the guide here.

Everything works great for the most part, and my node is up and running. I've been able to open a channel with another node, and other nodes have opened channel with me.

However, very often when I try to run a command against lncli the operation fails with the error [lncli] rpc error: code = Unavailable desc = grpc: the connection is unavailable. The lnd logs (sudo journalctl -f -u lnd) show:

lnd.service: Main process exited, code=exited, status=1/FAILURE
lnd.service: Unit entered failed state.
lnd.service: Failed with result 'exit-code'.

At those times, it seems like bitcoin is resyncing blocks (tail -f ./bitcoin/debug.log):

init message: Rewinding blocks...
init message: Verifying blocks...
Verifying last 6 blocks at level 3
[0%]...[16%]...[33%]...[50%]...[66%]...[83%]...[99%]...[DONE].

If I wait for the above to finish and fresh UpdateTips to start rolling in, I'm able to unlock and use lncli again.

What's actually going on here? Do I just have bad luck/timing? Does bitcoind frequently rewind blocks, causing the rpc calls to fail?


texts: When one sets up a transaction, the input of the transaction needs to have a script with a signature to show that you can spend those coins. Which fields of the previous and current transactions need to be concatenated into a message and signed to generate a proper signature? Can someone provide some examples?


texts:
I'm mining Litecoins in the q30.qhor.net P2Pool node at a current rate of around 75 kH/s.

I've been reading that decentralized p2pool mining differs a bit from centralized mining pools, e.g. that you only get paid out when a block is solved successfully.

Now, I'm mining for about 8h now in this p2pool and during that time 3 blocks were solved:

Block   Time                            Luck
409925  Tue, 20 Aug 2013 17:09:16 GMT   155.4%
409848  Tue, 20 Aug 2013 14:02:12 GMT   95.1%
409784  Tue, 20 Aug 2013 12:07:41 GMT   165.1%

That means, some payouts occured during that time. I checked some of the other addresses, they really got instant payouts. But I didn't.

Address                             Hash Rate   Stale   Amount (LTC)
LV6GjHN8...someltcaddress..aWdKZ2g  2.93MH/s    4.36%   0.21685736
LWoKVQ8y...someltcaddress..2dm5FqL  2.44MH/s    5.12%   0.22766967
LedmP6yA...someltcaddress..hGBdLHW  1.97MH/s    7.02%   0.13804534
...
LUj1UAKL...myaddresshere...jWYAPA9  77.8kH/s    1.69%   -

I'm using pool's cpuminer 2.3.2 and see a lot of accepted shares.

 $ ./minerd --version
cpuminer 2.3.2
libcurl/7.31.0 OpenSSL/1.0.1c zlib/1.2.8
 $ ./minerd -a scrypt -r 1 -t 12 -s 6 -o http://q30.qhor.net:9327 -O LUj1UAKL...myaddresshere...jWYAPA9+0.00001800:1
...
[2013-08-20 20:57:05] thread 1: 168 hashes, 6.48 khash/s
[2013-08-20 20:57:05] accepted: 4270/4396 (97.13%), 76.76 khash/s (yay!!!)
[2013-08-20 20:57:05] thread 9: 4116 hashes, 6.41 khash/s
[2013-08-20 20:57:05] accepted: 4271/4397 (97.13%), 76.76 khash/s (yay!!!)
[2013-08-20 20:57:06] thread 2: 7452 hashes, 6.47 khash/s
[2013-08-20 20:57:06] accepted: 4272/4398 (97.14%), 76.76 khash/s (yay!!!)

But I did not get any payout, yet. Why?


texts: what happens if one node goes down in lightning network multihop payments?

texts:
In a scenario where we have the following lightning payment channels:

Alice <-> Bob <-> Carol <-> Dave

Alice wants to pay Dave. Dave generates a payment request by selecting a random R and providing to Alice HASH(R).

This is routed via Bob and Carol, because Alice has no channel with Dave. It is clear that R is passed from one to another, but what happens if one hop goes suddenly down, for example Bob goes down after Carol received R from Dave.


texts: Will there be a hard-fork with BTC and B2X?

texts:
Will there be a hard-fork between B2X and BTC?
How can we know for sure?
When will it occur?

Thank you!

David


texts: Set a standard transaction fee in bitcoind

texts:
Hello I was wondering if it is possible to set a standard transaction fee in bitcoind like 0.0001 BTC.
Because now it uses around 0.000026 BTC per transaction and it takes ages to confirm.

Thanks in advance!


texts: Blockchain transaction goes missing when searched from a few sites

texts:
So I have an unconfirmed transaction since almost a week now.
The transaction ID is fd82fb9711afc48623fa13fa3963121f88160afe56fc968feaf02e5f73e7b764

This is due to the fact that exchange cex.io to save money bunch a huge number of requests in a single transaction which effectively brought down the satoshi/byte.

Today when I searched for the transaction in a few blockchain sites it says transaction Not found. Sites like blockchain.info show the transaction but multiple sites like live.blockcypher.com, blockchair.com, blockexplorer.com etc all show transaction missing.

What does this mean? Is it that my transaction will be dropped finally? I prefer it being dropped as this will never get confirmed. What is the sure way of checking if a transaction is dropped?


texts: What prevents somebody from "re-mining" an already existing Bitcoin?

texts:
This may reveal that I know nothing about math or cryptography.
Let's say that a given Bitcoin was "lost" in that it was once mined and assigned/given to a person who had it in their wallet.dat, but then they either lost the password to this file, or deleted it, or otherwise lost access to it forever (or without any realistic hope of ever retrieving it).
Now, that Bitcoin has been mined out of the 21,000,000 total ones ever, but it's "lost".
But if a computer once guessed the right private key for that coin, why can't another computer do it again?
Basically, isn't it possible that all the Bitcoins that are currently mined and in possession of somebody, could be "re-mined"?
Is it just "extremely unlikely"? And you cannot "target" a specific existing private key/receive address/Bitcoin?
I'm always fearing that one day, somebody "re-mines" the Bitcoins that I have, thus seizing access to them, either by sheer accident or by somehow deducing the ones I own and specifically try to "re-mine" those in order to make me poor?


texts: What is the security and trust model of an Opendime?

texts:
Opendimes use some entropy on the device in combination with some entropy added by the owner to generate private keys directly on the device. Until the device's seal is broken, it is claimed to be impossible to access the private key and only the address can be learned instead.

What are the security assumptions that a user of an Opendime is making and how reasonable is it to trust the device? Are there any special attacks that a payee exposes himself to when accepting payments with an Opendime from either the creator of the device, or a payer?


texts:
Since the blockchain is stored in a distributed database, is it possible that one block can be lost? Then it would be impossible to link future blocks to previous blocks.

How many copies of the blockchain are there?


texts: How to create a valid unsigned transaction

texts:
How can I create a valid unsigned transaction which can be broadcasted and mined using these addresses?

Could someone create the raw transaction and show me?

sender's address: 1NsRUK6vmPbtQa8sSjeXVxeYQiGCGNi6W3

receiver's address: 37KSBUjixDYxmgmTdepb79aso69vPZrLu2

Note: These are both my addresses and their balances are 0.


texts: is it possible to increase fee from command line in electrum? I walked through all electrum commands but can't find such command.


texts:
I started bcoin in daemon mode (s I understand it is the same as full-node) with specifying network: testnet. As I understand it connected to the world-wide testnet. Now I want to get some test BTC. Running bcoin wallet get and getting this response:

{
  "network": "testnet",
  "wid": 1,
  "id": "primary",
  "initialized": true,
  "watchOnly": false,
  "accountDepth": 2,
  ..............
  "account": {
    "name": "default",
    "initialized": true,
    "witness": false,
    "watchOnly": false,
    "type": "pubkeyhash",
    "m": 1,
    "n": 1,
    ............
    "receiveAddress": "mz8iAEUBM6WueVgCzRsTht5wWjfyYxTF9c",
    "nestedAddress": null,
    "changeAddress": "mvSa7AnTQDTyWPBe6EbuB6KT5rLSrSgRP8",
    .............
    "keys": []
  }
}

So, as I see I have default account with wallet address mz8iAEUBM6WueVgCzRsTht5wWjfyYxTF9c. Then I am going to any testnet faucet (for instance https://testnet.manu.backend.hamburg/faucet) and putting this address. After a while I see nothing on my balance: bcoin wallet get

{
  "wid": 1,
  "id": "primary",
  "account": -1,
  "unconfirmed": 0,
  "confirmed": 0
}

My question is: how to acquire testnet BTC for dev purposes?


texts: What actually caps Bitcoin's supply at 21 million?

texts: I have seen everywhere that the total BTC supply is permanently capped at 21 million. I understand blockchain, cryptography, SHA256, etc... generally, but where/what is actually capping the supply at 21 million? Looking this up online usually leads to generic 'its written in the code' and this stack question seems to point to the code, but I do not understand it. Is the supply cap really just some hard code in the original protocol? Is this modifiable?


texts: Cathie Wood "Bitcoin not suitable for ETFs" - why?

texts:
Cathie Wood of ARK Invest is quoted in a Bloomberg article:

Wood was a believer in Bitcoin, too, and it powered some of the early gains in her funds. But after discovering an adverse tax rule, Ark decided it wasn’t appropriate for ETFs. Bitcoin, which hit $20,000 this week for the first time, is a 7% position in certain Ark separate accounts. Wood said she remains “extremely bullish.”

Markup mine.
What is she talking about?


texts: At the beginning. when nobody owned bitcoins. what was being minned?

texts:
what I understood about mining a block is that,
New/pending transactions are to be verified and placed into a block solving the proof of work.
The miners are rewarded for this task.

In the very beginning.. when there were no transactions taking place.. what were they mining? what were in those blocks?
how did bitcoin circulate all over the world?


texts: How to generate wallet address? And how to get that connected with internet for transactions?

texts:
I would like to know how a wallet address can be generated? One site suggested me to create a script for that, that is 1 option, I would like if any other there.

Mainly I am willing to know is how that address will get connected to network for transactions?

If I have my wallet address and I give it to anyone, will the other be able to deposit bitcoins in that address, using my wallet address only? If yes how will the network come to know about my wallet address?


texts:
I might just have had a major screw up.
I created a bitcoin wallet with Electrum (bip32 standard). I then used the xpub key (extended public key) to generate payment addresses in my online store. It looks like my online store plug in uses the bip44 standard. This resulted in different "receiving address" then the ones generated by the Electrum wallet. Unfortunately I didn't notice until I received the first BTC transaction.
I tried to enter the seedwords from my Electrum wallet in the Mycelium wallet which I believe is using the bib44 standard. I got an error message that the checksum of the seed doesn't match.
BTW, the addresses generated by Electrum start with "1", the addresses generated by the webstore with "3".
Am I screwed?


texts:
When looking at transaction details (under summary of recent transactions) on blockchain.info what is Network Propagation, and what does the value greater than 100% mean exactly?

For example Network Propagation 120% - 2168 Nodes - (Excellent)


texts: Hash rate for litecoind is way below the one I get for bitcoind, is this normal?

texts: I'm running bitcoind on an Ubuntu EC2 image in the Amazon cloud; on another identical image I'm running litecoind. I compiled both of these on the bitcoind instance. According to the getmininginfo command, my hashes per second for litecoind ranges around 300, while for bitcoind it is over 300000; 3 orders of magnitude greater. Is this normal, or have I botched something?


texts: How to use the "Bootstrap.dat" file with bitcoin-qt?

texts:
I have searched around, and nothing I find works for me.
Downloaded the approx. 10 GB Bootstrap.dat file. Now stuck on trying to link it with Bitcoin-QT.

Tried the following command in the console box in the bitcoin-qt app:

bitcon-qt -loadblock=/path/to/bootstrap.dat

Also tried copying the file into the AppData/Roaming/Bitcoin file... Still no luck.

I'm running Windows 7, anyone have step by step instructions on how to set this up?


texts: I'm really new to Bitcoin (just started today) so forgive me if this question has been asked before but I can't seem to find an answer on Google. From what I understand, the Bitcoin program is capable of encrypting your wallet for you. So, can I safely encrypt the wallet (using bitcoin-qt) then move it to my Dropbox folder and then symlink it so the program will access the copy in my Dropbox. I don't really want to lose my wallet.