texts: A full/multi nonce range search or just a partial range search?

texts:
In a work, there are only two elements in the block header change between hash attempts. That is, NTime and Nonce. The miner starts the nonce search to get a valid share, and there are several possibilities:

1) In a single nonce range (0~2^32-1), the miner find a nonce which meets the requirement of the valid share, so the miner exits the nonce search for this work and submit the nonce instantly, and then get another work from the pool.

2) In a single nonce range (0~2^32-1), the miner find a nonce which meets the requirement of the valid share, then the miner record it, and go on the nonce search until the complete of the nonce range search, and after this full range search the miner submit the recorded nonces  and get another work from the pool.

3) The miner can't find a valid nonce after a full nonce range attempts, so it performs NTime rolling, and then start a new nonce range search, and also there are also some possibilities just like the above statements for the miner to finish this work and get another work from the pool.

Actually, my question implies another question, for a fixed work(except for the nonce), is it possible that more than one nonce can be found to get a valid diff 1 share?


texts: Is transactions in bitcoin blockchain always coin transaction?

texts: I'm new to crypto currencies correct me if I am wrong, when I checked the block explorer I found a single block contains nearly 2300 transaction in it and I think at an average every 10 minutes a new block is created. My question is, Is all the transaction in the block is, one sending bitcoins to some other or Is there any other application running in bitcoin block chain like in etherium. Because with this much of demand in bitcoin and that many transactions happening even inside 10 minutes is quite unbelievable (sometimes this question might sound stupid).


texts: Bitcoin security, what is wrong with my thinking?

texts:
Lets assume I keep generating random public keys with their matching private keys and never use them.
Severals years later I am checking for positive match against the blockchain for all my generated public keys.
If a match is found that means someone is actually using a public key I generated in the past and for which I know the private key.
I should then be able to gain control over someone else wallet even in the case of a paper or brain wallet.
Best regards,


texts: All Bitcoin Public Keys with non-zero balance

texts:
I want to get a database or otherwise retrieve a set off all bitcoin public keys (not addresses) that have non zero balances.

What would be the easiest way to do that? Is there an API that could do such thing? Do I have to download and prune the whole blockchain? If so how would I do that?


texts: Why is there an addrlocal field in the output of the RPC call getPeerInfo, and how SPVs handle it?

texts:
According to the Bitcoin core developer reference, the RPC call getPeerInfo has in its output a field called "addrlocal" which holds our IP from the worldview of the peer.

Why is this output there? Is it used anywhere? Does it have a use case?

Furthermore, they commented that "Most SPV nodes set this to 127.0.0.1:8333", why would an SPV node do that?


texts: Pegged transfer from private blockchain to sidechains - Issue

texts:
I am trying to do a pegged transfer from one of my private blockchain to a sidechains using sidechain-manipulation.py (https://github.com/ElementsProject/elements/blob/alpha/contrib/sidechain-manipulation.py)

I did a successful address creation and send-to-sidechain after doing necesary modifications on Sidechain chainparams(presently configured only for main and testnet)

While I try to claim in the sidechain I get the following error

Traceback (most recent call last):
  File "./contrib/sidechain-manipulation.py", line 176, in <module>
    txid = sidechain.sendrawtransaction(res_tx)
  File "/usr/local/lib/python2.7/dist-packages/bitcoinrpc/authproxy.py", line 140, in __call__
    raise JSONRPCException(response['error'])
JSONRPCException: -26: 16: mandatory-script-verify-flag-failed (Script failed an OP_CHECKSIGVERIFY operation)

Got the following error from an RPC Call:
{u'message': u'16: mandatory-script-verify-flag-failed (Script failed an OP_CHECKSIGVERIFY operation)', u'code': -26}

I see the following lines in claim-on-sidechains sidechain-manipulation.py,

    # Might need to calculate the scriptSig here
    secondScriptSig = "1"

My question is, what is this secondScriptSig ?!?! How does it relate to withdrawKeys?


texts: Invalid public key was spent! How was this possible?

texts:
From previous questions this bitcoin 1FYMZEHnszCHKTBdFZ2DLrUuk3dGwYKQxh address had an invalid public key of "00" and was unspendable but the coins are now spent?? The invalid key was generated by a bug in the wallet software the owner was using and should have been "locked" due to the invalid key

see link to the owners original query
https://www.reddit.com/r/Bitcoin/comments/2t3vn0/i_cant_send_my_btc_a_triangle_apear_i_use_multibit/

also see link to a paper that lists that this is an invalid key
https://www.microsoft.com/en-us/research/wp-content/uploads/2013/11/734.pdf?from=http%3A%2F%2Fresearch.microsoft.com%2Fpubs%2F204914%2F734.pdf

see page 11


texts: I've read in some places that the next halving event will be on 2016. How can this be estimated?


texts: How to initiate a transaction with address and privateKey using nodejs

texts:
I have a list of bitcoin addresses and private keys, I need to write an automation script which checks for the balance in each address and transfer the balance funds to another bitcoin address. My question is how I perform the fund transfer with address and privateKey using nodejs

Thanks in Advance


texts: How often is a block mined on the bitcoin testnet?

texts: I've been watching testnet for a few minutes and I haven't seen a block come in yet. I'm testing some code that works with incoming validated blocks, and I'd like to test it out.


texts: Equivalent of Etherscant for Bitcoin (econometric analysis)

texts: I am writing the first chapter of my PhD thesis on the crypto market. I'm looking for an historical time series on mining rewards for the Bitcoin. Can you recommend me an open source and reliable data source please?


texts:
Question: is it possible to further obfuscate ownership/origin of bitcoins by trading it for another cryptocurrency at an exchange? (as it is easier to do this for large amounts than it is with cash)

Lets start with 10000 bitcoins. The point here is to make the size a large and conspicuous one.

You have 10000 bitcoin that you would like to obfuscate the origin of. Right now those 10000 bitcoins are at an address you control. The object here is to move around that value between addresses.

Just sending them to another address would have a record of all the addresses they were sent to.

Sending them to an exchange and back would still have the record as well as the exchange's records.

Even breaking it up into smaller transactions just makes it more tedious to follow the pieces but it is all still easily browsable using existing services.

But what if they were traded for another cryptocurrency at an exchange?

This gives you the initial transfer to the exchange, everyone and the exchange can see that. But then they are exchanged, probably nominally, on the exchange for a different crpytocurrency. A completely different blockchain. For someone doing an analysis on the trail of these coins, how would they be able to account for switching blockchains? Would it even be possible at all?

Going to a different blockchain, and even then going back to the bitcoin blockchain at a different address seems like an impossible thing to follow.

Is there a way to follow coins exchanged between blockchains? Is there a way to know that the owner of the 10,000 bitcoins exchanged them? since on the bitcoin blockchain, it will all have happened on the exchange and the coins will simply look like they have been broken up between addresses, but you wouldn't know that the original owner is no longer holding those coins at all.


texts: Bruteforce bitcoin address - I know the words + public address but not the order

texts:
I have a long list of 1million+ permutations of a 12 word BIP39 seed. How can I try them all on a bitcoin address?

edit: I know the address and the 12 words but i don't know the order of the words


texts: How do I build Bitcoin from source in Linux?

texts:
I am running an Ubuntu Virtualbox, how do I build Bitcoin from source and run it in this environment?

I'm using the build notes from the bitcoin core github and I get the following errors when trying to do make -f makefile.unix bitcoind:

net.cpp:48:15: error: 'pnodeLocalHost' was declared 'extern' and later 'static'
net.h:476:15: error: previous declaration of 'pnodeLocalHost'
net.cpp:51:15: error: 'hListenSocket' was declared 'extern' and later 'static'
net.h:479:15: error: previous declaration of 'hListenSocket'
make: *** [obj/nogui/net.o] Error 1

Any recommendation for how to fix this?

I tried commenting out those lines of code in net.h and now I'm getting:

db.cpp:534: undefined reference to 'AddAddress(CAddress, long long)'
net.cpp:1363: undefined reference to 'AddAddress(CAddress, long long)'
main.cpp:1914: undefined reference to 'AddAddress(CAddress, long long)'
init.cpp:493:  undefined reference to 'AddAddress(CAddress, long long)'

could this be an issue with the libraries I've installed? I followed the doc pretty much verbatim.


texts: I'm in the uk, I wish to purchase bitcoins, but the process seems to be very convoluted. There has to be an easy way?

texts: Any way that doesn't involve days of delay, verification etc? Are private traders available?


texts: How do I pay Utility Bills anonymously with Bitcoin?

texts:
I can get my salary with Bitcoin: https://bitwage.com/
I can get loans with Bitcoin: https://bitbond.com/
Can I pay my utility bills with Bitcoin? If the naming pattern follows, there's a https://bitutility.com out there for me. I just haven't found it, yet.

So far, I've found bitwala.com, but I can't tell if they require a name on the payment.

Say, hypothetically that a Bitcoin user had reason to ensure his name goes with his physical address on as few documents as possible.

Assuming that a Bitcoin user has a pseudonymous account, how can that user, in general terms, use Bitcoin to pay utility bills with Bitcoin anonymously?

Alternatives:

Anonymous PayPal
One of those $200 prepaid VISA debit cards
Cash at the Utility's office

I imagine that the issues are mostly logistics, as the companies do not care who pays a bill as long as it's paid, right?


texts: What is the significance of Bitcoin Pizza Day, and when is it celebrated?

texts: Today, at Consensus 2017, some people were talking about getting Pizza to celebrate Bitcoin Pizza Day. What is the  story behind  that, and when is it celebrated?


texts:
I just purchased a pair of CryoBit cards and it occurred to me that, while I know how to send money to a cold storage wallet, I am not exactly sure how to send money out.  I assume I import the private key into an online wallet, like BlockChain, and then do a full sweep to another address in the BlockChain wallet.

But if I import the CryoBit private key doesn't that expose the private key on my CryoBit card, reducing the full trust of that card?  I've read on other answers that once a cold storage private key is imported into an online wallet that wallet should never be used again...  At $30 per CryoBit card that seems like an expensive waste to discard the card after one use.

Also, if I do import the private key on the CryoBit card into BlockChain, do I have to do a full sweep or can I just send some of the CryoBit private key funds out?

Say for example I have $1000 on my CryoBit card and I import the private key into BlockChain.  Then I send $500 to an external address leaving $500 on the CryoBit address.  Then to clean up the cold storage I delete the private key from BlockChain.  Will I still have a trustworthy cold storage wallet in CryoBit with the remaining $500?


texts:
Is the following scenario valid?

Some unhonest segwit mining pool takes top-1000 segwit utxo and mines a block at height N with a transaction which transfers all funds to his p2pkh address
This block does not have segwit data portion, but it can be broadcasted to all non-segwit nodes on the network
All other pools have a dilema - wait the segwit data associated with this block or start mining block N+1 on the top of N
What if miners will use SPV-mining on the top of this block? They will create blocks at heights N+1, N+2... etc without checking the segwit-validity of block N

Also asked here: https://bitcointalk.org/index.php?topic=1434842.0


texts: Transaction validity clause: output must exist

texts:
I'm reading through the Mastering Bitcoin book and the section talking about what nodes check for to ensure a transaction is valid before accepting it refers to this:

  Each node verifies every transaction against a long checklist of
  criteria:

  ...

  For each input, the referenced output must exist and
  cannot already be spent.

However, I'm not sure exactly what it means for "an output to exist". How can an output exist if I am creating it now with this transaction?


texts:
Does the Bitcoin protocol guarantee that within a valid block, if transaction B spends the outputs of transaction A, A will always precede B?

Or is it possible to have B before A?


texts:
I'm pretty clear on how a Bitcoin mixer obscures transaction history, but I don't understand how an observer is not able to reasonably link the source and destination wallets simply based on the transaction sizes.

Example,

I deposit 100 BTC into a mixing service's wallet
Over some time the mixing service places 100 BTC into another wallet
I have created.

If an observer has some interest in tracking me, they can view all wallet balances and determine which have had 100BTC placed into after my initial transfer to the mixing service. Assuming I don't use the end wallet for any other purposes, an observer simply needs to look for all wallets where about 100 BTC was deposited in them recently. This is probably a small list, and becomes even smaller as the amount to launder grows. If I wanted to launder 10000 BTC through a mixer, there are probably very few wallets that will have this amount deposited into them over such a short period.

The answer seems to be, "keep transactions small when mixing" but in a network where there is not much activity (compared to fiat currencies) it seems like tracking down laundering activity isn't very hard.


texts: How does merkle tree verification of transaction work?

texts:
From what I have read, suppose B sends 1 bitcoin to C. C wishes to verify B's payment and asks C for the block number (location) that input transaction is located at. (Is this correct understanding/procedure?) Then C checks whether transaction is actually in the block mentioned using Merkle tree.

And this is where my understanding stops. I know that Merkle tree has nice property such that if one has transaction itself and some trde hashes, you do not have to check all subtree hashes to check validity of transaction in the block. But this still requires receiving hashes from full node that knows what transactions are in the block. If all C knows is the block number plus transaction, then how is this different from just receiving the answer yes from the full node? The full node would still have to search where the transaction is located at the merkle tree in order to send subtree hashes. I just do not see how merkle tree helps to verify efficiently.

But given the level of my confusion, I do think that it may be better to answer by giving detailed procedures on what happens when B sends bitcoin to C.


texts: How do I get to scan QR code to get private key of a "watch only" blockchain wallet address?


texts: Is the bicoin: URI scheme an URL scheme as well?

texts:
Hi given that bitcoin:1335STSwu9hST4vcMRppEPgENMHD2r1REK is a valid URI. Is it a valid URL (locator!) as well?

I tend to say yes when I compare sending bitcoins to a bitcoin: URI with sending mails to a mailto: URI. The latter is according to RFC 2368 an URL scheme.


texts: Segwit Address Supporting Testnet Faucet

texts: Looking for a good Segwit supporting testnet faucet and preferably one that supports P2WPKH addresses, however answers that allow only P2WSH are fine too.


texts: connect to bitcoind from docker container

texts:
I'm trying to connect to bitcoind from a docker container in order to generate new addresses. I keep getting connection refused message.
I saw a solution saying that i have to change bitcoin.conf file to allow all ip addresses to make it work but i think it's dangerous.
What do you think?


texts:
Installing bitcoind from github, I forgot to pass "git checkout v0.8.6" (current version at time of writing), and of course, go the following error in getinfo.

"This is a pre-release test build - use at your own risk - do not use for mining or merchant applications"

This got me thinking, what kinds of unexpected problems which could happen?


texts:
Best regards

I have been doing a lot of research about bitcoin and blockchain. A lot of informacion across the Internet can be found where many people explains the basics of bitcoin an it´s underlaying technology, but I have a question that I can´t quite find the answer and beg for this community help

If one searchs in Google Almighty one can track down bitcoin to the first block issued which is told  to have the hash:

000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f

on Blockchain.info the transaction info made is available:

https://blockchain.info/block-index/14849

And I even found a blog where the original block data containing the now famous ¨The Times 03/Jan/2009 Chancellor on brink of the second bailout for banks¨ is given

https://en.bitcoin.it/wiki/Genesis_block

But, to which data I have to apply SHA256 in order to get the given hash?

Many people say that is to block header copossed by Version - Previous block hash - Merkle Root - Timestamp - Difficulty Target - Nonce in the block structure, but another question arises for me:

When a pool is mining, does it receives the block info and its hash? From who receives that data?

Hope you can help me, any readings/books/videos/resources you can recommend will be appreciated or threads where this question has already been answered!

Thanks in advance!


texts: Is there a solution to paying high fees when opening and closing lightning channels once we hit a fee only market?

texts: Paying several hundred dollars to open and close a lightning channel seems uneconomical. This is a common argument against lightning by big blockers, I’m yet to read a valid argument against this.


texts: Wallet not updating with balance and database error

texts: I'm fairly new to using bitcoins and have been having some trouble with my wallet. I bought bitcoins on coinbase and transferred them to my bitcoin core wallet. The transaction was confirmed with 616 confirmations, but it has been several days and the balance has not shown up in my wallet. At the time, the wallet was was synchronizing with the network for what must have been a total of 24+ hours and was less than half way there. Last night, before it was done synchronizing, I got a database error and now it's "Reindexing blocks on disk" and is 3 years behind. Are my bitcoins lost or will they be visible in my wallet once my wallet is done reindexing?


texts: Is there a fast way to send bitcoins to an address on a web page?

texts:
I'm looking for something like a browser extensions that makes it possible to easily send bitcoins to an address on a web page.

I don't think a bitcoin:[address] URI protocol already lifted off, otherwise it would be ideal. But as long as it doesn't, a browser extension would be good enough...


texts: Is there an open database to query bitcoin transactions

texts:
My goal is to get all addresses with a balance of more than 0.01 BTC. In order to get this data, I have to sync the full bitcoin node but I want to avoid it. Maybe there is any open SQL or MongoDB database somewhere. The speed is important.
Thanks in advance


texts: Can Multibit be used as an offline cold storage solution similar to a setup with Bitcoin-QT?

texts: Currently have my cold setup offline in Bitcoin-QT. Downloading the blockchain from zero is rough. It's time to update. Can I create a similar cold storage solution with Multibit? Will this speed up load time when I bring coins online thru Multibit?  Are there any other benefits or weaknesses that you can think of with a Bitcoin-QT cold solution vs. a Multibit cold solution?


texts: Why the blockchain isn't just a Merkle tree

texts: I am reading this and now wondering why the blockchain isn't just implemented as a Merkle tree, or the reverse, why you can't just have a single data structure (i.e. a transaction chain) instead of the block chain with nested Merkle tree of transactions.


texts: When the number of bitcoin reward halves after 4 years, doesn't the perceived value of a bitcoin about double?

texts:
Let's say the price of a bitcoin is US$33,000, and all the miners mine it or not mine it if their electricity kWh price is too high, and it is at an equilibrium that it is somewhat profitable and worthwhile for the miners to mine bitcoin.
Then in year 2024 May, when the rewards changes from 6.25 bitcoins to 3.125, and if the price of a bitcoin stays at $33,000, then it become unprofitable for many miners, and they would stop the mining, and for all the miners to still keep on mining, they would think that the price of one bitcoin is more like $66,000 as before. So would the perceived price of a bitcoin double every time the reward becomes half?
Or would the price just stay low, but just that all of a sudden, a portion of the miners would stop, but when it becomes easier to "win" the block every 10 minutes, some miners will join again, until it reaches an equilibrium around this lower price?  But it seems many miners would think, it is so difficult to mine and be profitable, and therefore they are not selling their bitcoins at $33,000 but would demand a higher price.


texts: Privacy. How to prevent transaction recipient tracing prior transactions of mine

texts:
I am thinking of sending some BTC to a new BTC address, but do not have complete trust in that new one.

I'm sending to someone else, but want to be sure that if I do, they can't access other people I have used the same BTC wallet to send BTC


texts: I'd like to create a 3d representation of the market depth graph (of BTC/USD) over time. (the graph here https://www.bitstamp.net/market/order_book/) I think it would provide a nice representation of buy/sell walls and price (the trough in the middle) over time. Where can I download this data? A list of all trades won't work, but open orders over time would.


texts: Integrate Bitcoin price in Google Sheets through Google Script

texts:
How can I integrate the real-time value of the BTC/EUR pair to a Google sheet? What script can I use?

For ETH/USD I use Poloniex and a script for that, but there is no BTC/EUR pair on Poloniex.

This is the script I use for Poloniex and the ETH/USD pair:

  function getETHtoUSDTpoloniex() {
  var url = "https://poloniex.com/public?command=returnTicker";

  var response = UrlFetchApp.fetch(url);
  var test = response.getContentText();

  var myjson = JSON.parse(test);
  //var leng = myjson.data.length;

  var USDT_ETH = myjson["USDT_ETH"];

  var price = USDT_ETH.last;

  return parseFloat(price); }

Help please!


texts: Bitcoind JSON-RPC - getbalance with 0 confirmations not included

texts:
When I access bitcoind through JSON-RPC and query:

  getbalance '*' 0

It does not include transactions with 0 confirmations.

Only when a transaction has least 1 confirmation it is included in that rpc call.

Bitcoin-Qt correctly shows the number I want to get in Overview > Wallet > Unconfirmed

I am using Bitcoin 0.8.6 beta


texts: Should I try to get fuzz testing working on MacOS or should I stick to Linux?

texts: The Bitcoin Core fuzzing docs contain some hints for getting fuzz testing working on MacOS. But if I have access to a Linux machine/VM should I stick to doing all fuzzing on Linux? I'm assuming there is no little benefit to the project as a whole that people are fuzzing on different operating systems (other than expanding the number of people fuzzing Bitcoin Core).


texts: Accidentally sent to my own receiving address, will I get back my bitcoins?

texts: I mistakenly pasted my own Blockchain.info receiving address into the recipient field when I was trying to send BTC to a friend. I usually receive either a "send" or "receive" notification in my records, but this time I got a "transferred" notification. Even though it was my own receiving address it took 100 confirmations and blockchain.info never returned my BTC back to my own wallet. I'm not asking for my fees to be returned but about the whole bitcoin I sent. Do you think that I will get back my BTC even if I used my own receiving address?


texts: BOLT 11 - Why is the description field limited to 639 bytes?

texts:
Why is the description field in a Lightning Network invoice limited to 639 bytes?

https://github.com/lightningnetwork/lightning-rfc/blob/master/11-payment-encoding.md#tagged-fields

https://github.com/lightningnetwork/lnd/blob/95502da7e87d7f1ae96e9d69fcdb2f1b038d6497/channeldb/invoices.go#L85 (LND limits it to 1024)

I would like to send data over the lightning network using the description field for the anonymizing aspects of onion routing in conjunction with the economic incentive for honest nodes.


texts: Why is it impossible to derive public key from address?

texts:
This is my first bitcoin transaction.

Why this transaction doesn't show my public key? help message on the same page says that,

  It's impossible to determine the public key from a Bitcoin address,
  but if the public key was ever used on the network, it is listed here.

I was thinking that my address is public key. Is it really impossible to derive public key from address?

other details, blockchain.info transaction & address details.


texts:
I've read some literature on mixing in systems like TOR and also in Bitcoin.
In Bitcoin and Cryptocurrency Technologies, the authors explain that uniform transactions are highly important in order to prevent correlation attacks by matching inputs and outputs:

  Uniform transactions. If mix transactions by different users had
  different quantities of bitcoins, then mixing wouldn’t be very
  effective. Since the value going into the mix and coming out of a mix
  would have to be preserved, it will enable linking a user’s coins as
  they flow through the mix, or at least greatly diminish the size of
  the anonymity set. Instead, we want mix transactions to be uniform in
  value so that linkability is minimized. All mixes should agree on a
  standard chunk size...

However, I'm unable to find examples where this is visible in the blockchain.

I've also seen mixing in Bitcoin described differently, for example in the Bitcoin and Beyond paper:

  The mixing service aggregates bitcoins received from all its users to
  re-distribute them again. Some services use randomness, i. e., they
  split the amount into smaller random chunks and transfer them after
  random intervals. The user can schedule the transactions and provide
  time constraints.

Now I'm looking for examples of these types of mixing transactions in the blockchain, especially one where I can see a fixed chunk size being used.
Is one of these schemes used more frequently nowadays?

Is the second scheme really secure? If THIS is actually mixing like I assume, then isn't it possible to match sets of inputs to sets of outputs that have the amount (or slightly less) BTC value and therefore have to be connected? I can imagine that this does also work over the course of multiple transaction in case the payout of a mixer is split into intervals.


texts: Is it a relatively big fee buying Bitcoin on bitcoin.com?

texts:
I bought some Bitcoin on Robinhood for $0 fee, and about $2.99 fee on Coinbase.com, but since bitcoin.com seems like an official website, I tried installing the app to buy some Bitcoin, but for $180 of Bitcoin, the fees are like $13.50 + $2.32 = $15.82   (as paid by Apple Pay).
It seems such as big percentage (8.3%) of fees just to buy $180 of Bitcoin.  Is that just the way it is on bitcoin.com or any method to make the fees at most about 3%?


texts: when I send money from my wallet, which address shows up as "sender"?

texts:
I have not yet sent money to anyone. I was wondering if there is any way to control which address shows up in the block chain as the sending address.

Say I receive money on addresses A, B, C.
I want to send money to someone from a totally unrelated address D. How to do this using the bitcoin client.

EDIT: I want to unlink addresses (A, B, C) from D

So when I send money, the sender should be D, and there should be no transactions from any of (A, B, C) to D, directly or in a chain. I guess this is not possible without 3rd party help.

I fear that the ability to follow transactions in a chain will eventually reveal enough information about identity of users. So there should be a way to send/receive from two complietely unlinked addresses. (linked = connected via a transaction chain).


texts: When I try to download Bitcoin Core on MacOS it says "Apple cannot check it for malicious software"? Is it safe to download?

texts:
Brand new Mac Mini, latest macOS Catalina (10.15.6 (19G2021)), followed instructions on bitcoin.org download page.  Double click Bitcoin Core.app, and I get:

“Bitcoin Core.app” can’t be opened because Apple cannot check it for malicious software.
This software needs to be updated. Contact the developer for more information.

Any suggestions?


texts: LND describegraph and getnetworkinfo RPC response

texts:
The LND API documentation is here, but doesn't contain much information about what the responses to various calls mean. Can anyone explain what these responses are describing?

describegraph['edges']

I understand this to be channel data, but not sure exactly what it's describing.

"time_lock_delta": 14,
"min_htlc": "0",
"fee_base_msat": "546000"
"fee_rate_milli_msat": "10"

getnetworkinfo

"avg_out_degree": 2.841628959276018
"max_out_degree": 102


texts: Is it possible to recognize conflicting 0-confirmation transactions with the Bitcoin client or other available software?

texts:
Is there already a way to detect conflicting 0-confirmation transactions? I'm assuming at least one transaction goes to my wallet.

I would expect the client to list the transaction as conflicting but from what I understand from What does the Bitcoin client do when it receives conflicting transactions? it currently does not do so? Is there any other way available?


texts: Is a public message at blockchain.info embedded in the actual block chain?

texts:
When sending a transaction using a wallet at blockchain.info you can add a public message. This message shows up when viewing the transaction at blockchain.info.

Is this message embedded in the actual block chain or is it just a record in the database of the server of blockchain.info?


texts:
A few clarifications about running the bitcoin client (let's say bitcoin-qt) on multiple machines on a private.

Question is sort of hypothetical but I was hoping to get some insight into best-practices.

Suppose I want to share a wallet between 2 machines and have both automatically update whenever there is a send/receive.  I imagine one way to do this is to have a single wallet.dat file available on one of the machines and have both clients point to it.

Or on another server somewhere or even some cloud storage account.  So my questions are:

Is this even possible?
If so, is it considered safe or a good practice?  Should/can you share the blockchain db files as well?
Would the wallet encryption cause any issues with this?
What if the clients are running on different OS?
Any alternative non-cloud solutions ?  Like keeping it on one machine that will allow (secure) remote access from the other?

Of course one could just use a blockchain.info or other e-wallet and problem-solved.  Although that solution has its own inherent issues as well.


texts:
I'm just starting to screw around with bitcoin mining.  I've been a long time Boinc pseudo-enthusiast and so I just had to check out bitcoin mining.  I've started using bfgminer and I'm a little confused as to how its administration should go.

I get it running in the terminal and it shows me the main menu, but is there a way to exit out of that menu and keep it running in the background?  Then once it's going, is there a way to bring the menu back up to check in on it?

I've looked around for an answer to this and I haven't been able to find one yet; can anyone put me on the right track?

Many thanks in advance!


texts: Where can I get bigger amount of test BTC?

texts:
We are conducting some testing with the end users of our application and I need a bigger amount of test BTC for it. Using faucets, I can get 0.1 or 0.01 per request with captcha, but I need something around 100. Is there any place, where I can get this amount at once?
Cheers.


texts: Unconfirmed Transaction - 8days - Exchange to Hardwallet

texts: Hi All I transferred BTC from exchange (BTC Markets) to Ledger Nano. Transaction after 8 days still showing up as unconfirmed however the amount shows up in the wallet. Any suggestions or clarity on this?


texts: segmentation fault while using oclvanitygen

texts:
I'm running the following oclvanitygen version. The program crashes with corefile.
I'm unable to decode the core file. Has anyone faced similar issue, how to proceed?
Update:
clinfo has the following to say, Could this be the reason.

Device Name                                   Intel(R) Core(TM) i7-6820HQ CPU @ 2.70GHz
NOTE:   your OpenCL library only supports OpenCL 1.0,
but some installed platforms support OpenCL 1.2.
Programs using 1.2 features may crash
or behave unexpectedly

oclVanitygen PLUS v1.50 (OpenSSL 1.1.1i  8 Dec 2020)

Available OpenCL platforms:
0: [Apple] Apple
  0: [Intel] Intel(R) Core(TM) i7-6820HQ CPU @ 2.70GHz
  1: [Intel Inc.] Intel(R) HD Graphics 530
  2: [AMD] AMD Radeon Pro 455 Compute Engine

$ ./oclvanitygen -v -i -D 0:0,grid=1024x1024 -f comic.txt -o ouput.txt
Loading Pattern #1: 1Test
Prefix difficulty:             16506514 1Test
Difficulty: 16506514
Device: Intel(R) Core(TM) i7-6820HQ CPU @ 2.70GHz
Vendor: Intel (ffffffff)
Driver: 1.1
Profile: FULL_PROFILE
Version: OpenCL 1.2
Max compute units: 8
Max workgroup size: 1024
Global memory: 17179869184
Max allocation: 4294967296
OpenCL compiler flags: -DDEEP_PREPROC_UNROLL
Compiling kernel, can take minutes...done!
Build log:
....
....
<program source>:1218:1: warning: no previous prototype for function 'hash_ec_point'
hash_ec_point(uint *hash_out, __global bn_word *xy, __global bn_word *zip)
^
<program source>:1379:1: warning: no previous prototype for function 'hash160_ucmp_g'
hash160_ucmp_g(uint *a, __global uint *bound)
^
Grid size: 1024x1024
Modular inverse: 2048 threads, 512 ops each
Using OpenCL prefix matcher
Segmentation fault: 11
Grid size: 1024x1024
Modular inverse: 8 threads, 131072 ops each
Using OpenCL prefix matcher
Segmentation fault: 11


texts: Have wallet but only 1st name shows up in the Excell file where I saved code?

texts: I bought coins from coinbase and created my wallet in Exodus years ago. Now it is worth 10 times as much, but the Excell file  is now corrupt and I can only retrieve 1 of 12 keys. Can someone  fix my Excell file?


texts: How to find my transaction from root of Merkle Tree

texts: How could I verify my transaction from the root of Merkle Tree.


texts: Do I need to wait for Bitcoin-Qt to sync with the network before using GUIMiner?

texts: I'm waiting for Bitcoin-Qt to synchronize with the network, but it takes a long time. I'd like to know if I can start using GUIMiner while it's Bitcoin-Qt is still synchronizing.


texts: Downloaded and installed bitcoind--bandwidth usage gone through the roof

texts:
I downloaded the Bitcoin Core daemon on a Ubuntu 16.04 platform from the bitcoin PPA.

sudo apt-get install software-properties-common
sudo apt-add-repository ppa:bitcoin/bitcoin
Press ENTER to continue

sudo apt-get update
sudo apt-get install bitcoind

Set up the Bitcoin daemon to auto-run.

nano /etc/systemd/system/multi-user.target.wants/bitcoind.service

Entered these instructions to the file:

[Unit]
Description=Bitcoin Server
After=network.target
After=syslog.target
[Install]
WantedBy=multi-user.target
Alias=bitcoind.service
[Service]
User=bitcoin
Group=bitcoin
Start=main service   (was a missing = in the original script)
ExecStart=/usr/bin/bitcoind
ExecStop=/usr/bin/bitcoin-cli stop
Restart=always
PrivateTmp=false

Looks as if the program has been installedd since I get this output from the following command line:

snerx@snerx:~$ systemctl status bitcoind
● bitcoind.service - Bitcoin Server
   Loaded: loaded (/etc/systemd/system/multi-user.target.wants/bitcoind.service; bad; vendor preset: enabled)
   Active: active (running) since Wed 2018-04-18 12:06:30 AEST; 17min ago
 Main PID: 4283 (bitcoind)
   CGroup: /system.slice/bitcoind.service
           └─4283 /usr/bin/bitcoind

Apr 18 12:06:30 snerx systemd[1]: Started Bitcoin Server.

That's all well and good. For the time being I'm not interested in downloading a full bitcoin blockchain but it appears that it must be doing so since after the install a full month's worth of bandwidth (200 GB) got eaten up in a 24 h period. And it looks as if something similar is going on still when I fire up my Ubuntu machine. Bandwidth usage has gone from KiB/s to MB/s and is going to drain the household internet budget very rapidly.

What is this Frankenstein monster I have installed?

I have since got an unlimited download internet account and have got a blockchain node up and running. I used the following command to install Bitcoin Core v0.16.0:

$ curl https://bitnodes.earn.com/install-full-node.sh | sh

Downloading the full node using the Bitcoin Core GUI was quite an epic, taking 9 days in total to catch up with 9 years and 18 weeks of blockchains (180GB)--much downtime from internet connection shutting down overnight. At a mere 13.6GB, downloading the full testnet blockchain with the bitcoind -testnet -daemon command was a much less time consuming proposition.


texts: How to raise the bad-txns-vout-negative error?

texts:
I wanted to replicate the bad-txns-vout-negative error scenario. I tried the following but getting 'Amount out of range' only:
Here is the command i tried:
bitcoin-cli -named createrawtransaction inputs="[{\"txid\":\"af7cc9204d0ab7d52f66a5dacb79b77c34c90013e3288a391557ee8e07c3c307\",\"vout\":"0"}]" outputs="{\"data\": \"6e636861696e20626974636f696e207361746f73686920766973696f6e\",\"myTmAe67rCuJU5X1fqKiEYohb53TEQrxP3\": 6.249996,\"mt8QSx6m6Fwqt8zMVcji16UiVYS8xYRwFi\": -0.001000}"
error code: -3
error message:
Amount out of range


texts: How can one figure out what version of Bitcoin-Core is used most?

texts: Where can one find statistics on how many nodes are running older Bitcoin Core versions or alternative clients?


texts: One time paid or open-source Bitcoin exchange

texts:
Which is the best cryptocurrency exchange on the market?
It can be one-time paid or open-source, no PHP projects, no outdated, no decentralised like forkdelta.

I found BlinkTrade, which seems work only with BlinkTrade API. https://blinktrade.com/

Peatio seems very hard to integration and outdated. https://github.com/peatio/peatio

Coinffeine, I am not checked this deeply. http://www.coinffeine.com/

ViaBTC have open the server, but not full code. https://github.com/viabtc/viabtc_exchange_server

Seems there is out some system, which are using many exchanges - like Bittrex, etc. Many seems very similiar.
Can you maybe mention some exchange source, which you think is preatty good.
I can pay for code as well with reasonable price.


texts:
I receive these variables from the mining pool:

job_id, prevhash, coinb1, coinb2, merkle_branch version, nbits, ntime, clean_jobs.

What must I do with them?

Can you write step by step formulas how to solve that problem?

What must I respond to the pool?


texts: understanding timestamp from blockexplorer.com

texts:
What is the timestamp used for the blocks on blockexplorer.com
For example block 233969 has:
Time: 2013-04-30 23:27:36

is this time converted to 32bit hex for hash calculation, if so how ?


texts:
Trail orders are extremely useful, much more so than simple stop loss orders. Are there any exchanges that offer trail orders?

Using a trail order, the stop price would track the market price as long as it goes in the same direction, but not if the market price moves in the opposite direction. For example, say BTC is bid 250 USD and I place a trail stop (sell) order for 10 USD below the bid price. Here's what happens if BTC moves:

start => my trail order will have a stop of 240
BTC bid 260 => my trail order will have a stop of 250 now
BTC bid 265 => stop 255
BTC bid back to 262 => stop 255 stays in place
BTC bid 268 => stop 258
BTC bid 263 => stop stays 258
BTC bid tunnels down to 255 => market SELL order triggered as soon as the bid went <=258

As of June 2013, Tradehill does not offer stop orders.


texts: How does bitcoin prevent this network splitting attack?

texts:
How are malicious nodes prevented from, after getting the nonce of a new block found by someone else, broadcast it to the other nodes claiming it to be its?

Also, how does the bitcoin system solve the situation of an evil miner who has found the nonce of a block and then sends it with 2 different nodes, each one reaching 50% of the network, therefore having a problem of ownership of this work?

Finally, if all nodes have to check a broadcasted nonce to prove it's legit, how does the network defend against attacks in which thousands of ip adresses (e.g. botnet) start sending wrong nonces, causing a cpu DDoS because of all the peers hashing and checking these nonces.

Thanks for the answers.

Note: As the three questions are related I thought that putting them all in a single question was correct, if not told me and I will edit the text to only contain the first question, placing the other two in different questions.


texts: How to create an application which constructs a transaction using `bcoin` (javascript)?

texts:
I am new to development. I am working on a project and I am trying to use bcoin.
I want to create an application which has a UI, where the user will be asked to enter Destination address and amount. And maybe the sender's public key as well, if it is not already entered.
Then the application will fetch the UTXOs relevant to the sender's public key from some other Full Node.
And based the UTXOs and the input data entered by the user, my application will construct a transaction HEX.
I need the final outcome in XDR format. But I will try to do that on my own.

I will not be connecting to the Bitcoin network, I will connect with another network which has forked bitcoin code.
I know this is a very silly question. But if anyone could guide me towards the right path on how to accomplish the above.


texts: When running a Lightning Network hub, who pays the fees when a transaction has to be broadcast to the blockchain?

texts:
I've been educating myself on how the Lightning Network protocol works, and I have some questions.

Let's say that a user sends a small payment to someone and it makes multiple hops through the network before reaching the recipient. The payment then propagates backward through the chain until it reaches the payer, and everything settles out.

It's possible that a node in the middle either either intentionally or unintentionally does not pay the next node down the line. The recourse is for the node that did not get paid to broadcast the transaction to the blockchain (and close the channel?).

Who pays the fees for for that transaction? What happens if the fee is significantly larger than the amount of money the node would gain by broadcasting the transactions?

This seems like it could potentially be a large attack vector. Is there something I am misunderstanding?


texts: Bitcoin daemon sends "Empty reply from server" when in test net

texts:
I'm trying to work with the bitcoin daemon and rpc.

Using the user & password I set I can't connect to it, trying with curl I always get "Empty reply from server".

It works just fine in the real network, I can connect, getinfo, etc, etc...

Is there something I might be missing? the output log in the daemon only shows:

accepted connection 190.xxx:62470
disconnecting node 190.xxx:62470

Thanks!
Javyer


texts: MY bitcoind is on: http://207.12.89.181/ yet I cannot connect via any port, I've tried 8333 and 8332 any reason why? it's a ubuntu server. Im using that server to connect to from another server.


texts: From where can I import live cryptocurrency market values into my webpage?

texts:
I am planning to build a webpage where a user can enter his/her stock of various cryptocurrencies, and the webpage should display the current market value (in USD) for each of the cryptocurrency he/she has chosen.

I was wondering from where (which website/database) I can import the live market value for cryptocurrencies, so I can use the values in my website script?

Thank you very much in advance.


texts:
I sent 2.2 bitcoins using the old version of multibit application (0.5.18)

The commission is not calculated correctly. Therefore, the transaction can be confirmed forever.

What can I do to cancel a transaction?

I read about a "double-spend" and other solutions to the problem, but what should I do step by step (because I used a multibit).

Try to export keys and install bitcoin core?

Is the transaction self-canceled if I do nothing?


texts: How will bitcoin survive if everyone is hoarding?

texts: It is the question since I first heard about bitcoin, ethereum and then many others. Most tokens or crypto currencies, usually offer a utility on their respective platforms. Bitcoin is to distrupt traditional payment networks. But if everbody holds bitcoin for speculative reasons and never makes transactions with it, then how can it become a payment network? In that case, how can we suggest that bitcoin has an intrinsic value at all? Same holds for ethereum and many ethereum based utility tokens. For example, insurex claims to decentralize insurance industry and people hold their token in hope for the network will indeed grow. But then if they dont use the tokens for insurance transactions how could it happen? Finally, if everybody holds ETH for speculative reasons and not develop decentralized platforms, how could it become of the new internet?


texts: How would Bitcoin's purchasing power be measured after fiat were gone?

texts: Somewhere in the possible near/far future when there might not be any major fiat anywhere. What will Bitcoin's purchasing power be measured in?


texts: Miners forego revenue in order to 51% attack the Bitcoin protocol by rejecting blocks

texts:
I was recently listening to Mike Green and Anthony Pompliano debate the future of Bitcoin on RealVision. And Mike raised an interesting point regarding Bitcoin (I'm paraphrasing). "Scenario: Let's say the majority of miners, which are no longer bound by financial incentives, decides to attack the Bitcoin network by continuously rejecting blocks, could they do it? Could you essentially reject-spam Bitcoin's network?"
That, I found to be an interesting question to which I haven't been able to find an answer. Is anyone able to shed light on the plausibility of this scenario?


texts:
So I am in the process of downloading the blocks after installing bitcoin on my ubuntu server. I have followed the guide on https://bitcoin.org/en/full-node.

Everything is working correctly. Blocks are downloading just fine to ~/.bitcoin/blocks. bitcoin-cli commands are working without error.

If I switch users and I try to issue a bitcoin-cli command naturally I get "Could not locate RPC credentials. No authentication cookie could be found, and RPC password is not set."

However when using the correct user where cli commands do work, there is still no bitcoin.conf file inside ~/.bitcoin/ As the node is downloading the blocks and the cli commands work I assume there must be a conf file - yet its not where every single document and support answer claims it will be.

I have tried find . -name "bitcoin.conf" in the ~/.bitcoin directory as well as user ~/ and in /etc all return empty. Where else could this file possibly hide? If it doesn't exists why would I still be downloading blocks and able to issue cli commands?

I am aware this question has been asked countless times but i cant find any answers relating to the fact the node is working and cli commands are working.


texts:
What is the maximum size for an input script so to be considered standard ? Looking at the Bitcoin Core source code it appears to be 10'000 byte, however reading here and there, it appears to be 1650 byte.
If that's the case, if the input script is redeeming a P2SH, is the size of the redeem script (520 byte) to be considered in the count, or not ?
Thank you very much !


texts: What are some essential features of Bitcoin classic?

texts: I already know about the 2MB block size increase. I would like to know more about who controls the code base, what the other proposed changes are, and those kinds of things.


texts: Issue with bitcoin client 0.4.0 - stop populating

texts:
My bitcoin client stops populating at 8 connections and 112949 blocks, event I left it running for over 12 hours now. I checked my internet connection and firewall, all seem OK. Restart it a few times still make no different.

Appreciate any suggestion.


texts: Withdrawal from Freebitcoin to my Bitcoin Address

texts: I have recently withdrawn bitcoins from freebitcoin and i used my bitcoin address, now i want to know where can i access/see that transaction ?


texts: What does setting up a Trezor actually do?

texts:
About a month ago, I set up my Trezor device: set the device label, wrote down the recovery seed, set the PIN, and added a passphrase. But, I never sent any money to it.

What did I do? Did I basically just use my Trezor to generate a random number?

I'm asking because I lost my PIN, and I left my recovery seed in plain view, so I'm concerned someone may have seen it.

Is it OK if I just wipe my Trezor; shred my recovery seed, PIN, and passphrase; and start over? Or, will I lose more (from the initial setup) than just a random number (and the device label)?


texts: How can someone verify the signature of a Bitcoin ECDSA signature without knowing the signer's public key?

texts:
I understand how ECDSA exactly works and for verification of a signature, the public key of the signer is required. But in Bitcoin, public key is double hashed and the only information the receiver knows is the sender's address.
Then my question is that how the receiver can verify the senders signature without knowing his public key?


texts: What are the advantages and disadvantages of pooled mining?

texts: Is it better to mine solo? Is pooled mining what is recommended now? I've heard you get about the same back either way, but I am confused and would like some help.


texts: How easy is it to solo-mine new altcoins?

texts:
It seems to be pretty clear that CPU/GPU mining is obsolete for the big fellas (Litecoin, Bitcoin, Ethereum, arguably Dogecoin). This is a bummer for beginners like myself cause I'm keen to dive in and get my PC grinding away at the digital coalface like it's 2009.

I've decided that I want to mine a bunch of altcoins and completely disregard short-term profitability (mining BTC wasn't profitable in 2009, but look at how much it's worth now!).

My actual question: Exactly how does one go about solo mining altcoins? Is the process the same as mining bitcoin, litecoin, dogecoin, ethereum etc? What program do you need to download and how easy is it to configure? I ask because I have had zero luck even getting set up with mining these more mainstream coins. I was really hoping for a "download program, punch in your wallet code and go" situation, but instead I've had to muck around with mining pools and heaps of complicated settings and I can never get it working. Some guidance would be appreciated


texts: How are MtGox options going to affect Bitcoin price volatility?

texts: MtGox plans to introduce Options, would Bitcoin price become more stable or it would just hedge risks?


texts: Transactions from Bitcoin-qt wallet not entering the mempool

texts:
I bought some BTC a few years ago and they've sat in an old Bitcoin-qt wallet (0.8.5) on a USB drive ever since. I'm hoping to transfer them out into Coinbase or something similar, but none of my transactions seem to be entering the mempool. On the wallet, they appear as having left but have been stuck at 0 confirmations for over a week, but if I look the transaction ids up on blockchain.info (9def5314cd193eb375634fbbddb2ff07bb5db9710311b1afe4b0c531db949b57
 and 10239862eb947b6194920045423ac1a1e75c8a9bb7bbd0e87b4c8676a2656457), it says they don't exist, which makes me think that they've not actually gone into the mempool.

The first transaction had no fee associated with it (don't hate on me - I've not actually sent any BTC before, and this was the default on my wallet), which is what I assumed the problem was. But when I tried again it should have had plenty to get confirmation quickly. I've tried using the getrawtransaction command from the console to get the hex and broadcast it using /pushtx: for the first transaction, it says the minimum relay fee wasn't met (fair enough), but for the second it returns "Missing parents for [txid #2 (with fee)] while inserting [txid #1 (without fee)]". This means very little to me. If I check my wallet address on blockchain.info it still has the original sum associated with it.

Apologies if this has been asked before (I have been looking for over a week and haven't found it if so!), but I'm at my wits end and could use some help. I'd be very happy to make a donation to anyone who can help me unlock my BTC as a token of my gratitude.

Thanks in advance!


texts: What a completely-decentralized cryptocurrency might look like

texts:
It occurred to me that a more useful cryptocurrency would be one which didn't require a network to validate transactions. It would consist of some kind of (self-mined?) token that can be proven to be unique and to be "owned" only by the holder and likely be associated with a wallet. Spending it would simply change the token so that it's associated with a different wallet. Something like this might be even more fungible than a fiat note having a serial number.
Has a white paper been released describing a token which precludes doublespending without needing a network, at least after it is initially created?


texts: Can a Non-Segwit Miner mine segwit transactions?

texts:
I understand that non-segwit nodes interpret segwit txes as Anyone-Can-Spend txes, and they cannot validate txes that spend segwit outputs.

But when an old style miner receives a segwit tx to mine he consideres it invalid, right? (That's because it appears to them as a strange transaction with no input and 1 output.)
So, does it follow that segwit txes can only be mined in a block by upgraded miners?


texts:
First of all, this is to bring awareness of how an attacher may gain access to a persons' Blockchain Wallet:
 i hope this never happens to anyone else but it probably will. i am quite new to bitcoin, like probably a month. I feel stupid, no one need remind me.
what happened is this:
 i was on fb asking questions about a transaction i did to a third party that was pending for like 2 days, and the other person still hadnt seen it yet in their account so i was worried.  so i was asking about this happening etc.  and a person on fb commented it wasnt unusual to take a while for transactions to process.  so start private messaging, asking all sorts of questions. says he works for blockchain. And then he says this" blockchain wallet is starting to do mining with the extra funds in a wallet but it is only available in certain countries, not in the us yet, due to regulations. so we talk on, he says he can set up a new blockchain wallet to also do mining with the extra funds even if i live in the states.  then if i want i can fund it. so i create the wallet with no btc in it, and send him the identifier and pw. he was supposed to do some settings to it to access the mining aspect,, and i log back in, change the password,,  and fund it, i see the balance in the new wallet and after few seconds balance goes to zero.  he says that is because it is now in the mining side of blockchain. then he says, add more btc to see what the proceeds are from the mining.  i am starting to realize right then i had been scammed.  he kept saying no, just add more btc to see the balance, etc.  it went on like that for a while. i was out a few hundred dollars. what I think what he did was sink his smart phone to the account and it stayed sinked to the account, even though i changed the pw.  or perhaps there was some crypto-key he accessed and was then able to take the money out. i still dont really know. but i think BLOCKCHAIN Wallet should plug that hole !  so it doesnt happen to more people...  so i have changed a bunch of my passwords, etc, hoping that's the end of it. i had my cellphone listed in the verify section etc. so i went in and put in another number hoping that stops anything there. after this, i really had to re-think bitcoin and how easy it was to get scammed. i would say i was very tired, been working some long hours, and was worried about the other transaction going thru. i know there is no way to get it back, just have to take the lesson, but i want to make sure there are no other doors for this guy to walk thru since he got that information. also, he would have had the private key off the log in and just got it that way somehow.. Something Blockchain could do that would have prevented this: Not to allow more than one incidence of the wallet being open at once, or Notifying the user when more than once incidence is Open.
 Has anyone else been scammed , please share what happened  ?


texts: Reliability of Auroracoin distribution model based on Kennitala (Iceland National Id)

texts:
How can the Auroracoin distribution verify that the recipient does not receive coins using the id of somebody else?

If Icelanders use their ids everywhere then many Icelanders potentially know another Icelander's id.

Does Aurora restrict each Icelander to have only one Aurora address per Icelander id?

Does Aurora filter the Icelanders' locations by IP address?


texts:
What is the best practice to deal with inactive channels?

Do they have an impact on my node's 'reputation' somehow, should I close them after a few days of being inactive?

What happens if channel funding fees are involved?


texts: Is there a way to access Ethereum Smart Contract's variables by name in JavaScript?

texts:
Say I have a simple smart contract:

contract Simple {
    string32 message;

    function Simple() {
        message = "Hello world!";
    }
}

How can I easily access the message variable by name in JavaScript? It looks like there is some way to map functions into JS, but variables appear to only be accessible through a complicated way:

var storageObject = web3.eth.storageAt(contractAddress);
document.getElementById('fullName').innerText = web3.toAscii(storageObject['0x']) + ' ' + web3.toAscii(storageObject['0x01']);


texts:
I have a two KNC Neptune miners that I can no longer log into, as I don't have a record of the username/password.  In order to correct this, I need the executable firmware update files in re-order to re-flash them using the SD slot.
I CANNOT login to the neptunes via the network, so I CANNOT update using the .bin files (like as https://github.com/KnCMiner/images/tree/master/Neptune) on the miner configuration webpage.  I'm aware of these files, but I cannot use them.  Instead, I need the files I can put on a SD card and update the board that way.
Does anyone have those executables still?


texts: How to find out if LND opening pending channels has a confirmation onchain?

texts:
After typing lncli pendingchannels I get a channel_point number, and when I put channel_point txid to check if it was confirmed onchain
by typing:

bitcoin-cli gettransaction "txid insert"

I get an error:

error code: -5
error message:
Ivalid or non-wallet transaction id

How can I  see if whoever opened (pending state) channel to me has a confirmation on chain?


texts: How to calculate and spend funds received from derived addresses

texts:
Assume I have a xpub for path m/44'/0'/0' and I generate receive addresses from it like m/44'/0'/0'/1 to m/44'/0'/0'/n where n could get really large as time passes.
My question is:
Where does these funds really go? every single derived address has it's own value but do they sum up (likely in the higher tree level) ?
because wallets like blockchain show the total value of all generated values. what if all addresses have less than 0.2 BTC and I want to spend like 1.5 BTC .


texts: How to spend an UTXO P2SH pay-to-script-hash

texts:
Anyone knows specific instructions on how to claim an unspent P2SH TX (pay-to-script-hash) based on a redeem script? No multisig.

I am looking for node.js JS instructions in bitcore-lib or similar.

Any suggestions or help appreciated.

Thanks :)

edited:


texts: Why do people mine bitcoins when they are losing 20% a month?

texts: Why do people continue to mine bitcoins independently of their hash rate if their ROI loses 20% every month at the going difficulty rate and the exchange rate BTC/USD is at best flat?


texts:
I have a buddy who I sent money to to buy a certain amount of Ripple. For one reason or another, I couldn't do this on my own at the time. In any case, the currency has tripled and I want him to send the ripple to my wallet. Does this transaction require me to pay taxes on the capital gain that has occurred? Or can I simple put this ripple into my wallet.

Any help here would be great. I have called around to no avail.


texts: getrawchangeaddress: dial tcp [::1]:8080: getsockopt: connection refused

texts:
I am using the decred atomic swap, and no matter what port I set the testnet to use, it says connection refused. I backpropagated the dependencies and everything seems to be working properly, what is poassibly causing the block for the tcp connection?

All help and advice is appreciated :)


texts: Share private data and prevent data forwarding

texts: Let's say A has some private medical records of patients and B is a pharmaceutical company who wants to view medical records from A to find out the effect of a particular drug on the patients (run a drug evaluation logic to get performance statistics of a particular drug). A wants to share the private data to B but wants to prevent B to forward (leak) the data to other third party organizations. How can this problem be solved with blockchain?


texts: What is needed to create a pool with merged mining?

texts:
What is needed to create a new pool with merged mining?  (Bitcoin, NameCoin, and possibly others)?

I'd like to create a new pool that will

Include transaction fees in the payout
Charge no pool fees
Hosted on Amazon (Low latency)
Do merged mining if that doesn't create any inefficiency

I'm mostly interested in software, or general knowledge that will get me started in the right direction.


texts: Would an optimization proof-of-work problem where the entity with the lowest hash wins have any security weakness or other disadvantage?

texts: I am wondering if there would be any security deficiencies if cryptocurrencies such as Bitcoin were to change their proof-of-work problems to optimization contests. For example, suppose Bitcoin were to change its proof-of-work problem to an optimization problem. In this scenario, the goal each instance of the proof-of-work problem would be to minimize the output of the hash function, and the winner of each block is the entity who finds the input with the lowest hash after 10 minutes. Would an optimization proof-of-work problem cause any security weaknesses, other deficiencies, or complications for the cryptocurrency? Are there any cryptocurrencies which use an optimization proof-of-work problem instead of a search problem as a proof-of-work?


texts: What are the optimal cgminer settings for a AMD Radeon HD 6670?

texts:
I'm following this tutorial for mining Litecoins, and I'm having a little hard time finding the optimal cgminer settings for my AMD Radeon HD 6670. Any hint on that?

The tutorial gives this configurations for Radeon 7950 series GPUs (which is not mine):

timeout /t 30
setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_USE_SYNC_OBJECTS 1
cgminer --scrypt -I 19 --thread-concurrency 21712 -o stratum+tcp://coinotron.com:3334 -u [USER] -p [PASS]


texts:
Possible Duplicate:
  What protection does Bitcoin have against Denial of Service (DoS) attacks?

Assume I am a malicious user, and my goal is to make bitcoin unusable.
I can simply make millions or even billions small transactions between a few of my accounts. (This for sure can be automated, and these transactions are for sure legit?)
Since bitcoin tracks every single transactions, is it subjected to DOS attack?
The size of the transaction table on each client will eventually get huge and impossible to query or performance more tasks???


texts: Why does blockchain.info show a different balance from bitcoin-qt?

texts:
I just created a wallet on blockchain.info by importing my wallet.dat from Bitcoin-QT. My Bitcoin-QT shows a balance of 3.991 BTC, while blockchain.info shows a balance of 3.016.

Where does the difference come from, and which one is 'correct'?


texts: Is it possible to force a person to honor a conditional promise-to-pay?

texts:
I'm thinking of the situation where you have an auction where bids are placed. There are two conditions that should be held:

Placing a bid shouldn't expose you to paying the seller unless you win the auction
Placing a bid should require that you pay the selling in the case you win the auction

Is it possible to satisfy these two conditions using bitcoins?


texts: Why do we need 2F prepare certificates instead of just F+1 in PBFT?

texts:
I started reading PBFT and I could not understand: why do we need 2F prepare certificates?
The client needs only F + 1 replies, not 2F, so why can't the same rule be applicable in the prepare phase of the protocol?
Same question in the commit phase, but this time it is even weirder: we need at least 2F + 1, again why not only F + 1, I just know that the quorum intersection must be more than 2F + 1 but we only need F + 1 replies from that quorum intersection as far as I know.


texts: What mistakes do first time contributors to Bitcoin Core often make?

texts: What mistakes do first time contributors to Bitcoin Core often make with their first pull request?


texts: What would happen if there are more blockchain imitators like Factom?

texts:
I was referring to this question.

Apparently Factom creates its own "chain" for timestamping purposes, "hashes" the entries, and then stores these hashes on the blockchain, to create an unalterable record.

What would happen if "everyone" in the world did this? Could the blockchain support a million (or a billion) more "Factoms?"


texts: What is the function to get the object of a NXT asset in javascript?

texts: I want to get an object and its variables of a NXT asset. What is the function to retrieve an object of an nxt asset?


texts: What is most efficient way to validate bitcoin target (difficulty) value in C++

texts:
I have two values

1. h = hash of the block (32 bytes long in memory representation - not hex)
2. bits (uint32_t)

To make the calculation easier we create a function difficulty such that:

auto d = difficulty(bits)

Now what is the best way to create such a difficulty function that, I believe should, return a 256 bit value?

Then I am thinking casting both h and d values into an array of type uint64_t and compare all 4 elements from msb (bit 255) to make sure the condition holds.

Is there a better way for comparing as well?


texts:
Is there an estimate on how many people in total own some cryptocurrencies?

How is this distributed among bitcoin and altcoins?


texts: Which mining pools use custom mining software? Do those pools require the users to use their software, or just encourage their users?


texts: secret sharing scheme for 3-of-5 shares (for BIP39 mnemonic phrase of 24 words)

texts:
Given a 24 word BIP39 mnemonic phrase, I would like to have a way to split it into 5 shares, so that any 3 would allow me to reconstruct the phrase (but any less than 3 would not).

This is easy enough to do with Shamir Secret Sharing, and very secure. But that requires, at the minimum, a computer, and I would rather have a way to achieve the same (or something similar) with only a pen and paper (and let's say not more than an hour's work).

Now, I don't mind it being slightly less secure, in the sense that obtaining 2 of the 5 shares makes it easier to guess any of the other 3, as long as the difficulty is reasonable (e.g. 90 bits entropy). I feel like a 24 word phrase is really entropy overkill, and a third of that entropy is, by itself, quite a lot and sufficient for my purposes.

Ideas?


texts: How to handle multiple share mining requests in solo

texts: I was testing mining algorithm for solo and noticed that server keep sending the shares to work on (semetimes every 1 sec). In case of solo mining do I need to keep mining all the existing shares I received or only take the the latest one and discard previous ?


texts: Who managed bitcoin and ethereum decision making? Who approves Bitcoin upgrades and forks?

texts:
To my knowledge in Bitcoin and Ethereum decision makings are decided by the miners and developers. I like to know who makes the final say on the approval of a change to Bitcoin/Ethereum code or process? Is it a selection of miners/developers? Or is there a consortium or a foundation that has the final say for major/minor changes to the blockchains?

How are the developers who merge the bug fixes and other changes to the main(Master) blockchain Git branch are selected?

Is most of the decision making done on random forums and by websites volunteerly deciding to participate in these tasks? Why would a website decide to show the progress of voting on a particular blockchain fork? and how to ensure that site is credible?


texts: How is OP_CHECKTEMPLATEVERIFY a scaling solution

texts:
I was wondering about OP_CHECKTEMPLATEVERIFY or OP_SECURETHEBAG as it was previously called. As far as I understand it you can commit on how to spend the coins later this way. But it doesn't enable covenants in the sense of https://fc16.ifca.ai/bitcoin/papers/MES16.pdf, right?
Tainting later transactions is probably quite controversial (and impacts fungibility). Will it be somehow possible to extend OP_CHECKTEMPLATEVERIFY to enable this in the future?

I believe there are probably some use-cases for CTV, but I don't seem to quite understand how this is a scalability solution (as it was "advertised"). After all if you do something in two-phases (first commit and then actual transactions) there is more blockchain data. The trick is just that you do the commitment when fees are high and can do the second part later (with lower fees) or am I missing some important piece? Couldn't you solve the same thing with P2(W)SH?


texts: How much trust is placed on Satoshi Nakamoto?

texts: Is the safety of bitcoin dependent on the creator of it being a trustworthy person? Or would it be safe to use even if it turned out the creator's day job was working at the NSA?


texts: How did Satoshi grow the Bitcoin community?

texts:
Is there an old record of Satoshi's first attempt of promoting Bitcoin?
Did Satoshi had initial beta testers?

What was Satoshi Nakomoto's marketing strategy? When I mean marketing as in from a technical person's perspective (programmers, indie developers), assuming that Satoshi is more on the technical side than marketing.


texts: bip39 converting from entropy to seed failing tests with entropy "00000000000000000000000000000000"

texts:
Trying to convert hexadecimal string of entropy to seed sentence with the below snippet. Failing the first test with 16 zero bytes. It seems that my function came to conclusion that checksum is '1011' yet it should by '0011' (by this page for instance) therefore I do have a mistake in seed sentence where my last word is on index 13 (accuse) and correct word is on index 3 (about). What is broken in my function? Also, there is not much of an implementation details in bip39, if you know about some resources (not just core codebase) they'd be warmly welcome!

import hashlib
import requests
import unicodedata

def get_word_list():
    url = "https://raw.githubusercontent.com/"
    uri = "bitcoin/bips/master/bip-0039/english.txt"
    return requests.get(url + uri).text.split()

def checksum_length(entropy_bits: int) -> int:
    return int(entropy_bits / 32)

def mnemonic_from_entropy(entropy: str) -> str:
    word_list = get_word_list()
    entropy_bits = len(entropy) * 4
    entropy_bytes = bytes.fromhex(entropy)
    print(entropy_bytes.hex())
    entropy_int = int.from_bytes(entropy_bytes, byteorder="big")
    sha256_entropy_bytes = hashlib.sha256(entropy_bytes).digest()
    sha256_entropy_int = int.from_bytes(sha256_entropy_bytes, "big")
    checksum_bit_length = checksum_length(entropy_bits=entropy_bits)
    checksum = bin(sha256_entropy_int)[2:2 + checksum_bit_length]
    entropy_checksum = bin(entropy_int)[2:] + checksum
    entropy_checksum = entropy_checksum.zfill(entropy_bits + checksum_bit_length)
    bin_indexes = re.findall("." * 11, entropy_checksum)
    indexes = [int(index, 2) for index in bin_indexes]
    mnemonic_lst = [word_list[index] for index in indexes]
    mnemonic_sentence = unicodedata.normalize("NFKD", " ".join(mnemonic_lst))
    return mnemonic_sentence

if __name__ == "__main__":
    mnemonic_from_entropy("00000000000000000000000000000000")


texts: How does Ripple synchronizes its ledger?

texts:
Bitcoin decides on a global clock by the blockchain - every mined block is another tick of that clock.

In Ripple, there is a global ledger that keeps advancing in time - the ledger number keeps increasing all the time, and the ledger represents the state of the system at time t.

What synchronizes this ledger? How do different Ripple nodes know when they should advanced their ledger counter?


texts: What is the best way to download a "recent" UTXO set snapshot?

texts:
I am using bitcoinj to listen for payments. I need a way to maintain the entire UTXO set in a local database.

Can bitcoinj be used to download every block (I think it downloads only recent blocks and headers for older blocks)?
I don't need to use bitcoinj or even Java for creating or maintaining this database if a better solution exists. Is there anything like this?

Ideally what I want is a wallet that downloads only the UTXO set without downloading the entire blockchain (due to bandwidth limitations) and maintains it from then onward. This needs to be the entire set, not just for the addresses I own.
Additionally I need an API that allows for following queries:

Given a UTXO, check if it is present in the set.
Given an address, get me all the UTXOs for it.

I think that it is currently not possible to validate a given UTXO set without downloading the entire blockchain, so some solution in this regard would also be appreciated.


texts: Why does bitcoin use AES-256-CBC? Why not some other block cipher operation mode? Is there a specific reason?


texts: When update mining difficulty, Is the timespan of the past 2016 blocks approximated value?

texts:
I know how to calculate difficulty, and I know it is increased or decreased by checking the timespan of the past 2016 blocks.

and I found actual code for calculating timespan: https://github.com/bitcoin/bitcoin/blob/master/src/pow.cpp#L55

actual_timespan = last_block->get_timestamp() - first_block->get_timestamp()

But, as I know timestamp in block is not the exact time of the mining:
https://en.bitcoin.it/wiki/Block_timestamp

So, the timespan which is used to calculate the next difficulty is not the exact timespan but approximate value. Am I right?


texts: Shower thought: would continually broadcasting 1mb blocks help with scaling?

texts:
Currently, when a miner mines a block, they broadcast the next 1mb block and the mining competition begins on that block.  It will take 10 mins for the block to be mined.  In that 10 minutes, the network is not being used for block transmission.  We're fully engaged in compute.

What if, at an agreed block in the future, the bitcoin protocol changed such that:

The winning miner broadcasts a 1mb block in the usual way and the network gets mining.  Call this CB (current block).
The winning miner continues to broadcast 1mb blocks every P seconds. Call these blocks NB1...N (next block)
All miners, currently busy mining CB, now are also in the background assembling a larger block from all the NB1...N blocks
Once a miner mines CB, its announced to the network, along with a new 1mb block, called LNB (last next block)
All miners now assemble a new larger block from LNB and all the NB1...N they already have, and begin mining on it this larger "goldilocks block" - a block that is just about the right size given what the network can handle in terms of throughput.

P is tuned to allow fair propagation of the NB blocks.  Lets say it's 60 seconds.  This would make the goldilocks block an effective 10MB in size.

I don't know if this idea works or not.  It's a meditation retreat thought more than a shower thought, but I wanted to bounce it off people who might know better, so, if nothing else, at least I can learn something :)

Thanks for listening.


texts: Are there any non-obvious risks to this scheme for artificially stabilizing Bitcoin's price volatility for my business?

texts:
A while back, I had an idea for a strategy to incentivize Bitcoin transactions for a business I might run. One of the primary drawbacks to using Bitcoin for everyday transactions is its price volatility, so I could perhaps do something like the following to make transaction prices more reliable:

Set prices for my goods/services in a relatively stable currency, such as USD.
When accepting Bitcoin as payment, value it at either its highest level over the past month, or at 300% of its current value, whichever is lower. (e.g. if Bitcoin reaches a high of 60,000 USD, I will value incoming Bitcoin at 60,000 USD for the next 30 days unless the price falls below 20,000 USD, meaning that someone buying with Bitcoin while it's valued at 45,000 USD gets a 25% discount).
When paying employees in Bitcoin, use daily dollar-cost-averaging throughout the pay period, but value the coins bought each day at either the lowest price during that day or 33% of the coin's value at the time of payment, whichever is higher (e.g. if Bitcoin reaches a low of 30,000 USD on a particular day, but the coin is worth 60,000 USD on payday, employees being paid in Bitcoin will effectively receive double their salary for that day).

In short, when accepting payment from customers and paying employees, I would relieve them of having to time the market and instead treat the Bitcoin prices as if they were the price in the recent past that most benefits that customer or that employee, and eat the cost difference.
Obviously, one risk with such a scheme is that the cost I eat might be quite severe (those cutoff percentages, tuned here at 300% and 33%, could cut me off from up to 89% of my revenue in USD). However, is there anything else I'm overlooking that would make this more fundamentally not work or be even riskier than that? I've never seen anything close to this proposed on the Internet, which makes me wonder if I'm missing something, though it's also possible that I'm not looking in the right places - does a scheme like this have a name?


texts: How can I find out who sent me bitcoins?

texts:
I had a very unusual situation. I received the bitcoins in my wallet, how can I find out who sent them?

Maybe it was the Creator of bitcoin ? :)


texts: How to retrive private key from MultiBit HD 0.5.1

texts:
Have a MultiBit HD wallet that contained BCH. These were transferred to a more secure environment in 2017. Have now realized that I can sweep the Bitcoin Cash that was issued 1st of August 2017 from the Multibit HD wallet. If I did know the private key. I do have the password so I can easily unlock the wallet, but I can't seem to find how to retrieve the private key. The mnemonic seed is of course long gone so I have to rely on the wallet and the password.
In Bitcoin Core its easy to retrieve the private key, just using the console. But MultiBit HD doesn't have that feature. Any suggestions?


texts: When manually creating a raw bitcoin tx, how does one determine whether the r or s values require more zeros?

texts: Supposedly, if an R or S value will equal a "negative" number, one must append zeros to it and alter the "length" descriptor for the value to reflect that.  When manually creating a raw tx how does one determine whether one's R and or S values require the addition of these extra byte(s)?  All conversions I do with a hex calculator always show positive numbers.


texts: How do I know if I have ever registered a bitcoin account?

texts: Just wondering how I could check to see if I own any bitcoins.  How can you do this?


texts: Why is there an output with op-return in regtest mode?


texts: Can bitcoins be "sold short"?  Or are there "put" options?

texts:
Borrowing an asset and "selling it short" facilitates finding the appropriate price for the asset, allowing people to bet that the asset is overpriced (e.g. in a "bubble").  Can bitcoins be sold short?  Where and how?

Update (from Serith's answer): how about put options, which are similar?


texts: OP_HASH160 and number of bytes of public key

texts:
When creating a raw transaction, why after the OP_HASH160 the number of bytes of the hashed public key should be included if it's always 20 bytes (that's what RIPEMD160 throws)?

Does this happen with every OP_CODE value in scripts?

Please explain. Thanks.


texts: Is there any full node supporting multiple crypto currencies like BTC, BCH, Litecoin?

texts: I want to use JSON-RPC protocol in my application such that it should support multiple crypto currencies.Is there any single full node supporting multiple cryptocurrencies.


texts: What is the current maximum Bitcoin block size in MB?

texts:
BIP141 specifies the following:

  https://github.com/bitcoin/bips/blob/master/bip-0141.mediawiki#block-size

  Block size

  Blocks are currently limited to 1,000,000 bytes (1MB) total size. We change this restriction as follows:

  Block weight is defined as Base size * 3 + Total size. (rationale[3])

  Base size is the block size in bytes with the original transaction serialization without any witness-related data, as seen by a non-upgraded node.

  Total size is the block size in bytes with transactions serialized as described in BIP144, including base data and witness data.

  The new rule is block weight ≤ 4,000,000


texts: how long does it take for a miner to validate account "balance" and how does it do it

texts:
My question is how long does it take for a miner to validate account "balance" is sufficient to initiate the transfer so it can include it in a block and how does it do it?
Does it iterates through the whole block chain and sums up the unspent outputs associated with the sender? Or it maintains an internal database that represents each member and their balances whose transaction was ever included in the block chain and once new transactions(a new block) is added to the block chain it updates its internal database?

I guess the second would be much faster than iterating through the whole block chain which is now over 100+ gigabyte.

I'm really interested in how the account balance is determined by the miners. Any help is appreciated. Thx


texts: Are there any websites where bitcoin holders can invest their money? Such as by buying shares or giving out loans. For example there is a ShareHolder service for WebMoney. Is there something similar for Bitcoin?


texts: Orderly Transition Away from ECC? Or Bitcoin to zero?

texts:
Let's say asymmetric public key cryptography is wide open, and can be broken using a public key or the signature.  Namely, that I can determine the private key using the information revealed in a public key or the signature.  Whether this is done with a classical, or quantum computer doesn't really matter. Let's say that this means I can steal any Bitcoin today from anyone -  whether they are yours, mine, or any other UTXO on the chain.
Now, unlike gold, which to steal requires you to do things like siege Fort Knox and have a military to do successfully, it seems like some modest cryptanalyst chaps can just sit in their pjs and steal Bitcoin during their lunch break while outside GCHQ or at a Starbucks outside Fort Meade.
So, can Bitcoin transition away from ECC in an orderly manner?
Would there be a fork (like ethereum did with the DAO) to fix all the stolen Bitcoin?


texts: Because I don't have any rep. and the chargeback issue, no one will buy my Moneybookers(USD) or NETELLER(USD). Is there an exchange that will?


texts: calling getaccount rpc method on foreign address

texts:
calling getaccountaddress method on an address associated with the default account return "" the name of the default account. The problem is calling getaccountaddress on foreign address that doesn't exist in the local wallet will return "" !

Shouldn't this method in the last case return an error or something ?

i think the solution here is to call validateaddress method to check this address ismine or not.


texts: Is there a Bitcoin equivalent to Infura?

texts:
I was wondering if there's some service for Bitcoin that is equivalent to

https://infura.io/

All I could find similar so far is blockcypher, but it appears to require fees while infura doesn't seem to require any fees.

Thanks!


texts: Converting a bitcoin miner for other use

texts: Is it possible if you purchased a bitcoin miner such as an antminer that cracks sha256 and edit the software so it could just crack normal sha256 hashes such as that you could use it with things like johntheripper or hashcat? I know us over in the hash cracking community would love to see such a great improvement in speed even if it's only for one specific hash type.


texts: Why am I unable to post two transactions (the second from the change address of the first) in the same block?

texts:
I'm attempting to make a transaction on the testnet with an OP_RETURN and a
change address in it, and then make a second OP_RETURN transaction from first transaction's change address in the same block. The way my code is currently written the second transaction shouldn't rely on the first transaction being processed (it gets coins from a faucet).

Here is a simplified version of my code that maintains the problem (my "write" function is a modified version of this bitcoinjs-lib example):

var assert = require('assert'),
    bitcoin = require('bitcoinjs-lib'),
    blockchain = new (require('cb-helloblock'))('testnet'),
    dynamicKey,
    dynamicChangeKey;

connect = function (callback) {
    dynamicKey = bitcoin.ECKey.makeRandom();
    dynamicChangeKey = bitcoin.ECKey.makeRandom();

    write("Connecting to blockchain!", callback);
};

message = function (callback) {
    dynamicKey = dynamicChangeKey;
    dynamicChangeKey = bitcoin.ECKey.makeRandom();

    write("Posting to blockchain!", callback);
};

write = function (arbitraryData, callback) {
    var address = dynamicKey.pub.getAddress(bitcoin.networks.testnet).
            toString();

    blockchain.addresses.__faucetWithdraw(address, 2e4, function (err) {

        if (err) return callback(err);

        blockchain.addresses.unspents(address, function (err, unspents) {
            var tx,
                data,
                dataScript,
                unspent,
                txBuilt;

            if (err) return callback(err);

            tx = new bitcoin.TransactionBuilder();
            data = new Buffer(arbitraryData.toString());
            dataScript = bitcoin.scripts.nullDataOutput(data);
            unspent = unspents.pop();

            tx.addInput(unspent.txId, unspent.vout);
            tx.addOutput(dataScript, 1000);
            tx.addOutput(dynamicChangeKey.pub.getAddress(bitcoin.networks.
                    testnet).toString(), 1000);
            tx.sign(0, dynamicKey);
            txBuilt = tx.build();

            blockchain.transactions.propagate(txBuilt.toHex(), function (err) {

                if (err) return callback(err);

                // check that the message was propagated
                blockchain.transactions.get(txBuilt.getId(), function (err,
                        transaction) {
                    var actual,
                        dataScript2,
                        data2;

                    if (err) return callback(err);

                    actual = bitcoin.Transaction.fromHex(transaction.txHex);
                    dataScript2 = actual.outs[0].script;
                    data2 = dataScript2.chunks[1];

                    assert.deepEqual(dataScript, dataScript2);
                    assert.deepEqual(data, data2);

                    callback();
                });
            });
        });
    });
};

log = function (value) {
    console.log(value);
};

connect(message.bind(undefined, log));

When running this code the first transaction processes correctly, but the second one returns this error:

{ [AssertionError: Invalid JSend Response {"status":"fail","message":"Propagation unsuccessful","details":"TX rejected"}]
  name: 'AssertionError',
  actual: false,
  expected: true,
  operator: '==',
  message: 'Invalid JSend Response {"status":"fail","message":"Propagation unsuccessful","details":"TX rejected"}' }

If I change line 15 to read

    dynamicKey = bitcoin.ECKey.makeRandom();

instead of

    dynamicKey = dynamicChangeKey;

both transactions process correctly, so the problem is definitely in my use of the change key as the next transaction key.

Does anybody know where I'm messing up?


texts: A life-cycle of a transaction - correct?

texts:
Newbie alert ! Please let me know if this is not the right forum.

So I have spent time reading up on Bitcoin. I think, I understand now; but, would love to have it confirmed.

To start with, we have a transaction, t1 as below.

t1 : {a1, 50.00 BTC, a2}

Where,
t1 is the transaction that goes to the block-chain (ledger) for confirmation.
a1 is the input, for example, Mt Gox from whom 50.00 BTC were purchased.
a2 is the output address who purchased the bitcoins from Mt Gox.

After t1 is confirmed, the unspent amount of a2 is 50.00 BTC.

Let us say, a2 wants to send 40.00 BTC to a3 for some service. Then, a new transaction t2 is created as below.

t2 : {a1, 40.00 BTC, a3}

As before, t2 goes to block-chain awaiting confirmation. The input to t2 is a1, amount 40.00 BTC and the addressee (or recipient) is a3.

Are the following correct ?

t2 has input address as a1 as described here - What does a transaction look like?
Because t2 does not mention a2, the anonymity of a2 is preserved.
t2 is confirmed because unspent balance of a2 at this point is 50.00 BTC. (Not sure how, but sounds like it.)
After t2 is confirmed, unspent balance of a2 is 10.00 BTC.

For reference, I used the following.

t1 : eac977ae6ee885b62c4756230f6bdd27ccfa7de215836e6f5fc379c66f4c6a81
a1 : 1LNWw6yCxkUmkhArb2Nf2MPw6vG7u5WG7q
a2 : 16fKtcRS2P57pH6dF5stJ4wF1SC4SzaMJK

and,

t2 : c8a8db01733a4300ad14e1fd78ff776ec21260e7081dd48c7b2f5ad1a9a1da46
a3 : 1Cmerw473xaaNpR6T9Lo5DA6d99uXLe3gc


texts: Where do the majority of Bitcoin transactions take place?

texts:
I'm new to Bitcoin and am trying to wrap my head around where and when bitcoins are used.  I understand that Bitcoin is accepted by a lot of legitimate websites (now reddit, wordpress, etc) for digital goods or services and there are also online market places that sell physical goods.  There also seems to be a lot of illicit activity transacted in Bitcoins since it is (fairly) anonymous.

My questions are basically:

What types of things is bitcoin buying and for what percentage of the total transaction volume are these things responsible?
How much of the transaction volume is responsible for physical or digital goods as opposed to just bitcoin trading?
Are these markets sustainable or are they likely to disappear (i.e. the illicit activity)?


texts:
I recall accepting bitcoin payment several years ago when the concept was fairly new. My trouble is, I don’t know what happened to the bitcoin after the receipt. What methods are available to search for “lost or abandoned “ bitcoin?
Thanks in advance
Becky


texts: How does the BTC protocol guarantee that a "main" blockchain emerges?

texts:
I'm reading up on the bitcoin/blockchain technology.
Usually, the part about proof of work and how to create a block is well explained.
However, what is never explained is how/why the communication of blocks over the network allows for a 'blockchain' to converge.
Let me explain:
what if two miners create a new block at the same time, and broadcast it at the same time ? Roughly 50% of the nodes would have each one a new (different) block, and build on it. Now, imagine this happens again etc. Then, there is not a single blockchain that is worked on, as now miners all work on several forks. The bitcoin proposal addresses this by saying that the longest chain must be used but:

at a given time there could be two forked chains with the same size, and growing roughly at the same pace
knowing which chain is the longest requires to "backtrack" possibly to the beginning, which means that no transaction on any chain can be "validated" as we are not sure to be on the correct chain

Are these issues addressed by the bitcoin protocol? Basically, it seems that there is no proof that adding blocks in a distributed fashion over the network converges cleanly into a single chain.


texts:
https://github.com/blockchain-etl/bitcoin-etl#schema
I found a library to parse the block data in json format. I want to parse that json and put it into a db to then use that for calculating balances. Is there any smart approach you can recommend me? Im talking about the db tables and maybe if this makes sense? I dont know what the wait times are for queries when it has to check millions of lines


texts: How can I know the time it takes to generate an X letters vanity address given an Y hash rate / cpu power ? Is there any online calculator for this ?


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I've seen how nodes gather network time data, but how is it enforced in the blockchain?

Are all of the timestamps digitally signed and included in the block as proof?


texts: How to create a Bitcoin Transaction With Protocoin

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Please how do I create a btc transaction and broadcast it with protocoin library? I want to create a transaction that will relay to the node without validating inputs and outputs. Of course I know the transaction will not get confirmed. I just want it to be broadcasted for a while.
Does anyone know any way I can use to do this? If there are other simpler methods to do this, I would also appreciate that.


texts: Share the same private key on two ledger devices

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I have 2 ledger device.

Let's suppose one for me and one for my wife.

We want to share the same bitcoin account.

Is it a good practice to setup the first ledger and then restore the keywords on the second ledger (while the first is still working) ?

Thanks


texts: How can I copy an address (with the private key) using JSON-RPC?

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I need to be able to create an address in 2 different Bitcoin-qt instances (actually 2 different PCs).

I can create it using "getnewaddress" on the first one but how can I import it to the second one with the private key?

Thank you!


texts: How can a single person operation keep a collection of online wallets secure?

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While this question is similar to others about securing wallets, I think it merits a question of it's own.

One thing that has dissuaded me in the past from running an online wallet service of some kind is the worry that I could be compromised (rubber hose, extortion, intimidation etc) and by extension permit full access to a large collection of bitcoins that I don't own. If I'm running an operation with potentially millions of dollars worth of bitcoins and my contact details become known (not that hard to find really) then I'm naturally a risk to my clients.

I've heard of multi-key encryption so that no one person has complete access (client PIN etc), but I'm not sure if that would solve the problem.

So my question becomes how can a single person operation ensure that they are unable to compromise the wallets under their care? Ideally the answer would not require any technical knowledge on behalf of the client beyond a passphrase.

(If such an approach became commonplace then it could act as a deterrent because attackers would simply see that the website uses that approach and slink away.)


texts: Expectancy of payout from bancrupcty claim mtgox

texts: Now it is possible to file a proof of claim regarding the mtgox bancruptcy. What is the most likely outcome of this claim? What is the expectancy one can have as a former mtgox user on this claim?


texts: Why does blockchain.info report "Estimated Confirmation time" not as 10 minutes?

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Currently, it is a timer which counts down from 10 minutes starting when the transaction is first seen. When the timer reaches 0 minutes, it switches to "Unknown / Never."

It is my understanding that finding blocks (and confirming transactions) is a Poisson process, hence the correct value should be a constant "10 minutes" and then "Confirmed!"

Is my understanding wrong?


texts: getting the unspent bitcoins based on bitcoin address

texts: im new to bitcoin and want to find out which is the best API or way for getting the bitcoin balance of a bitcoin address for any bitcoin address in C#