texts: Checking the Merkle Root for Block #100000

texts:
The below text is copied from the Bitcoin Developer Reference at bitcoin.org:

  If a block has three or more transactions, intermediate merkle tree rows are formed. The TXIDs are placed in order and paired, starting
  with the coinbase transaction’s TXID. Each pair is concatenated
  together as 64 raw bytes and SHA256(SHA256()) hashed to form a second
  row of hashes. If there are an odd (non-even) number of TXIDs, the
  last TXID is concatenated with a copy of itself and hashed. If there
  are more than two hashes in the second row, the process is repeated to
  create a third row (and, if necessary, repeated further to create
  additional rows). Once a row is obtained with only two hashes, those
  hashes are concatenated and hashed to produce the merkle root.

I'm trying to use this logic to recreate the merkle root for block #100000.  There are 4 transactions in this block.  I start by copying the transaction hash for the coinbase transaction and the one following back-to-back into a Sha256 calculator to get the hash.  Then I hash that hash one more time: Sha256(sha256()).  I repeat that procedure one more time with the second two transactions in the block.  Finally, I repeat the procedure again using the resulting hashes to obtain the Merkle Root.  Unfortunately, this doesn't tie to the Merkle Root shown in the block header at blockchain.info.

Can someone explain where I went wrong?

Thanks.


texts: How to create a transaction with a custom script?

texts:
Is there a step-by-step tutorial or any documentation covering how to create a transaction that is not a standard OP_DUP OP_HASH160 <pubKeyHash> OP_EQUALVERIFY OP_CHECKSIG?

It seems very odd that there is absolutely no documentation or information covering how to create a transaction like this, when it is one of Bitcoin's greatest advantages.

Maybe a link to some open-source software which creates custom script transactions would be helpful. I don't know of any that exist off hand though.


texts: What are the problems with naive pool sharing mechanisms?

texts: @David's comment on this answer suggests that naive approaches to mining pool management don't work. What attacks are possible on such naive approaches, such as every miner gets a share proportional to his work?


texts: Unable to use `blocks` and `chainstate` from external drive

texts:
I want to use data directory from a different location (external SSD) on a Windows machine. When I save the path for it in bitcoin.conf it still uses old data directory. How can I use datadir in bitcoin.conf?
bitcoin.conf file:

datadir=F:\bitcoin-mainnet

debug.log logs:

2021-03-05T01:34:22Z Config file arg: datadir="F:\\bitcoin-mainnet"

It still uses old data directory which doesn't have data for a synced full node (mainnet):


texts: Understanding IP address tracing via Bitcoin Transaction

texts:
I recently met a person who helped police track the IP address of a Bitcoin transaction. I wanted to learn more about it but he didn't have time to discuss about this topic in the meet.

I am curious in understanding how cryptocurrency transactions can lead to trace back of the IP address from which the transaction originated.

How does this stuff work?

EDIT

IP address is bold because I do not mean wallet transaction address.

I know originating wallet address can be traced back with blockchain.


texts: Does Ripple give an advantage to early adopters?

texts:
I really believed in the idea behind Bitcoins from the start, and because I was an early adopter, I made some nice profit.

Now I forecast a big future for Ripple too, but I don't see many ways to turn this into profit. I can start hoarding loads of XRP, but it doesn't seem likely they will become valuable in the future, because as soon as they do, transaction fees will be lowered. Another option is to start a new gateway, and because they're pretty scarce now, it may become one of the popular ones in the future.

Is there any other way I can profit as an early adopter?


texts: How can I import an address or public key into my wallet.dat file?

texts:
I have a wallet.dat with Bitcoin Address: 15iRTcgqBk1QNtr2gKkq2dUsm5nN25dSeN

I want to delete this Bitcoin Address: 15iRTcgqBk1QNtr2gKkq2dUsm5nN25dSeN and add another Bitcoin Address

How can I add another Bitcoin Address to this wallet.dat if I know its public key, but I don’t know the private key of this Bitcoin Address?


texts: If I want to sell bitcoins, assuming I was successful in either buying them or selling a service or a product and accepting bitcoins instead of normal cash. How can I convert the bitcoins back to cash ?


texts: Does port 8333 need to be opened as TCP_OUT or TCP_IN?

texts: Does port 8333 need to be listed in TCP_OUT in a firewall or in TCP_IN as well?


texts: How to install specific version of bitcoind

texts:
How do I install a specific version of bitcoind?

I want to install bitcoind version 0.12.1 in my system.

How can I do that?

I am trying to use bitcore's Insight Explorer in my project.  It uses version bitcoind v0.12 to query all those things that are shown in the UI... I have tried to run this with v0.14 but Insight UI crashes.


texts:
I've read that public keys that bitcoin uses have 130 characters (65 bytes), but on the page: http://blockexplorer.com/tx/7e9bf03454b9ff80974d39d02a8088154e60ee65726e239f70341366d1a1ccf7
I've found a public key: 30440220fe5322474a08626beac8fd44b9854fa3af52c14848993a9216b18b29793539f40220dd66a46dc1daa3d0d33fae22b7cc8ee3c753b062cc2e1a3be76183ee1f9dbbcb01 (140 characters), in addition the public key doesn't start with '04'.
There are a lot of keys with 140 characters. Is https://en.bitcoin.it/wiki/Technical_background_of_Bitcoin_addresses wrong or have I missed something?


texts: If it does not get any confirmations, will it come back to my wallet so I can fix the fee?


texts: How to keep Bitcions when reinstalling OS from fresh

texts: I have the official Bitcoin wallet and I would like to do a fresh install of everything on the computer. How can I save my Bitcoins (and hopefully block chain)?


texts: Are channel ids inherently linked to node ids in the Lightning protocol?

texts: I'm wondering if it is possible to shut down my node, change my node id, but persist my channels in the Lightning protocol. Is there an inherent limitation to the protocol that prevents this from happening? From looking from BOLT2 it seems like there isn't?


texts:
What reference implementations of Bitcoin are most suitable for backing a front end service on to with a high user load?

Something that can be put onto our own AWS or Google Cloud hardware and support being scaled up to support high demand. The front end site will allow people to have their own wallet to pay others for work or product discounts or receive funds for those same things.

One options seems to be Bitcore which has come along way since I last used it. It is Node.JS which can be put on AWS Elastic Beanstalk and it uses MongoDB which can also be scaled on AWS. Are there others and please let me know if I'm wrong about Bitcore before I get too entrenched.


texts: How can I get all the Bitcoin transactions data since its inception?

texts: If I want to get all the Bitcoin transactions since it started, how do I go about doing this? Is it possible to get all that data from bitcoind database?


texts: How are scriptless scripts and taproot different?

texts: I recently read Aaron van Wirdum's layman explanation of both scriptless scripts and taproot. I gather that both utilize the aggregation of Schnorr signatures to hide complex scripts (smart contracts) in a normal-looking transaction. What are the finer details that sets the two schemes apart?


texts: Implications of transfering to different blockchain addresses that belongs to same person with same wallet

texts: Can you send from one blockchain wallet (mine) to different addresses of mine? And what are the implications?


texts: How can you create a transaction with multiple inputs from the Blockcypher API?

texts: For example, I have two addresses and each of them has received 1 BTC. Now, I want to transfer 1.5 BTC to another address. How can I achieve this using the Blockcypher create transaction API?


texts: Does running a full node make rpc calls faster?

texts:
Hello I am running a pruning node on my VPS, and some of the RPC calls such as get balance take minutes to load. I need to check the balance every time the users access the website. I was wondering if running a full node would make these RPC calls faster.

The time command shows that bitcoin-cli is taking long due to I/O operations. What could I do?

~$time bitcoin-cli getbalance profit
0.00000000

real    6m16.762s
user    0m0.000s
sys     0m0.000s


texts: Can I program OP_CHECKLOCKTIMEVERIFY to trigger based on external verifiable events?

texts:
Can OP_CHECKLOCKTIMEVERIFY and multi-sig be used to trigger a transaction based on external verifiable events?

Some potential uses I have in mind:

Death
College graduation of a child or grandchild
Issuance of building permits
Yearly net company profits exceeding a certain threshold
Deposit refund after verification that vacation rental property is undamaged


texts: How is it possible that transactions can be added to a block currently being mined?

texts:
It seems counter-intuitive that the current block can be hashed and transactions can be added to it, however that is what this thread indicates.

Can someone help me connect the dots (not necessarily regarding that linked network attack) and understand how something under active computation can have its underlying data (list of transactions) changed?

In other words, if a tx isn't "bound" to a block via hashing, how do they relate to each other?


texts: What is the best method for creating a paper wallet?

texts: I am looking to move some of my bitcoins from cold storage to a paper wallet.  I have heard that metal stamping is one of the better long term strategies since paper can burn or fade.  Any other suggestions?  Thanks in advance - Kristine


texts: Does the dogecoin daemon support ZeroMQ feature like the bitcoin deamon?

texts:
I am using Dogecoin v1.10.0 and I am wondering if the daemon, dogecoind, supports publishing transactions and blocks via ZeroMQ like bitcoind does? My dogecoin.conf looks like the following.

rpcpassword=test
rpcbind=10.211.55.111
rpcallowip=10.211.55.1/24
rpcallowip=10.211.55.111/24
zmqpubhashtx=tcp://10.211.55.111:38323
zmqpubhashblock=tcp://10.211.55.111:38323
zmqpubrawblock=tcp://10.211.55.111:38323
zmqpubrawtx=tcp://10.211.55.111:38323
txindex=1

I start dogecoind like the following /usr/local/bin/dogecoind -datadir=/etc/data/dogecoin/data -daemon

However, when I see which ports are listening netstat -peanut | grep dogecoind I only see the following.

tcp        0      0 0.0.0.0:22556               0.0.0.0:*                   LISTEN      0          34038      8425/dogecoind
tcp        0      0 10.211.55.111:22555         0.0.0.0:*                   LISTEN      0          34036      8425/dogecoind
tcp        0      0 :::22556                    :::*                        LISTEN      0          34037      8425/dogecoind

As I understand port 22555 is the default RPC port, and 22556 is the port connected to by remote peers for transaction/block propagation.


texts: difference between signing a message and signing a p2sh

texts: can i use the sign message function to sign the serialized hex for a p2sh transaction? Are the ecdsa functions used the same or are they different? It looks like the output is in a different format than a traditional tx signature? How can one use this function to sign?


texts: Retrieve number of OP-RETURN transaction

texts:
Is there a possible way to extract the bitcoin transaction protocoll with Python and extract specifically OP RETURN transaction?
I want to plot the number of those over the course of time to derive some statistics from it.

Best regards
Nils


texts: How to copy wallet.dat from v0.10.2.0 to v0.11.0.

texts:
I am trying to import the balance from the older version to the newer one. I deleted the wallet.dat from the newer one and copied the older one into its place. However, the wallet will not start with the old wallet.dat. I get a small "error" msg box. When I click "ok" qt closes down.

Are the two wallets incompatible? If so, is there another way to import my balance to the new wallet?

Thanks


texts: Can someone explain the pitfalls of NXT Proof of Stake's potential issue of "nothing at stake"?

texts: Many people talk about NXT Proof of Stake (PoS) being insecure due to the "nothing at stake" problem. I read up some posts about nothing at stake, but I still do not understand how it works. Can someone explain how the "nothing at stake" works in laymen terms and how it affects Proof of Stake coins like NXT?


texts: Is a P2WPKH address synonymous with a Bech32 address?

texts:
BIP142 when encoding a segwit P2WPKH address is using a base58 address format (address p2xtZoXeX5X8BP8JfFhQK2nD3emtjch7UeFm in the example).

I understand that BIP142 predates BIP173 but are P2WPKH and Bech32 synonyms now? Is there such a thing as Base58 P2WPKH address?


texts:
I haven't yet traded any cryptocurrencies. I'm planning to buy BTC through Coinbase then exchange BTC for a small amount of XRP.

The main reasons for going with Coinbase is it's safe, well regulated and I'll always want an account there. For XRP, I'll use changelly.com since they are popular, have low fees, and haven't been hacked (yet).

A big concern is safety. Coinbase probably has a good wallet but I'd like to use a hardware wallet since I'll be using other exchanges for various alt coins not offered on Coinbase. I don't really trust other exchanges and hence the hardware wallet.

Is a hardware wallet the safest option in this case? Are there any issues using it at Coinbase and Changelly?

Do I still need to setup wallets at exchanges I'm using?

When using a hardware wallet, from what I understand, you plug it into your computer via USB and do whatever transaction at whatever exchange. Once complete, you unplug it. From this, it basically can't ever get hacked?


texts: How do "Pay to Script Hash" transactions work?

texts:
BIP16 gives the following example to explain "Pay to Script Hash":

scriptSig:    [signature] {[pubkey] OP_CHECKSIG}
scriptPubKey: OP_HASH160 [20-byte-hash of {[pubkey] OP_CHECKSIG} ] OP_EQUAL

But I don't get what's happening here. I've tried executing the script on paper (and assumed the parts in squared/curly brackets are treated as constants):

[signature] and {[pubkey] OP_CHECKSIG} are pushed onto the stack
OP_HASH160 hashes {[pubkey] OP_CHECKSIG}
The same hash comes from the scriptPubKey onto the stack
Consequently OP_EQUAL gives True
The [signature] is not checked at all!

If the {[pubkey] OP_CHECKSIG} is executed, the scriptSig would only give True, which makes even less sense.

To frame a clear question: How do "Pay to Script Hash" scripts work, especially this example case?


texts:
I do not have trust in random exchanges.

I'm looking for regulated exchange so I'm less likely to lose my BTC.

What are the regulated exchanges out there?

Some hints:

https://techcrunch.com/2015/01/25/coinbase-us-bitcoin-exchange/
What changed about coinbase.com to make it a "regulated exchange"?


texts: What happens when a transaction is included in more than one block?

texts: What happens when two miners include same or set of transaction in their block, mine it and then broadcast it at same time? Can the transaction be included in two separate block like this OR a fork happens?


texts: Proof of work: average number of tries to create a block

texts:
First, I'm sorry if I'm asking a stupid question. I'm just trying to understand bitcoin. I'm reading the Ethereum white paper, and I couldn't understand this sentence about proof of work:

  At the current target of ~2^187, the network must make an average of
  ~2^69 tries before a valid block is found

My question: how the 2^69 number of tries is computed?

Updated:

My question: why 2^69 instead of 2^70 or 2^169?


texts: Whenever we use an online mining calculator, do these calculator estimate a 100% blocks finding? Shouldn't they be subject to the pool efficiency and how many blocks are found? I mean, if my pool only catches 50% of total blocks my mining earnings are cut in half. Is this right?


texts: To test if my wallet.dat encryption password is correct, MUST I spend coins?

texts:
When a Bitcoin Core wallet is encrypted, you (apparently) have to enter the decryption passphrase only when trying to spend coins. You still get to "use" the wallet as in seeing all the transactions and labels.
I'm worried that my saved passphrase (partially on the computer/paper and in my head) is not correct. But to test this, I would have to spend coins... or do I?
I suspect that you'll say: "Use the change passphrase feature!"
But that would just put me again in the same situation. Of course, I had to repeat the passphrase (two times in total) to enter it in the first place, and this would be done again. So I'd again be paranoid that my keyboard has a faulty key or something like that.
Is there some way to "test unlock" a wallet without actually spending any money?


texts: What is a decent value for Time Lock Delta on a lightning network node?

texts: Looking at the settings of some nodes on 1ml.com, I noticed the Time Lock Delta variable could vary a lot. How does it affect a node, and what is considered to be a decent value for it?


texts: In a blockchain, considering that each block stores the hash of the previous block, the hash of the last block is not stored anywhere. How is this block tamperproof?


texts: Is normal ECDSA verification slower than a verification method based on Public Key Recovery?

texts:
Background info:

This post on the Cryptography stack exchange shows how to almost uniquely recover the public key from the signature, hash of the signed data, and knowledge of the curve: https://crypto.stackexchange.com/questions/18105/how-does-recovering-the-public-key-from-an-ecdsa-signature-work. I believe it basically produces two public keys for which the signature given will validate for the hash.

Main Question:

Given a public key Q, a signature S, and the hash of some data H, it seems that there are two ways that we can verify that this triple is valid.

We can run the usual ECDSA verification routine, which is somewhat time intensive.
We can run public key recovery with (S, H, Curve) and verify that one of the 2 possible returned public keys (4, really, since each can be either compressed/decompressed) is the point Q. I am not sure if this is more/less time intensive.

So,

Is verification through public key recovery more or less time intensive than the usual ECDSA verification?
If less, then couldn't bitcoin do all it's ECDSA verification through public key recovery and save time? Granted, checking a pubkey-hash would involve taking each candidate public key, OP_HASH160 hashing it and seeing if it comes out to the right 20 bytes of the address. And if none of the 4 possibilities hash to the correct value, then the signature verification failed.

My only reason for asking this is that ECDSA verification is slow, and I read somewhere that public key recovery is very fast, so just wanted to see if anyone has any insight into this.


texts: What does "Uneconomical UTXO requested" mean?

texts:
I'm using the btc.com wallet and I want send 0.001 btc to another address but I'm facing this error: Uneconomical UTXO requested [type: 1 (limit 6831), txOut.val: 5897, required: 98140]
What does it mean? And how can I resolve it?


texts: How can I transfer the last little bit from my Bitcoin Core wallet to Armory?

texts:
I'm moving my bitcoins to Armory because its deterministic wallets are SO much better for keeping good backups. But bitcoin core didn't make it easy for me to sent all my money - if I specified all of it, it complained that my transaction + the 0.0001 fee I specified was more than my balance (makes sense). But when I specified my balance minus 0.0001, it complained that my transaction + the fee of 0.0002 (which was twice what I specified) was more than my balance. Wtf right?

So I played around with it til I sent all but a few cents of my balance. So I have 0.000047 BTC left, which isn't a big deal, but it feels wrong to just leave it there to rot. How can i recover those micro bitcoins without losing the whole transaction to a fee?


texts: What does change address mean inside Electrum wallet?

texts: I am bit confused with the change label that is inside Electrum Wallet . Can I receive bitcoin if i give this address which are under change label? What is the difference between Receiving and Change Label Address?


texts: Json-rpc fails with "No connection could be made because the target machine actively refused it"

texts:
Playing around with litecoin json-rpc running on windows (the API is the same as bitcoin, so I am using bitcoin's references).

My litecoin.conf has the following data:

rpcuser=user
rpcpassword=pass
txindex=1

Based on the documentation I started the core client as .\litecoind.exe -server, and it looks like it works just fine because I can run various commands from another window (.\litecoin-cli.exe getblockcount and many other work as expected).

Now I wanted to make some json-rpc calls and I tried Go's library which bitcoin's developers recommend. I used the example from that library's github and the only modifications which I introduced were my user and pass in the definition of the ConnConfig.

The code fails during the execution of client.GetBlockCount() with an error:

  Post http://localhost:8332: dial tcp [::1]:8332: connectex: No
  connection could be made because the target machine actively refused
  it.

I think that the problem is with json-rpc server but I have no idea how to verify that it works properly. Any idea how to fix it?


texts:
i'm still running the qt 0.63, wich has a problem syncing to the network. It gains about 1% a day.. bitcoins that have been sent my way cannot yet be seen in my account. is it safe to make a back-up now and uninstall the qt client, and then reinstalling a newer version or a different wallet? Can i just copy-paste my wallet.dat after that?
thanks


texts: Passing a JSON argument to bitcoind in Windows command prompt

texts:
I've been trying to use sendmany on my local installation of Bitcoin-qt (version 0.7.0) from the Windows command prompt. I've seen examples but when I try them all I get is a JSON parsing error. I figure that on Windows the input needs to be escaped in a different way than on Linux.

How do I pass a JSON argument to bitcoind from the Windows command prompt?


texts: How does transaction confirmation work through mining process?

texts: Hi i am just a newbie in this thing but there is something i can not understand if blockchain keeps every transaction in it and creating a new block to blockchain takes so much time then doesn't it supposed take long time to confirm a transaction that is sent from A to B?


texts: PLEASE help me get armoury to online on my mac?

texts:
Macos 10.11.6 El Capitan
Armoury 0.93.3
BitcoinQT v0.17.1
I have to use those software versions to get them to open in OS10.11
I cannot get armoury to go online. PLEASE HELP ME.
Both apps open separately.
I type this '/Applications/Armory.app/Contents/MacOS/Armory' into terminal and got this.
(ERROR) ArmoryQt.py:7074 - Socket already in use.  Sending CLI args to existing proc.
(ERROR) ArmoryQt.py:7078 - Exiting...
I'm not sure if this is the only issue or how to fix it?


texts: Blockchain: How do nodes know what Data is correct from Consensus process?

texts:
How do nodes know what data is correct from consensus?

What about if two nodes execute two different consensus with 2 different Valid blocks with the same height at the same time, can that happen?

I’m talking about Blockchain in general, not bitcoin, not mining.

Not bitcoin related, Not mining related


texts: How multi-signature wallets comunicate with each other?

texts:
I wonder how multi-signature wallets communicate with each other?

My favorite wallet is copay. How do they communicate with each other before payment is done? How is privacy handled between each multi-sig device?


texts: I have over 10,000 shares accepted. How can I find out how much bitcoin that is?

texts: I have over 10,000 shares accepted.  How does that translate to bitcoin?  How much bitcoin is 10,000 shares?  It says it will transfer to my wallet when I get .01 bitcoin.  But so far, nothing in my wallet.


texts: Wrong Adress Blocking System for Transfers

texts:
I want to withdraw my BCH (BCC) in Bitfinex to transfer to Bittrex. I selected BTC to deposit address. In conclusion I sent wrong currency address. There is no system to warn us "You input wrong currency address".

Can anyone guide me to recovering the coins?


texts:
Many years ago I looked into gifting 1BTC to each of my God sons, who had just been born. That gift would be worth a fair bit today, but I didn't do it because I couldn't figure it out.
How could I do this today? Remember, the recipient is 0 years old and can't upload their passport :)


texts: In Multibit HD, is there a way to see all of my receiving addresses?

texts:
I understand that if I request a payment and delete the request, I still own the address and will receive Bitcoins that were sent to it.  However, I find it very uncomfortable to just "assume" that I own an address.  I would much prefer if I could look somewhere and see a list of the addresses that are mine.

Is there a place I can see all of my addresses?  What are the conditions under which I will no longer own an address?


texts: In macOS build instructions for Bitcoin Core, why do they recommend creating RPC configuration file?

texts:
In this file

https://github.com/bitcoin/bitcoin/blob/master/doc/build-osx.md

  Before running, it's recommended you create an RPC configuration file.

Why?


texts: Deciphering cgminer interface in terminal

texts:
Am brand new to mining, and wanted to download an OSX miner just to experience (fully realizing that it would not be profitable). With cgminer connected to a mining pool, I see the following interface...

... Can someone help me understand what each of the indicators mean (A, R, HW, WU, ST, SS, NB, LW, GF, RF)?


texts: How do I send money from imported keys to my localbitcoin wallet?

texts:
Okay, I imported keys from my desktop to MultiBit, it took a while, now I have got a file on my desktop, when I open it with notepad there is like: "receive, *walletadress", receive walletadress" etc.

Now, could you please tell me how to send money from these wallets to my current main wallet on localbitcoins?


texts: Why do I have more unconfirmed tx than getmempool info reports?

texts:
I presently have 39 unconfirmed tx that I've sent according to my local bitcoind:

$ bitcoin-cli listunspent 0 0  | grep account | wc -l
39

(note: the above command gives the correct answer because the tx were sent to the same bitcoind wallet.)

I made a script to watch the mempool size via getmempoolinfo and record the high and low amounts.  Here is output:

  size: 9359
  bytes: 9165998

  size_low: 16
  size_low_when: 2017-08-22T14:29:49-07:00

  size_hi: 71196
  size_hi_when: 2017-08-22T13:46:14-07:00

  bytes_low: 3063
  bytes_low_when: 2017-08-22T14:29:49-07:00

  bytes_hi: 53361196
  bytes_hi_when: 2017-08-22T13:46:14-07:00

  last_block_found: 2017-08-23T01:13:02-07:00

Notice that the smallest size that has been seen is 16.  This comes from the "size" output of getmempool info, which according to the help docs indicates the number of tx in the mempool.

Seemingly then, getmempoolinfo was (for a brief time at least) reporting fewer tx in the mempool than the number of my own sent tx that are still unconfirmed.

How is that possible?   Is this a bitcoind bug, or am I misunderstanding something?

$ bitcoin-cli help getmempoolinfo
getmempoolinfo

Returns details on the active state of the TX memory pool.

Result:
{
  "size": xxxxx                (numeric) Current tx count
  "bytes": xxxxx               (numeric) Sum of all tx sizes
}


texts: Do confidential transactions produce an UTXO

texts:
There must be magical cryptographic reason why CT doesn't create an UTXO.
If it did make an UTXO, it'd be trivial to calculate the input + output right?


texts:
I am attempting to run a full bitcoin-core (v0.13.1) node over the Tor network for the first time. I have set up my /etc/tor/torrc file with the following two lines:

HiddenServiceDir /var/lib/tor/bitcoin_service/
HiddenServicePort 8333 127.0.0.1:8333

I have set up a file ~/.bitseed/bitseed.conf with (not sure this is required)

onion=1

I retrieved my onion address from /var/lib/tor/bitcoin-service/hostname allowing me to set up ~/.bitcoin/bitcoin.conf with settings such as:

onlynet=onion
onion=127.0.0.1:9050
listen=1
bind=127.0.0.1:8333
externalip=<my-onion-address>
seednode=wxvp2d4rspn7tqyu.onion
seednode=bk5ejfe56xakvtkk.onion
seednode=bpdlwholl7rnkrkw.onion
seednode=hhiv5pnxenvbf4am.onion
seednode=4iuf2zac6aq3ndrb.onion
seednode=nkf5e6b7pl4jfd4a.onion
seednode=xqzfakpeuvrobvpj.onion
seednode=tsyvzsqwa2kkf6b2.onion
banscore=10000
bantime=11

It seems to be working as I can see my mempool growing from the debug file, and I have one inbound connection. But my connection count is very small (2 or 3). Is there anything else I need to do? In particular, I wanted to confirm that I have no need to set up my firewall ufw to accept connections on port 8333 (or 9050) in order to achieve inbound connections, and I have no need to redirect port 8333 or 9050 from my router to the fixed local ip address of my machine (setting up ufw to allow 8833 and redirecting port 8333 from router would be required if I was running a normal node).

EDIT: 9 connections of which one inbound, but this single inbound connection is myself. So the question really is: How do I allow inbound connections?

EDIT2: I am now of the opinion that this setting is correct. I was wrong to think a prior inbound connection was to 'myself', after 24 hours I have seen a peek of 4 inbound connections. I can confirm there is no need to tweak ufw or change any of your router settings (the tor protocol is not affected by either of these), and this seems to be working having tor on top of a VPN connection (bitmask). Hence I have no more questions but happy to stand corrected if any of the above is wrong.


texts: If I sent bitcoins to someone, but then want to cancel this transaction after it was already made (like a chargeback on a credit card), is this possible with Bitcoin?


texts: Is it possible to create a unified client that manages multiple cryptocurrencies? Does such a client already exist?


texts: how to generate bitcoin adddres using seed?

texts:
Hi i am new to bitcoin all i want to know is how to generate address using mnemonic seed?

let testnet =Bitcoin.networks.testnet;
let keypair =Bitcoin.ECPair.makeRandom({network:testnet});
let address=keypair.getAddress();
let privateKey=keypair.toWIF();
res.json("Public Address  "+ address+ "  "+privateKey)


texts: Does blockchain without currency make any sense?

texts:
I keep reading about private companies building blockchains for stuff like supply chain management, and about the billions of dollars that are going to be invested in blockchain over the next 5 years, but there is a gap in the logic here that I don't get.
Distributed Ledger Technology is totally reliant on participation to establish the principle of Distributed Trust. If there are not enough independent actors in the network, you cannot rely on the immutability of the ledger.
In Bitcoin, the blockchain provides a way for participants to "profit", thereby pulling independent participants into the network. Participants are attracted to Bitcoin as they view it as an alternative to another currency (fiat) they perceive to be weakening in value.
Private and Consortium blockchains make no sense to me, but let's say some agency decided they wanted to seed a new public blockchain to do something like: verify that a particular coffee brand came from FairTrade sources.
How would they incentivise independent actors to verify transactions in this chain? Is it the case that they have to create a token reward, and hope over time that the token develops some minimal transactional value, and hope that early adopters make a return? Why would such actors not just participate in standard cryptocurrency blockchains?
It seems like a very hard sell, given the effort involved in running Internet connected hardware.
From where I'm sitting, its hard to see how a public blockchain can have any application beyond replacing fiat currency.
Is my understanding of this correct?


texts: Can a bitcoin wallet be restored from the files on a drive?

texts:
Hard drive crashed and requires professional recovery (likely needs newly built heads by professionals in a clean room).  I don't recall what windows desktop bitcoin wallet software I installed and used about 8 years ago.

If I can recover the data files from the bad drive, can those recovered files be used to recover the bitcoin wallet by installing the bitcoin software on a new computer and then somehow copy some data files over from the recovered drive?  If so, how would I figure out which wallet software I had and installed / used when I look at all of the professionally recovered files?

Unfortunately,  I can't find my backup seed : (


texts: How much does it effectively cost to purchase currency at an exchange?

texts: If I buy crypto-currency at, for example, Kraken, how much does it effectively cost me to buy it and move it to another wallet or exchange?


texts: Are there some reasons why maven and standard maven directory layout are not used in Ardor?


texts: I just made a huge mistake,i sent my claimed BCC from my Exodus wallet to my  BTC.com wallet .oops .Can i get them back ? The transaction has been passed OK on the block chain.


texts: Why can not use an exchange address for p2p mining?

texts:
Most p2p mines (like this one) have the following norm:

"Don't use an exchange address!"

I am mining alt cryptocurrencies but I do not have a real interest in maintaining a separate wallet for every kind of currency. Why they do not admit addresses from exchange sites?


texts: Why does each block store a Merkle root?

texts:
I understand how a Merkle root is calculated and stored in the block. But how do miners verify a transaction using the Merkle root?

Here are 18 conditions that verify a transaction. None of them uses Merkle root.


texts: I just recently installed armory an bitcoin-core. They constantly are using 100's of GB's of internet. Its getting annoying, because i cant really use the bitcoin if armory is constantly offline. I got an online wallet in matter of seconds, and changed all my miners to go to that instead. How would i stop bitcoin and armory from still downloading, because i want to send all my bitcoin to my online wallet.


texts: Can someone explain how the Bitcoin Blockchain works?

texts:
I'm trying to figure out how the blockchain works and how to read it via blockchain.info website. Is there a laymen way of explaining how the block chain works and how to read the blockchain to trace transactions?

What I know so far is:
the blockchain is just a public ledger of transactions on the bitcoin network.


texts: RPC Wallet API methods "getblockhashes" was removed?

texts:
I'm testing RPC wallet API methods of Bitcoin 0.13.2, and I realized the method getblockhashes (method returns an array of block hashes for a specified block range ex: between two timestamp) cannot be called, the API returns "Method not found", so is it removed? I'm locking for a method that works like this method.
Thanks.


texts: How do you determine 'magic byte' or version for alt coins?

texts: I'm looking at creating a deterministic wallet for some of the less popular altcoins. Bitcoin has a magic byte of '0488b21e' and litecoin '019da462'. How are these determined or calculated? Also how would I generate these values for other altcoins?


texts: How does the difficulty target affect the time to complete the block?

texts:
So, I'm currently doing a personal project where I'm creating my own crypto blockchain (just for fun). I'm currently coding the Difficulty Target part of the Blockchain, but I'm not entirely sure how the difficulty part affects the process for completing the block? I know that with Bitcoin, the difficulty adjusts every 2016 blocks based on how long it took to complete the 2016 blocks, but what is the difficulty applied to and how does it make subsequent blocks harder/easier to complete?
Thanks.


texts: Sending from address to address in bitcoind

texts:
I'm programming the back-end for an ecommerce solution, Bitcoind API gives me one way of sending money to a bitcoin address: sendfrom <fromaccount> <tobitcoinaddress> <amount>

If I understood well, this will transfer money from one account to an address, but I don't see any way of sending from address to address. I didn't implemented accounts on my backend system, and don't want to do it as it's an aditional layer of complexity that I don't want to deal with right now.

So, I supose this will grab money from whatever address/addresses asociated to the account and send them to the bitcoin address provided. Any way of doing what I want to do?


texts: Can I run bitcoind without downloading new blocks?

texts: I want to run bitcoind to interact with the daemon, but having bitcoin download new blocks and verify them is taking a toll on my CPU. I do not want the latest data - I just want the daemon to be running. Is there a way to prevent bitcoin from downloading new data?


texts: How can I use multisig / split keys using My Wallet?

texts:
I was sure that My Wallet supported multisig, but I can't seem to find it now.

How can three users of My Wallet create an address that is only spendable if at least two of them cooperate? Or is this not implemented yet? If so, when is it due?


texts: What wallets can be used to double spend (low tx fee workaround)?

texts:
I've got myself in a bit of a pickle. I withdrew some Bitcoin from a service last month, however they sent it with a really low fee (40 sat/byte), so it is still pending and is unconfirmed. I understand Child Pays for Parent, but the inputs of this transaction, around five levels deep, are also unconfirmed. I asked them to resend the transactions with a higher fee, but that might take a while.

Today I sent a transaction from Blockchain info. I used a reasonable fee for today (250 sat/byte), so normally it would be confirmed within a few hours. However the transaction used the unconfirmed transaction as an input, so that transaction would need to be confirmed first, which probably isn't going to happen.

As I understand if I send a new transaction, with a higher fee, I can reuse the (confirmed) inputs and that transaction will be accepted, then the transaction with the unconfirmed input will be abandoned. I've tried using Electrum to resent the transaction with a higher fee  (and making sure it doesn't use the unconfirmed inputs), however it just says an error saying my balance is too low, as it treats the unconfirmed transaction as spent.

Are there any wallets (preferably that don't require downloading the whole blockchain) that would allow me to create a transaction to work around this?


texts: How to make ImportMulti function like ImportAddress for watch-only addresses placed into Accounts?

texts:
My question is: I want to use ImportMulti to import a long list of watch-only addresses.  However, unlike ImportAddress, I don't see any way to place these addresses into specific "accounts".  Is this even possible?

UPDATE: After more research, it seems to me that the concept of "label" is basically the same thing as "account".  Is this correct? Seems kind of confusing to me. If this is the case, then ImportMulti can work as I want, by using the "label" property.


texts: Does Merkle Tree root hash changed when miner node not found POW nonce?

texts:
In bitcoin PoW process,if miner does not found the nonce, I understand that he must
to increase nonce and rehash the entire block header again
to mine the new block.
so if nonce defined 4byte[between 0 and 2^31],
goes from 0 to 2^31 finally and even not found the target hash, does the miner rehash the Merkle Tree including coinbase transaction?
And what algorithm for miner to change coinbase transaction?


texts: I am writing transaction monitoring service but I am having some problems with listing since block hash. I have bitcoind daemon and when I execute listTransactions some transactions have same block hash so if I would try to listSinceBlock I would have problems. How this all works?


texts: Whats the difference between funding to mutisig address and general address start with '1'?

texts:
I build raw transaction: '0100000001b0e1a9cc83fbe8918a1cf20e0c72cf2fe3af252f228a3a0223943c2732f69bd8010000006b483045022100cf98600ba4f4d7bc748e36e4bb7eed48a26d7eab45bb813f65781ca7921a163702204f857a25574ba50c54373dc9fcdbba51ac1653b1007832b8314a7ccc2224d927012102534fd869124dff1cc99c430b97a5b6817b1f8343ce1e1de3ff71d4a3fc6c1592ffffffff02307500000000000017a9146cf00a2686081c15e931f7413b0f07561388c9c18764000000000000001976a914e093b1e8185d6b8136a80c8ab02e2f0bbfaf15c288ac00000000'

but it failed to boardcast , are there some difference between funding to multisig address and normal address when building raw transaction and signing transaction?

You can also find both of two kinds of address appear in my outputs, does bitcoin network support this?


texts:
Is there any way to know bitcoins wallet name using these details

pubkey publicaddress rsz signatures sha-256 ripemd160 script signature ( asm & hex )


texts:
I am ready to put some of my BTC holdings into a couple different cold storage wallets.  I went through the process already moving around a few mBits as tests, created the keys on an offline PC, sent real funds, then ran an import in bitcoin-qt, all good there!

My concern is this, If I move a few BTC into individual 1BTC wallets, do I have to worry about any Change Address issues if I simply ignore them completely for a long time?  Assuming my private keys are kept safe over time, is there any way I can lose funds this way?  I do not plan on making further deposits into any of these wallets, if my funds grow I will keep another hot wallet or setup more cold storage.  I also do not plan on withdrawing funds at any time, when I do it will be a full sweep per wallet.

Before I proceed with sending my hard earned mining BTC to each address, I want to make sure I take all the proper precautions, any help from you BTC pros is greatly appreciated.


texts: Can I run bitcoind without BerkeleyDB 4.8 installed?

texts:
I am using a CentOS server to build Bitcoin from source. After installing all of Bitcoin's dependancies on this build server, I have successfully built bitcoind and bitcoin-cli (the two binaries that I need). I then copy those binaries from the build server to the bitcoin server which of course is a fresh image of the CentOS. Now I'm wondering if I need to have BerkeleyDB 4.8 installed on the bitcoin server, or if I'm just not compiling/linking bitcoin properly.

The error as you would expect if BerkeleyDB 4.8 is not installed/linked properly:

error while loading shared libraries: libdb_cxx-4.8.so: cannot open shared object file: No such file or directory

It was my assumption that I can install dependancies on one server, link and build bitcoin on that server, and then move the binaries to a server without scary build dependancies on it to run the binary in a clean environment. Someone please shed some wisdom on my lack thereof.


texts: Is there an app where I could add my public keys for several alt-coins that I have, to see the current balances. Kind of like a multi-currency wallet/tracker, but read-only.


texts: If I've lost my wallet, but know my bitcoin receiving address, can I get my bitcoins back?

texts: Although I do have a backed up wallet file, I seem to also have a second bitcoin receiving address, which doesn't seem to correspond to it. Is there a way to recover any coins associated with that receiving address, or are the coins lost forever?


texts: What does it mean if TXID and WTXID are the same?

texts:
I'm having a tough time understanding what exactly WTXID is and what it means when WTXID and TXID are the same (and vica versa).

What I understand is that WTXID includes the witness data. Since non-segwit transactions do not have the witness segregated, their WTXID should be the same as the TXID. Is that correct?


texts:
Let say, I create wallet and have two public key and one private key.
And I remove the first public key from the wallet.
Can I restore and use my first key again? Or it's removed at all.
Sorry for the maybe a silly question I'm a newbie.


texts: It it posible, pros and cons using multiple pass phrases on same blockchain?

texts:
new to crypto, from what I can tell so far, the pass phrase is equivalent to knowing the private key. If this assumption is true -
In theory and for example, what are the pros and cons creating a new pass phrase/private key for each new $1,000 invested/earned, if possible ? (In the best case, this happens infinitely).


texts:
I was sent a discord message with an invitation to an exchange called www.doxxwallet.com. They offered me 0.21 bitcoin as a joining bonus, and I created the account and according to them do indeed have a wallet with .21 bitcoin. In order to withdraw the bitcoin, I have to transfer to the website 0.006 bitcoin and then I can withdraw the entire balance.
This sounds pretty scammy, but I wanted to see if anyone else had heard of them or had a way to verify that this website is legitimate? I have an image of the message I received below.


texts: Calculate the difficulty of Bitcoin network

texts:
Which variable among the components of the block header is computed (or rather obtained) to achieve the difficulty posed by the bitcoin network?

Nonce or Previous block hash?


texts: Are there any combination of letters that a namecoin address cannot start with?

texts:
It recently came to my attention that some Namecoin addresses might not be generated at all (see https://bitcointalk.org/index.php?topic=84569.msg1370025#msg1370025 ). Namely, there are issues with generating addresses starting with

Na, Nb, Nc, Nd, Ne, Nf, Ng, Nh, Ni, Nj, Nk, Nm, Nn, No, Np, Nq, Nr, Ns, Nt, Nu, Nv, Nw, Nx, Ny, Nz, NL, NM, NN, NP, NQ, NR, NS, NT, NU, NV, NW, NX, NY, NZ

Is there some reason behind it, or is it just some vanitygen bug?


texts: Is it Possible to put s9i software on an s9

texts: The antminer s9i achieves slightly better stats than the s9 but uses the same hardware. Is their a way to put s9i software and firmware on an s9? Also I am used to the Linux operating system and flashing images etc. Would I be able to do this myself?


texts:
Just what the title states.
I'm just a couple of days into this idle CPU utilization thing; I run a CPU miner (x-coin-minerd on a Windows 7 box).
Scrolling through the command line output I see several lines that say 'accepted' - some show a 'Yay', whilst others show a 'Booo'. Yet some 'Yay' show a lower match (70%), and some 'Boo' show a higher match (>75%).
(The previous entries were lost, but the most recent Yay/Boo visible on the command line are posted below for reference)

[2014-06-24 08:37:25] accepted: 14/15 (93.33%), 89.76 khash/s (booooo)
[2014-06-24 08:37:45] accepted: 15/16 (93.75%), 89.75 khash/s (yay!!!)

Why do I see a 'Yay' with a 70% match, and a 'Booo' with a 75% match?


texts: What legal items should I know about if I am piggy-backing off of another bitcoin exchange?

texts:
I am thinking of starting a crypto exchange in the US, and I am piggybacking off of AlphaPoint's exchange for liquidity's sake.

What legal documents should I be aware of if I am piggy-backing? FinCEN comes to mind, and I may have to reject customers from NY :(

Thanks for the help in advance, I just want to get a scope on the extreme regulation before I start


texts:
As far as I know, all bitcoin addresses start with a "1" or "3" prefix.
I've just started using electrum wallet and all the addresses it generated had a prefix of "b", or even "bc".
Is this legit or some scam, and if legit, does it have a special meaning (like segwit addresses starting with "3" prefix) and where can I read more about it?


texts: How do you know that your private key has been stolen?

texts: How do I know whether my private key has been stolen?


texts:
Assuming two blocks are published at exactly the same time, a race for the next block to be added to one of them begins, which eventually one chain will eventually win.

My question: will the shorter chain still be published? Does the network still syncronize the shorter chain, i.e. does every client contain a copy of not only the longest chain, but all (for lack of a better word)  "sidechains"?
If so, are there any conditions as to what will be syncronized beyond block validity?

Thanks in advance!


texts: Easiest way to set up non computer-literate person with Bitcoin

texts: What would be the easiest/quickest way to get somebody who isn't computer-literate set up to have the ability to transfer money to me via Bitcoin? Also, Bitcoin touts that it is anonymous. Is it any more anonymous or untraceable than a simple cash transaction?


texts: Electrum wallet giving dust error even for larger amount

texts:
I have used this wallet sever times before to send or receive. I closed, downloaded and tried again to send to multiple addresses.
Error message:
http://imgur.com/Om2Dqyi


texts:
Vertcoin comes with Adaptive-N-factor, which means the scrypt algorithm PBKDF parameter N will be changed according to the announced time table. Litecoin has N=10, while Vertcoin starts with N=11. And they claim the adaptive-N will resist the ASIC miner.

To produce an ASIC produce, it will need a huge amount of initial cost because of the prototyping (FPGA), HDL design, emulation, synthesis and layout, wafer fabrication, packing, and testing.

However, scrypt ASIC is now a real product (no matter how much it costs now). So re-target it to another new parameter should be not too difficult. I mean the whole architecture does not change (PBKDF is the same; only some parameters change, such as memory size and N), so the new ASIC development won't need to be started from the scratch up, such that cost is relative smaller than the initial product started from ground zero. Moreover, at the time of N adjustment at Jan 2016, the transistor size will be smaller and memory speed will be much higher, new technology will also enable the realization of the new ASIC miners for the new N factors.

If CPU/GPU can do the scrypt adaptive-N-factor algorithm at that time, I can say ASIC can also do that if there is a market and lots of demands. My idea is that, if vertcoin is very profitable (like or surpass BTC), Those ASIC company would also love to produce their ASIC miners with new N-factor. They could produce scrypt N=12 miner ready for the N-factor changes at Jan 2016, and announce for the pre-sale 3 or 6 months ago.

To me, adaptive-N-factor is just like one of BTC difficulty things. No one is mining BTC with miners whose hashrate is MHs or 10GHs or below, although all BTC miners are using the same proof-of-work algorithm SHA.


texts: Buy bitcoins with my regular AMEX (american express card)

texts:
I can not find any website or service to buy bitcoins with my AMEX.
www.bctquick.com does not work aymore ? (webpage inactive)

any advise ?


texts: What is the best way to test new consensus protocol?

texts:
I wanted to test a new consensus protocol. However, the bitcoin core is a large codebase (>100k lines). Is there any small codebase which is designed to test new consensus protocols and includes only essential features of a cryptocurrency?

Goal: Run a testnet with a few AWS-EC2 instances across the world for payments using UTXO model.


texts: Sent two btc transacton to payeer wallet less than the mnmum deposit,neither where credited

texts:
recently sent to my payeer wallet a 0.0002 btc transaction which is less than the 0.0005 minium btc deposit, then did a second transacton of 0.0003 btc thnking that it will sums up.
Both transaction where conrmed more than 100 times and sent to the payeer wallet adress but are not credited and payeer system refuse to credited it. Yet those btc habe been sent to as the bitc explorer show for a total deposit of 0.0006 btc?
What can  do to retrieve my funds ?


texts:
I have a testnet connection with 3 clients. When I am doing getpeerinfo on 1 I am getting

[

    {
        "addr" : "172.20.61.111:63379",
        "services" : "00000001",
        "lastsend" : 1403246741,
        "lastrecv" : 1403246743,
        "bytessent" : 1074,
        "bytesrecv" : 1098,
        "conntime" : 1403246741,
        "pingtime" : 0.00000000,
        "version" : 70002,
        "subver" : "/Satoshi:0.9.2/",
        "inbound" : true,
        "startingheight" : 56114,
        "banscore" : 0,
        "syncnode" : true
    },
    {
        "addr" : "172.20.53.82:63416",
        "services" : "00000001",
        "lastsend" : 1403246741,
        "lastrecv" : 1403246743,
        "bytessent" : 149,
        "bytesrecv" : 1098,
        "conntime" : 1403246741,
        "pingtime" : 0.00000000,
        "version" : 70002,
        "subver" : "/Satoshi:0.9.2/",
        "inbound" : true,
        "startingheight" : 56114,
        "banscore" : 0,
        "syncnode" : false
    }
]

as a result of syncnode false this node is not syncing. How do I fix this?


texts: How can one sign a message to prove ownership of a BIP47 reusable payment code?

texts: Is there a way to sign a message and prove that an entity owns a BIP47 reusable payment code? How can this be done via js if available?


texts:
I'm trying to create a bitcoin address with the bitcoin-python library.  I tried this code:

import bitcoinrpc
bitcoinrpc.connect_to_local().getnewaddress()

But I got this error:

error: [Errno 10061] No connection could be made because the target machine actively refused it

I am running the bitcoind daemon.  Why am I getting this error and how do I fix it?
or can someone direct me to an easier way to learn to develop with bitcoin -


texts: I was wondering if some economists started to create a research group around BitCoin, or published academic paper on it. In general, I was wondering how BitCoin was analyzed and studied in academic research.


texts: Is there a way to prove ownership of a transaction?

texts:
Is it possible to prove that you are the sender in a transaction?
Prove this to 3rd-parties, not only the receiver.


texts: What is the point of downloading the blockchain?

texts:
I have Bitcoin-core on my mac, and currently it is syncing.

But what exactly is the point of having the entire blockchain downloaded onto your computer? Is it only there so that you can have an offline wallet?

Or, are there other benefits to having it on your computer...and if so, what would they be?


texts: Why isn't the block hash used to calculate accumulated work?

texts:
Why is this idea flawed? It doesn't seem to be a bad idea at first, because the miners should be incentivized to extend existing chain, instead of to "remine existing blocks", since such "remining" apparently requires more work to be done.

What's the actual reason? Because it would make double spending easier? Or it would enable miners to do selfish mining when they occasionally find a block with extra-small hash? Or it would cause more forks / require more confirmations?

I don't think this problem is duplicate with another question, because difficulty decides validity of a single block, while accumulated work decides best chain.


texts:
Just a quick question , in the blockchain api quoting from the documentation it says:

get_block_height

Get an **array** of blocks at the specified height. Returns an array of Block objects.

Params:

height : int - block height

why will it be an array? because i thought the blocks that are not on the main branch will be disregarded thus one height will only be one block?


texts:
I'm trying to send an OP_RETURN transaction, and the program says that I can't do it because it is over 80 bytes. I would like to send a transaction using OP_RETURN that stores data. There is a site called https://bico.media/, but I can't use it because I want to use the testnet.

Note: I know that this is bordering on off-topic, but it makes sense and is related to bitcoin. I want to ask how to send an OP_RETURN that large easily, and I think it would be applicable to bitcoin SV too.


texts: Where is the Signature stored in a SegWit transaction?

texts: I understand that SegWit makes transaction blockdata smaller, by not storing the signature in the Block, so that can fit more transactions in 1MB. This is because the signature is not anymore stored in the blockchain. The Signature makes nearly 70% of the data weight of the Block. So in a SegWit transaction it is 70% less stored in the Blockchain. But where are the signature stored if not in the Blockchain ?


texts: Can someone please explain how I can use OP_CHECKLOCKTIMEVERIFY or OP_HODL to lock funds until block 600000? I have been searching for a newb friendly script but the only ones I have come across is for nLocktime


texts: Are ripple transactions reversible like how a CC chargeback works?

texts: Does ripple take the properties of bitcoin where its irreversible?


texts: Does the bitcoin block contain minimal transaction detail? (Is it as private as possible given the proof-of-work design?)

texts:
From https://crypto.stackexchange.com/questions/508/could-one-prevent-double-spending-in-decentralized-digital-currencies-like-bitc

"Now, the only information about the transaction that needs to be public is enough information to prove I have the coins and prove that I didn't transfer them elsewhere. As it happens, the Bitcoin protocol leaks much more information than this (for example, the account I transferred the coins to). The protocol could have been designed to make less information public if that was desired."

Is this true, could the block-chain report less data but still gain the proof-of-work mechanism's benefits?  If so, what aspects of the blockchain are non-essential and what is the reason for including them?


texts: Why do we need revocation in both the offered/received HTLC outputs and HTLC timeout/success outputs?

texts:
The witness script for the output in the HTLC success/timeout transaction is:

OP_IF
    # Penalty transaction
    <revocationpubkey>
OP_ELSE
    `to_self_delay`
    OP_CHECKSEQUENCEVERIFY
    OP_DROP
    <local_delayedpubkey>
OP_ENDIF
OP_CHECKSIG

Which already exists a penalty transaction. While in the offered HTLC and received HTLC outputs in the commitment transaction, we have,

# To remote node with revocation key
OP_DUP OP_HASH160 <RIPEMD160(SHA256(revocationpubkey))> OP_EQUAL
...

Why don't we put the revocation in the HTLC-Timeout/Success outputs only?


texts: What if is there is no solution to a block?

texts:
Please let me know if I understand something wrong.

Let's say I want to create a new block and verify previous transactions. To do this, I need to:

Choose which transactions I want to include in my block
Calculate the Merkle Root of these transactions
I choose (?) a timestamp where I expect to 'create' this block (Is this a general concensus?)
I start to calculate hashes by concatenating above values and starting at nonce 0, increasing up to 2^32-1
When I find a hash with enough zeros, I announce my proof to the network and collect my fee

There's one problem here: there is no way to guarantee a solution exists. Since I expect mining pool members to all agree what transactions to include and which timestamp to use, it can be possible that for the given block no solution exists.

Of course, other miners also experience this problem. What if all 'big' miners choose blocks which do not have any solution? Could the network stall?


texts: Bitcoin Daemon - How to make a safe hotwallet?

texts:
There have been several Bitcoin exchanges robbed/hacked for all their Bitcoins over the past year.

One of the most recent being Flexcoin, and this is how they describe what happened.

  The attacker then successfully exploited a flaw in the code which
  allows transfers between flexcoin users. By sending thousands of
  simultaneous requests, the attacker was able to "move" coins from one
  user account to another until the sending account was overdrawn,
  before balances were updated.

My question is, how do we make using a hot wallet safe? Users need to be able to withdraw their funds from their accounts, but allowing them to do this opens you up for targeted attacks.

I was wondering if anyone could share some insight on ways to protect against these types of attacks?

I had thought of a few solutions but I noticed they have flaws in them.

1) Bob deposits coins into their deposit address and then Bob can only withdraw from the same address via the site. The problem is that Bitcoin Daemon only allows sendfrom  to  and not sendfrom  to  meaning that in order to do this you would need to create your own raw transactions.

Now normally this wouldn't be a problem, but when users fund their accounts using SharedCoin, it creates so many inputs that the size of the transaction is huge and thus requires more fees. Am I correct on this? I may be wrong.
It's also quite hard to be accurate on your account balances due to SharedCoin with so many inputs and outputs. Even Blockchain.info's account balances are sometimes incorrect due to SharedCoin.

2) When moving coins from Bob to Alice because Alice deposited fiat currency and wants to withdraw coins to their account, funds need to be moved to another address, possibly either a central address or Alice's withdraw address. If Alice sends simultaneous requests like someone did against Flexcoin, this could cause a problem. So again, you would need to use raw transactions so that funds can ONLY be sent from ONE address that preferrably only has enough funds to satisfy the withdraw request and no more in case of an attack.

Anyways, I think you all get the picture and I hope we can discuss some safe ways of doing this type of hot wallet approach?


texts: Is it necessary for all miner to reset mining when the tip of blockchain has changed?

texts:
Each block in the blockchain contains a pointer to the previous block (block header). If multiple blocks reference certain block as their parent, only the one that is part of longest chain is accepted.

Suppose that the hash of the current blockchain tip (last block) is 'A'. Two miner concurrently works on new blocks (containing different transactions) referring to A as a parent. Is it necessary for the slower miner to reset his work when faster miner finishes his block (with hash 'B') and broadcasts it, because the next block has to reference 'B' instead of 'A' as a parent?

If this principle holds, does it mean that slower miners have to restart their work more frequently because they are outrun by faster miners who publish their blocks and so change the blockchain tip?


texts: If I want to watch a public address, I need the hex string for that address, because the importpubkey command only takes a hex input. How can I convert a  base 58 address to a hex string using the bitcoin core?


texts: Running bitcoin-cli commands without hosting a node

texts:
I want to run bitcoin-cli commands (or JSON API requests) to see example response output in the format as given on https://bitcoin.org/en/developer-reference#bitcoin-core-apis without running bitcoind locally. I do not want to have to download the entire blockchain.

For example, I want to see the output of commands like gettransaction or getblock for transactions and blocks on the main Bitcoin blockchain. Aren't there any publicly available servers that would return responses in the format as specified in Bitcoin Core API? The other blockchain explorers like blockchain.info or blockexplorer.com appear to be returning a response in their own JSON format (i.e. document structure) with different field names and object hierarchy.

I spent quite some time looking for some such service but could not find any helpful information online.


texts: Does moving funds from one account to another locally require a transaction fee?

texts: I am developing a simple wallet with PHP. Right now I don't have the ability to "move" any funds around to test with. I am wondering does the "move" command require a transaction fee?


texts: Is there any tool to visualize the bitcoin transaction graphs?

texts: I want to visualize the bitcoin transaction graph linked to addresses that could potentially link my addresses and to better chose which coins I would use for which payment to prevent loosing privacy. Is there any tool that could help me build that graph and visualize the clusters that could be formed?


texts: BitInstant "Bitcoin Address" option is down!

texts: I want to cash deposit directly to my Bitcoin Address, but the option to do so has disappeared from BitInstant. Any ideas as to why? Do you think it'll ever be back?


texts:
What are the bare data necessities that a lightweight client would have to get from a server client in order to perform basic wallet tasks (show balance, transaction history, number of confirmations, send coins)?

For example, a simple, light client could store all Txs where any of the given addresses from the wallet were used, but one could also try trimming all data from those Txs that aren't related to their addresses.

What is the bare minimum of data a client needs in order to function?


texts: How does the Chinese Bitcoin ecosystem differ from the European/North American ones?

texts: What is the background of the whole Bitcoin ecosystem in China? Their market has been growing insanely in the last days... but I guess it can be very specific (different mentality of people, the Yuan, infrastructure etc.). How is their market different from the European/North American ones?


texts: How many confirmations do I need to ensure a transaction is successful?

texts:
As a regular user of Bitcoin, I often send bitcoins to other, or receive BTC from others, sometimes this might be a trade or deposit. Some traders require at least 6 confirmation, some require at least 3.

I want to how many confirmation is enough to ensure the transaction is successful?


texts: Can I use http command to place order in GDAX?

texts:
I see that I can read the price of bitcoin using

'https://api.gdax.com/products/BTC-USD/ticker'

Can I place and cancel the order via a http command?


texts: Why isn't Replace by fee default for all transactions?

texts: I know it's a wallet implementation and a flag, but when it was introduced why wasn't this change a rule for all transactions so that anyone could RBF if they wanted to instead having had to set the mandatory flag?


texts: Suggestions for hoarding strategy and technics

texts:
I've finally managed to figure out bitcoin, it's fantastic, now I have a goal of buying some coins while they're still affordable.

Please provide some advice for a fellow hoarder.
Just keeping all the sum in one wallet on a home PC is dangerous - what are the best ways to spread the storage? Physical bitcoins? Can you print one on paper (QR perhaps) and stash it somewhere? When keeping wallet on a removable media (e.g. flash drive), how many copies should I make? Should I even bother?

What's your favourite approach to keeping bitcoins you're not planning to spend right now?

Hints on the general strategy - how much to buy, how often, when to sell - are welcome too. Currently I plan to buy a few coins I can afford without noticing - a dinner worth of coins per month perhaps?


texts: Why does this transaction use the same address for multiple inputs?

texts: Why does this transaction include the same address multiple times? Was this done to "hide" the two other addresses where funds originated?


texts: Specific explanation of "timeout" configuration option in Bitcoin

texts:
According to Running Bitcoin - Bitcoin Wiki, timeout is described as following:

Specify connection timeout in milliseconds

To my understanding it would mean that if a response was expected, if not received in the specific time-range the client would drop connection.

A follow question is, would a node with a 15 second timeout hurt the coin network with a fast block-time of e.g. 45 seconds?


texts: Is there a widely used symbol for satoshi yet?

texts: Has a symbol been widely adopted for satoshi yet? I've seen Ș suggested but it's already a letter in Romanian. Ꞩ, Ȿ & ẜ (long s with stroke) all seem to be otherwise unused. Has anyone suggested using any of them?


texts: Bitconnect transactions show in block explorer, but one transaction is missing from wallet

texts:
My Bitconnect address 8Y7D6YfD7htnQ7uYaDHZzQSHtjiXRZfsZ9 has received 2 transactions according to this Bitconnect block explorer tool but only the smaller one for 0.01 is showing up in my Bitconnect wallet client. The other transaction for 3.44479734BCC shows around 6000 confirmations in the block explorer, but hasn't appeared in my wallet.

Why is this transaction not showing up, or at least, what I can do about it?


texts:
I would like to use the bitcoind daemon but I don't want the high CPU footprint related to validating blocks every time new blocks come in. There is a better equipped computer that I can rsync with, which would in theory allow me to just download the files and run:

bitcoind --daemon -connect=0.0.0.0 -checklevel=0

Note that I run connect=0.0.0.0 because I don't want new blocks to arrive directly on this computer, and checklevel=0 to prevent any block checks upon start.

I sync this with command:

rsync --progress --partial --recursive --size-only --verbose --delete -e "ssh -v" bitcoinserver:/home/jny/.bitcoin/blocks/ /home/jny/.bitcoin/blocks/  && scp bitcoinserver:/home/jny/.bitcoin/blocks/index/CURRENT /home/jny/.bitcoin/blocks/index/

So I sync the blocks directory and download the CURRENT file in the index directory. Through trial and error I found this to work. However, there is one problem: I still have a high CPU usage because of the UpdateTip function that runs to process the blocks (see: Why could UpdateTip be taking so long?).

However, if I do include the chainstate directory in my syncing, then I can not start bitcoin:

2014-07-25 12:03:36 Opened LevelDB successfully
2014-07-25 12:03:36 Opening LevelDB in /home/jny/.bitcoin/chainstate
2014-07-25 12:03:39 Corruption: 207 missing files; e.g.: /home/jny/.bitcoin/chainstate/452003.ldb
2014-07-25 12:03:39 : Error opening block database.

Do you want to rebuild the block database now?
2014-07-25 12:03:39 Aborted block database rebuild. Exiting.
2014-07-25 12:03:39 Shutdown : In progress...

I imagine that the problem is that the files in chainstate are being changed as I download them. Stopping bitcoind on the server while rsyncing is not an option, unfortunately.

Another disadvantage is that files in the chainstate directory seem to change a lot, which makes rsync download many of them over and over again, even though it could have been only a few hours since the last sync.

Any idea how to set up a more streamlined rsync of my bitcoin database?


texts: Is the Lightning Network susceptible to man in the middle attacks?

texts:
It seems like a man in the middle attack could be performed in a Lightning Network.

Let's say A opens a channel with B. If A manages to control all the connects B has to the bitcoin network (becoming a man in the middle), A can prevent B's attempts to propagate or publish refund transactions. In this case, A can send some money through B to another address A controls, then publish the original balance transactions. If A can continue to MITM B for the 10 days (or whatever) it takes for that transaction to go through, A would have successfully stolen all the funds A was able to convince B to transfer.

B could potentially become aware that either the blockchain data he's getting isn't valid or simply become aware the balance transaction has been published, but if he can't get on the bitcoin network to publish the refund, he's screwed.

Is this scenario possible?


texts: Litecoin miner crash with no apparent reason

texts:
I have a machine with 1 R9 X280 running on Intensity 13. It ran for 2 weeks with no problems, and now it's been crashing every day, or even up to 4-5 times a day. (Crashing as in  rebooting with no actual reason in Event viewer.)
The card is running at 73-76 Celsius; it is in an open case.
I tried disabling the CCC, but that didn't help.
What can I test to look for the problem? It is a brand new computer.
Details
CGMiner 3.7.2
Mining command:
cgminer --scrypt  -o x -u x -p x --gpu-platform 1 -I 13 -g 2 -w 256 --gpu-memclock 1500 --gpu-engine 1080 --gpu-powertune 20 --thread-concurrency 8192 --auto-fan --gpu-fan 30-75 --temp-cutoff 90 --temp-overheat 85 --temp-target 70


texts: Testnet Bitcoin Connection refused (111)

texts:
I have ah Raspberry and i will a BTC & Lightning node set up.
my bitcoin.conf
testnet=3
Bitcoind options
server=1
daemon=1
txindex=1
disablewallet=1
 Connection settings
rpcuser=raspibolt
rpcpassword=1212431
addnode=104.237.131.138
addnode=151.80.205.132
addnode=192.155.82.123
addnode=74.220.255.190
addnode=80.100.203.151
 Raspberry Pi optimizations
dbcache=100
maxorphantx=10
maxmempool=50
maxconnections=40
maxuploadtarget=5000

I have the addnode from this thread:
testnet3 node sync process is very slow
in the getnetworkinfo stands:
"version": 160000,
  "subversion": "/Satoshi:0.16.0/",
  "protocolversion": 70015,
  "localservices": "000000000000040d",
  "localrelay": true,
  "timeoffset": 0,
  "networkactive": true,
  "connections": 17,
  "networks":
  "warnings": "Warning: unknown new rules activated (versionbit 28)"

and in the debug log stands:
2018-04-24 17:39:51 connect() to 85.207.214.190:18333 failed after select(): Connection refused (111)
2018-04-24 17:38:16 connect() to [2001:470:c144:cafe::a]:18333 failed: Network is unreachable (101)

anyone have an idea where the error lies?
my testnet port: 18333 is open.
many thanks for the help!
regards


texts:
I am trying to install bitcoin-etl: https://github.com/blockchain-etl/bitcoin-etl to analyze bitcoin blockchain.
I have Mac OS and python3, I run this in terminal:

pip install bitcoin-etl

Also tried this:

python3 -m pip install bitcoin-etl
The output is:
ERROR: Could not find a version that satisfies the requirement bitcoin-etl

ERROR: No matching distribution found for bitcoin-etl

I have python3 and pip installed:
python3 -m pip --version
pip 21.0.1 from /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/pip (python 3.8)
Any suggestions?
Thanks!!!
P.S. BTW, if you know any other ways to analyze bitcoin blockchain (I need csv for block counts vs time) your advice would also be very appreciable!


texts: Buying from country A, selling in country B

texts:
I was curious as to whether is it legal/allowed to buy bitcoins (from a friend for example) from another country where the value is less and then sell the bitcoins in the UK, for a profit.

I'm new to bitcoin in general and still a student at University.

If this is legal to do, is there any information, or could you provide information as to how I would go about setting up a Bank Account that would accept large volumes of money going into the account due to bitcoin selling, as well as using that account to purchase bitcoins from abroad. And what are things that I should look out for, any legal issues etc?

Appriciate your time and help people.


texts: Bitcoin-QT client shows coins, but cannot find wallet.dat

texts:
It's been a couple years, and I opened my bitcoin-qt client.  It says I have coins, but is taking days to "sync with network".

Further, I cannot find a wallet.dat file anywhere on my system.

How can it know I have coins without a wallet?

I'm on the same computer I had two years ago, and didn't delete any files from my ~library/application support/bitcoin or any other bitcoin related files... sooo... befuddled.

Any insights, anyone?


texts: Has anyone ported the Bitcoin software to "pure" Clojure?

texts: Has there been any attempt to rewrite Bitcoin in Clojure? I know about BitcoinJ, so I imagine that should be easy to port. But what about a "pure" version? Without calling Java directly? Easily portable to Scheme or other Lisps-style languages? Thanks.


texts:
I have a wallet with several addresses. I would like to isolate one of the addresses in its own wallet, but I don't know how to do it. I've been trying with pywallet.py, but I've been unable to do it.

Can you help me, please?

EDIT: I've made some progress:

I dumped my wallet with pywallet.py --dumpwallet >wallet.json, and searched for the key I wanted to isolate, and wrote down the field named sec.
Then moved wallet.dat to another folder, and started bitcoin-qt, so it generated a new wallet.
Opened Help -> Debug window -> console and run importprivkey  XXXXXXXX mykeylabel. It took about 4 minutes to import the key.

Now I still need to:

remove this address from the old wallet.
remove the default address in the new wallet, so it contains just the imported address.


texts: How do I cancel my Unconfirmed Blockchain Transaction?

texts:
I am using blockchain.com.
I have made a bitcoin transaction of 0.0015 BTC to the address 1FCMXNiJTXB8pfEVpeaijtEAhcErW8Cbr1 . This is Coinexpay.cash exchange address.
You can see the transaction at https://www.blockchain.com/btc/tx/9486e1fb96f063b53dc782bdbc0dc0a898a9a26eef180e666f5b6dcb0c834428
I have paid the fees but it has been almost 12 hours and it still shows "Unconfirmed".
how do I cancel the unconfirmed transaction and get back my coins?
Help will be highly appreciated. Please directly write to me if can assist to recover my coins.(anthonio.sequeira@gmail.com). I can't resend more coin to that Address with higher amount. I either want it to be successful or cancel and receive my coins back.
Thanks for the help.


texts: json-rpc of bitcoin not working for testnet(curl command)

texts:
I am trying this command to get transaction from bitcoin testnet:

curl  --data-binary '{"jsonrpc": "1.0", "id":"curltest", "method": "gettransaction", "params": ["txId"] }' -H 'content-type: text/plain;' http://username:password@IP:PORT/

And i am getting following error

{ "result":null, "error":{"code" :-32601, "message" : "Method not found"}, id:curltext}


texts: Is it possible to write a transaction of bitcoins, having only pen, paper and a private key from the address with some unspent outputs?

texts: In my last answer I have done an allegation which I want to be proven or disproven. If this work possible, how much paper does it require? What kind of software needs Bob to send a transaction to miners?


texts: Very slow sync on low end PC - what to upgrade?

texts:
[Hi, I have to re-ask this question because I cannot recover my account from the last one. Sorry about that.]
I am a newbie to bitcoin. I am trying to sync a full node on my low end PC: 2g RAM, dual-core 2ghz, 250 gb regular HDD. Fresh install Linux. It is in pruned mode. The internet connection tests at 5mb download/1mb upload speed. The initial 15% synced in a few days but now the process is fluctuating wildly around 2-7 weeks. It's been on for a month & is only at 35%  right now... Suffice to say it is very slow.
My main questions are: how much will adding some RAM improve the syncing speed? And will adding new RAM reset the blockchain download? Also, I have heard repeatedly that using a SSD HD will help. Is there a way to carry over my present 35% progress onto the SSD, or do I have to re-start the process?
I have already adjusted these settings: dbcache=900, banscore=10, listen=0, server=1 (upnp=0 also shows up on the bitcoin core gui/options, but not in the config file.). I don't really understand what these settings do, I am just going off recommendations. So hopefully they are good(?).
I am worried that putting in the RAM will "reset" the blockchain download and I will have to start syncing from 0% again. This already happened to me when I was tinkering with the dbcache setting - Which I will have to do again in order to take advantage of any new RAM. (right?)
Anyway I hope that was coherent. Any response is very appreciated. :)


texts: After creation, what I have to do with a coinbase transaction?

texts:
I have create a coinbase transaction successfully with the command:

createrawtransaction '[{"txid":"0000000000000000000000000000000000000000000000000000000000000000","vout":0}]' '{"12Evb28oMpkP76HRS2CZ7VjNMD25B84VMv":12.5}'

what give a hex string for the transaction. But when I try signrawtransaction I got this error:

{
  "hex": "...",
  "complete": false,
  "errors": [
    {
      "txid": "0000000000000000000000000000000000000000000000000000000000000000",
      "vout": 0,
      "scriptSig": "",
      "sequence": ...,
      "error": "Input not found or already spent"
    }
  ]
}

with sendrawtransactions i got:

Missing inputs (code -25)

what I have to do with this transaction after create it?


texts: Please help. BTC has left Armory wallet and shows as gray, but says "Not in the blockchain yet"

texts:
I sent 1.5BTC in the usual way from my Armory wallet, but the transaction shows in gray as if it is still pending. When I click more details it says "Not in the blockchain yet".  If I search for the transaction on blockchain.info, there is no transaction recorded against the wallet ID I was sending to. I've also tried to send another small transaction a few times for 0.01 and 0.1 BTC to see if that works, but now I just keep getting an error.

  The transaction that you just executed, does not appear to have been accepted by the Bitcoin network yet. This can happen for a variety of reasons.

  On some occasions the transaction actually will succeed and this message is displayed prematurely. To confirm whether the the transaction actually succeeded, you can try this direct link to blockchain.info:

  https://blockchain.info/tx/e7c8737734ddba96337f...

  If you do not see the transaction on that webpage within one minute, it failed and you should attempt to re-send it. If it does show up, then you do not need to do anything else -- it will show up in Armory as soon as it receives one confirmation.

  If the transaction did fail, it is likely because the fee is too low. Try again with a higher fee. If the problem persists, go to "Help" and select "Submit Bug Report". Or use "File" -> "Export Log File" and then attach it to a support ticket at https://bitcoinarmory.com/support

However, the link to the armory support page is no longer active.

IN SUMMARY:
• The total amount in my wallet was reduced by 1.5001 BTC
• In the Armory transaction list, the 1.5001 BTC shows in gray as if it is still pending.
• I am unable to send any more bitcoins.

What do I need to do to retrieve the 1.5001 BTC to my wallet? Any help much appreciated.


texts:
I'm trying to understant this bitcoin chart, but there's no indication of what's the Y axis. The "200K" means the value in dollars? Or in bitcoins? Or what?

I'm trying to check out the value of a bitcoin in comparision with US Dollars over the year.


texts: What does this indicator mean in the right bottom cornor of the official Bitcoin wallet?

texts:
Circled in red:

When I hover over it I get the message "8 active connections to the Bitcoin network". Should Is this number too low and how do I change it?


texts: Please help! How do I transfer my wallet from bitcoin core to MultibitHD?

texts:
I (should by now) have bitcoins in my wallet,I sent them to my wallet whilst i was using bitcoin core but after taking days to sync (and it still hasn't synced) i have given up and installed multibitHD. I have tried using blockchain to import the data file but it keeps saying connection refused even thought the password is correct and the file is fine.

Now Bitcoincore wont even open so i cannot check whether it has synced or whether my bitcoins are still there and I'm beginning to worry that I've lost my money can someone please help me transfer my bitcoin core wallet over to multibitHD!?


texts:
Can anyone please provide a clear definition for what a Sybil attack is?
I was asked how the cryptocurrency I am developing would prevent Sybil attacks.


texts:
Can anyone explain me in the plain English how difficulty is calculated. I have a very approximate understanding that it is calculated based on the amount of hash power in all the bitcoin community over a specific period of time. But this is very vague.

Also I understand it can change very rapidly. Can it only increase? Is there any formula how to calculate it or predict it?

Thanks for a detailed answer, Meni Rosenfeld. Just to make sure I got everything right. I am summing up all the time, it took to generate the last 2016 blocks. And then apply the formula.


texts: What are the chances bitcoin big mining pools to unite and do 51% attack?

texts:
Looking at this bitcoin hash rate distribution chart (https://www.blockchain.com/en/pools), it only takes 3-4 mining pools to unite and do a 51% attack.

With this possibility, how can people still think that Bitcoin can be the money of the future?

PS: I'm also a bitcoin believer


texts:
I have this code:

from bitcoinrpc.authproxy import AuthServiceProxy, JSONRPCException
import logging
rpc_user='-------' #User name is hidden
rpc_password='-------' #Password hidden
logging.basicConfig()
logging.getLogger("BitcoinRPC").setLevel(logging.DEBUG)
rpc_connection = AuthServiceProxy("http://%s:%s@127.0.0.1:8332"%(rpc_user, rpc_password))
blockcount=rpc_connection.getblockcount()
print(blockcount)

The result:

DEBUG:BitcoinRPC:-1-> getblockcount []
DEBUG:BitcoinRPC:<-1- 94768
94768

Of course this is last block in my device, but I want the real last block.

Is there a "external server or a Web site" i can call instead of Local server '127.0.0.1'? (for sending the bitcoin RBC method)


texts: Using bfgminer on an Intel GPU on Ubuntu 12.04

texts: I am currently running Ubuntu 12.04 LTS on an i5 core and Ivy Bridge GPU. Using bfgminer I have successfully mined on my CPU, but my GPU is never recognized. I have installed OpenCl for Intel processors. I had my friend test his GPU using bfg on Win7 and his worked out-of-the-box. I would like to know how to use my Intel HD 4000 graphics for mining with bfg and Ubuntu.


texts: Do banks exchange bitcoins to traditional currencies

texts: If someone was not concerned with the anonymity aspect of bitcoin, can he/she exchange traditional currencies to bitcoins and vice versa from banks? Do banks do this? and if not, why?


texts: Why does bitcoind (0.7.2) give an error when trying to issue getrawtransaction over RPC?

texts:
I am writing an web application using Python/Flask. I am using

http://laanwj.github.com/bitcoin-python/doc/

to connect to my bitcoind 0.7.2 server as follows:

conn = bitcoinrpc.connect_to_local()
accounts = conn.listaccounts(0)

This is all working well. However, when I attempt to use some of the newer raw transaction calls, I get an error. For example,

raw_transaction = conn.getrawtransaction(txid)

results in the following error:

AttributeError: 'BitcoinConnection' object has no attribute 'getrawtransaction'

It seems (though I am not sure) that the methods that don't work for me are those that are listed here:

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

Thanks to anyone who can help on this.


texts: how does bitcoind functions in bitcoin exchange model?

texts:
i mean exchange allows every users a unique BTC deposit address

different users sends btc to different addresses but BTC endsup in same wallet

can i create multiple receiving address by bitcoind (getnewaddress)  or i will have to use HD wallet for that for our users (we are building lotto system on bitcoin)


texts: Miner transaction selection - how are sigops considered?

texts:
There is a limit on how much a block can sigop (set to 80000?). There is also a limit on how much a single transaction can sigop (set to 16000?). It thus seems possible (and if it's not possible, the remaining of this question is void, but then how is it prevented?) that an attacker submits five special transactions to consume the whole block sigop limit.

If such attacking transactions are using very generous fees per byte, if the miner chooses which transactions to include in a block based on fee per byte metric, it would include the attacking transactions in a block, getting relatively huge fees per byte, but not filling the block because of sigop limit. This would mean that the miner could get more in fees if it avoided attacking transactions, but the question is whether such selection avoidance is implemented by default.


texts: Which tool can I use to calculate the best fee for a specific time?

texts:
Let's say I'm okay with a transaction to be included in a block in about 24h.
The fee is obviously dependent on the network congestion.
Which (online) tools can I use to calculate the optimal fee given current network activity?


texts: Would backing up my private key be enough?

texts:
Lets say I put my wallet's private key on a rocket and fire it towards mars.  In 50 years time I travel to mars for a cheap vacation and find my private key.  Would I then have full access to my wallet, including all the transactions over the past 50 years and the current balance (from when I landed on mars in person) etc?

In other words, to fully backup my wallet and be able to restore it with full control, do I only need to backup my private key?


texts: Sign Multisignature Transaction with only 1 of the needed keys using BitcoinJ?

texts:
If I have an unsigned Raw Transaction whose inputs are from a multisignature wallet, can I sign the transaction with only of the N needed keys and having the output as raw transaction again using BitcoinJ and/or Java native cryptography libraries?
The case I want is the same as this page of Coinb.in: https://coinb.in/#sign So I have as input a raw transaction and a private key, and also the multisignature redeem script if needed, and i want in output the raw transaction with the signs that were before (if there were signs) + the sign from the private key i provided as input.


texts: Bitcoin Core full node has saved a lot more space than 260gb

texts:
I've had Bitcoin Core running on my Macbook i5, 8gb ram, the last five nights and have gotten to 58%. It's downloading to an external hdd and now the blocks directory contains 375gb of data.

Another computer, Huawei laptop i5 8gb ram, started downloading it yesterday and has gotten to 61% with just under 200gb or storage space used. Although this computer first downloaded to its internal ssd and then I copied it to the hdd. Now its crashing all the time in the same way the first has been for the last days.

I cant figure out why its saving more than the original blockchain. Why is this?


texts: Why is a minimum transaction fee for 0.01 BTC *sometimes* enforced

texts:
I have read Why would Bitcoin-QT attempt to charge a processing fee, when I have my transaction fees set to zero? but I still have a question.

I am sending 0.01 BTC from my wallet to my Ethereum intermediate address and then back again, so as to verify recoverability.

Sending 0.01 BTC worked fine without transaction fees. When sending it back I get "The total exceeds your balance when the 0.0001 BTC transaction fee is included." although fees are set to zero.

Why is there a fee requirement in one direction only?


texts:
Probably been asked a lot, but I'm unable to find answer. I wanted to ask, how to do I send from btc rpc to another address inside or outside rpc.

I been looking at these calls sendtoaddress , createrawtransaction , signrawtransaction and sendrawtransaction and I'm a bit clueless...

On side of that, how do I get amount of fee I need to pay when doing transaction.


texts: What's the relationship of Bitcoin addresses to public keys?

texts:
A Bitcoin wallet can handle multiple private keys.  In ECC, you can have 2^256 private keys, and for each key, you can have 2^256 public keys.  Assuming that's right (please correct me if I'm wrong), you generate a Bitcoin address basically by hashing a public key with a RIPEMD160 hash function, which can produce 2^160 different addresses.

Is the relationship between the Bitcoin address and the public key 1:1 (one address for each public key)?  If not, how is it possible to connect more than one address to a single public key, since this "connection" is made through hash functions and the hash for one entry (the public key) doesn't change unless you change the entry itself?

Thanks in advance.


texts: Why countries like to create their own cryptocurrency?  As far as I know, a good cryptocurrency should have independent of a third party.


texts:
Exactly when was the first block mined and the first bitcoins generated? How many people knew about the project at this point? Had the project been publicly announced before the first block was mined or did that happen afterwards? Is there anything special about this first block or could anyone have mined it?

I realize that there are a number of questions included here but I don't think that it makes sense to ask them separately.


texts: Is the public address for Tesla's wallet known?

texts:
I understand if this isn't likely the place.
It has been all over the news that Tesla has bought 1.5 billion in bitcoin. I'm curious if tesla's public wallet address(es) are known?
If they are not known, what is the most likely culprit? shouldn't it be public information?


texts: Private key of 44 chars? (old Blockchain.info wallet)

texts:
I'm trying to sweep some coins from an old (blockchain.info) wallet.
I decoded the wallet I have and it gave a private key as a 44 char alphanumeric string starting with 9.
This doesn't seem to be a standard format. I tried to base-64 decode it but it turns out a mess.
Any ideas on how to convert this into a WIF so that other wallets will recognize this?
Thanks!


texts: Can we I identify crypto-exchange (BTC) hot wallets?

texts:
I am interested in understanding, how the large crypto-exchanges handle deposits and withdrawals of BTC. I am aware of some examples of ETH-related hot wallets which are rather easy to identify but it seems to me this is not the case for BTC. I tried the following:
- Deposit and Withdrawal funds from my trading wallet at different crypto-exchanges (poloniex, kraken and bitfinex)
- Trace back the initiator wallet of these transactions.

Seems like they are kind of using several in- and outputs to hide the actual flows.

So my question: If I am interested in tracking (approximate) BTC-flows between the different crypto-exchanges, what would I have to do?


texts: BTC recovery from registration details without wallet.dat

texts: I started mining march 2009, i remember registering. is there any way to get my BTC back from the registration process? I know you need the wallet.dat and the password or key to access the BTC, but is there any way to get my BTC back. I am desperate, the fact that i know i have money out in the ether, but yet have none is killing me. I vaguely remember when i signed up they just added a registration process that linked my info to the coins i generated in 03/2009. I know there are lists of dormant addresses, can they be used to get my BTC back? Please help


texts: If I lost my public keys, could I recover them from the private key?

texts:
Possible Duplicate:
  How are public & private keys in an address created?

If I lost my public key, but still have the private key, is it possible to recreate the public keys.

How many public keys can be made from one private key?

Is it a computationally expensive process to create all the public keys from one private key?

Sincerely,

Joe.


texts:
are any of the following transaction malleability "attack" vectors currently feasible?

alter scriptsig from:

OP_PUSHDATA <sig> OP_PUSHDATA <pubkey>

to one of:

1) OP_1 OP_SHA1 OP_DROP OP_PUSHDATA <sig> OP_PUSHDATA <pubkey>
2) OP_PUSHDATA <sig> OP_PUSHDATA <pubkey> OP_1 OP_SHA1 OP_DROP
3) OP_PUSHDATA <sig> OP_PUSHDATA <pubkey> OP_NOP

so that the corresponding scriptpubkey still evaluates to true:

OP_DUP OP_HASH160 OP_PUSHDATA <address> OP_EQUALVERIFY OP_CHECKSIG

i can't tell if this is handled by point 6 in bip 62 or not:

  Superfluous scriptSig operations Adding extra data pushes at the start of scripts, which are not consumed by the corresponding
  scriptPubKey, is also a source of malleability.

judging by the code it looks like it has been taken care of, but my c++ knowledge is not great...


texts: If cryptocurrencies have no intrinsic value, how do they originate?

texts:
In theory, anyone could create an infinite quantity of their own cryptocurrency right now. However, if you were to do this, it would have no value and, thus, it would be useless.

Since value comes from demand, how is it possible to create something from nothing and expect people to pay for it?


texts: Saved bitcoin dat file, unfortunately converted to Adobe

texts:
Is there a way to convert back or what do I do?   I would have thought that the old dat files would still be somewhere on my PC.  I never put them in a wallet ( .1 BC) so it was just a bunch of files. If i can access them, which ones do I need & how would I transfer them to a Trezor1 ?

Thank you

i can find this, is it usable to move the data to my wallet ?

C:\Users\Doug\SkyDrive\Documents\bitcoin (2016_09_09 22_16_58 UTC) (2017_08_22 13_54_01 UTC).dat


texts: Where can I find the technical discussion between Satoshi and other contributors in the sourceforge website?

texts:
Where I can find the technical discussion between Satoshi and other contributors in the sourceforge website?
I read the book of Satoshi in spanish and really excited about his comprehension of the economy especially for Satoshi. I was disappointed because couldn't find the technical concepts.
I'm Searching the comments in the forum especially Satoshi with Hal Finney
Where can I find all the comments?


texts: Can I buy bitcoins with moneygram in Australia?

texts: I notice you can do it like this in the U.S http://vimeo.com/44849463 but is the same method possible in Australia? We do have moneygram at 7-11's here.


texts:
I am getting a message when I start bitcoind :

Config options rpcuser and rpcpassword will soon be deprecated. Locally-run instances may remove rpcuser to use cookie-based auth, or may be replaced with rpcauth. Please see share/rpcuser for rpcauth auth generation

What is cookie based auth and how can I use it ?

Thanks