texts:
I have been reading about transaction malleability a lot still doesn't make sense to me.
Is there a script I can use to test it out ?
If the transaction that is malleable is changed by the attack, how is it possible that the two transaction are still in the blockchain and the miners still pick the attackers TXID over the legitimate one?
Why our legitimate transaction not seen by the miners?


texts: What is the most effective way to buy bitcoin from swiss francs?

texts:
The most effective way I could find so far was Mt.Gox. The costs that are involved are still quite prohibitive. But this then boils down to the question: what is the most effective way to get your money out of [Insert your Exchage here]-exchange.

Is there any better way to convert your currency? (Swiss Francs in my case)


texts: Bitcoin Core - server uptime, privacy and security questions

texts:
For now, bitcoin core has to run on my main computer. Once the block chain is downloaded, I see instructions that I can leave it running only 6 hours a day. OK. I can do that at night. I assume I also need to turn it on any time I want to view my wallets, make payments, and recveive payments. No problem.

What about securituy? I live in an apartment building with shared Internet access - quite amazingly fast too. I don't know how secure I am from other apartment dwellers or from the Internet. Advice here? Should I only have the core on when using TOR or proxy or both? Can a sender or receiver discover where I live if I don't use TOR and/or proxy?

Thanks,
 - J


texts: Can I do transactions while Bitcoin Core is being synchronized?

texts:
How long does this process take? It is telling me 46 weeks left but its doing this for months. How do I speed of the synchronization?

I downloaded it from their website. It is the latest version of Bitcoin Core. Windows 10, 4.00GB 64 Bit


texts:
Let's say I'm a photographer, and I want to sell my photograph as if it were fine art, so there's a limited edition print, or even just one which has been signed by me and can be thought of as genuine.

Now, I know that there will be copies of the picture itself, because there's always easy ways, but how can I attach my photograph to a bitcoin or a portion of a bitcoin and thereby add value to the bitcoin and value to my phtotographs?

I  know colour coins are in the works, but lets turn it around. A bitcoin has no substance right? But what if instead of a wallet with a number inside, you could have a stack of bitcoins each with different pictures attached? It would be like a personal art gallery, cover flow with money.

Any ideas on this?


texts: How should centralized wallets handle user accounts?

texts:
I tried to generalize this question from one I asked on the BitcoinJ development list.

I'm working on a project that requires a centralized wallet. From what I gather, these types of services generally rely upon simple balance checks to ensure that an individual user doesn't spend more than is in their wallet. That is, all users share a pool of keys, and the only thing tracking each user's balance is the service's database.

The Bitcoin daemon exposes functionality not in the GUI, namely that of accounts. An account is a string that groups keys. You can send from an account, and it will only gather coins owned by the keys in that account. This is beneficial, but is fairly limited. Using this however, you could have each account be a unique identifier for a user, and then that user "owns" the associated keys. One seeming drawback to this is that there is one centralized location to change ownership of an account.

I came up with a potentially better solution. Each account "owns" one or more public key hashes (the meat of a Bitcoin address). When creating a transaction, the service will transmit these hashes, letting the wallet know that when scanning unspent outputs, only use those with a public key hash owned by the user. In this way, without associating a user account with the private key itself, we are able to allow the user to have exclusive access to any number of keys.

Does this seem like a good solution to the problem? Is there something better that I'm missing?


texts: When people talk about possible changes to how Bitcoin works they sometimes say a particular change would require a hard fork. What does that mean? Can a hard fork cause problems?


texts: Cryptofinance plugin pulling wrong data for KNC

texts: Seems there are two "KNC" tags on Coinmarketcap... Kyber Network and KingN Coin. Any idea how I should pull the Kyber Network data using this plugin? Right now it's pulling the KingN Coin info...


texts: Can you run a full Bitcoin node on Node.js?

texts:
Are there bitcoin full node implementations running on Node.js?
Node.js is the server side language that I'm most familiar with so I was wondering if I can run a full bitcoin node on Node.js?
I just want to learn more about how a node works and possibly experiment writing my own cryptocurrency implementation in Node.js as that's what I'm most comfortable with.


texts: CreateRawTransaction and SendRawTransaction how to specify transaction fee?

texts:
I am able to createrawtransaction and sendrawtransaction but how am I able to specify a transaction fee for the miners?

I am looking at possibly large transaction sizes due to multiple inputs (around 100) and I have had a few of them never show up to their destinations and some of them do show up. I am assuming this might be due to the lack of transaction fees since I am using the exact same code to send both raw transactions.

So again, how can I specify a transaction fee in Bitcoind with creating a raw transaction.

And by the way, I am spending the funds from a multisignature address, in which 2 of the private keys are not controlled locally, so settxfee will not suffice. I want to write it into the transaction itself.


texts: What is the maximum number of signature check operations a transaction script can request?

texts:
As transaction size, the number of signature checks per transaction can affect client performance and the inclusion of many O_CHECKSIG opcodes could be used as a tool for denial-of-service attacks.

I found in CTransaction::AcceptToMemoryPool() the following check:

// Rather not work on nonstandard transactions
    if (GetSigOpCount() > 2 || ::GetSerializeSize(*this, SER_NETWORK) < 100)
        return error("AcceptToMemoryPool() : nonstandard transaction");

Then I suppose the OP_CHECKSIG limit is 2, which is fine for security but this limit prevents users from using the advanced contracts Bitcoin is suppose to allow.

Also there is the limit imposed by MAX_BLOCK_SIGOPS, but the limit applies to whole blocks, and only indirectly limit the sigops of a single transaction.


texts: Find recipient of a bitcoin transaction?

texts: Is there a way I can identify the recipient of a Bitcoin based on the transaction information? I have transferred Bitcoins a few years ago somewhere (possibly to Evolution marketplace, which was a scam) but I don't remember for sure where it went.


texts: Why is Enjoy Sochi a malicious spam attack

texts:
I recently read the following thing on reddit:

  The two transactions for .00000001 BTC are a malicious spam attack.
  They were sent without fees, which means that if you wallet doesn't
  allow you to choose specific outputs your balance is tied up until
  those transactions confirm.

Surely this is a spam (although I can not understand what is advertised), but I can not understand how is it a malicious attack. What exactly can be achieved by this attack?


texts:
I have a problem that wallet does not recognize transactions of my address. The problem is present on testnet.

Relevant address is n3qPR7uHUSoqnd8DZpE8GVhqnmrMzYu7Vj (https://testnet.blockexplorer.com/address/n3qPR7uHUSoqnd8DZpE8GVhqnmrMzYu7Vj).

bitcoin-cli validateaddress n3qPR7uHUSoqnd8DZpE8GVhqnmrMzYu7Vj
{
  "isvalid": true,
  "address": "n3qPR7uHUSoqnd8DZpE8GVhqnmrMzYu7Vj",
  ...
  "ismine": true,
  ...
}

Transaction 405920020c236f3faa483b72baf5181955ac25f8946323f9f0827b94e08a2850 (https://testnet.blockexplorer.com/tx/405920020c236f3faa483b72baf5181955ac25f8946323f9f0827b94e08a2850) is having my address as an output:

bitcoin-cli getrawtransaction 405920020c236f3faa483b72baf5181955ac25f8946323f9f0827b94e08a2850 1
{
  "txid": "405920020c236f3faa483b72baf5181955ac25f8946323f9f0827b94e08a2850",
  ...
  "vin": [
  ...
  ],
  "vout": [
    {
      "value": 0.49953560,
      "n": 0,
      "scriptPubKey": {
        ...
        "addresses": [
          "mxiFoE5bNxXMRdgXyFrc6zW3aw7zsuynSK"
        ]
      }
    },
    {
      "value": 16.05588800,
      "n": 1,
      "scriptPubKey": {
        ...
        "addresses": [
          "n3qPR7uHUSoqnd8DZpE8GVhqnmrMzYu7Vj"
        ]
      }
    }
  ],
  ...
}

But my node does not recognize it:

bitcoin-cli listunspent 0 9999999 "[\"n3qPR7uHUSoqnd8DZpE8GVhqnmrMzYu7Vj\"]"
[
]

bitcoin-cli gettransaction 405920020c236f3faa483b72baf5181955ac25f8946323f9f0827b94e08a2850
{
  "amount": 0.00000000,
  ...
  "txid": "405920020c236f3faa483b72baf5181955ac25f8946323f9f0827b94e08a2850",
  ...
  "details": [
    {
      "account": "",
      "address": "mxiFoE5bNxXMRdgXyFrc6zW3aw7zsuynSK",
      "category": "send",
      "amount": -0.49953560,
      "fee": -0.00046440,
      "abandoned": false
      ...
    },
    {
      "account": "",
      "address": "mxiFoE5bNxXMRdgXyFrc6zW3aw7zsuynSK",
      "category": "receive",
      "amount": 0.49953560,
      ...
    }
  ],
  ...
}

Rescan of the node didn't help.


texts: What mining parameters are not modifiable with ASIC miners?

texts: When ASIC mining devices ship, what parameters of mining become hardcoded? How would these ASIC mining devices respond to any changes to mining procedure / algorithms?


texts: History of ideas behind a bitcoin protocol

texts:
Could you outline the logical sequence of main ideas (concepts) that contributed to the evolution of the bitcoin protocol from the beginning
to now?


texts: P2SH-P2WPKH private key or revert to P2WPKH

texts:
Is there a way to get the private key out of an P2SH-P2WPKH address, using Bitcoin Core 0.15.1?
If not, is there a way to get the origin P2WPKH address to get the private key out of this address?


texts: In the NXT register alias dialog pop up, what is the DEADLINE text field for?

texts: What is the deadline text field for in NXT register alias?


texts: Are there any blockchain's that has a built in tumbler or coin shuffling technology built into their code?

texts: I know dash has some kind of mixing technology in their blockchain using their master nodes, but are there any other blockchains that has a built in coinjoin or coin shuffling technology built into their code? I know Monero uses ring signatures, but I'm more interested in just coinjoin or coin shuffling technology that is in blockchains. I know it might not be 100% private.


texts: What is lnprototest exactly? Can it be used to test an individual Lightning implementation or just interoperability between implementations? What does an implementation need to do to use lnprototest?


texts: Funds from coinbase never showed in my Multibit wallet

texts:
I know this question has been asked and answered a bunch of times so I am sorry for doing the same. I am basically a moron when it comes to this stuff and very new to digital currency.
So here's the deal opened an account with coinbase got my funds in there. I tried to use bit coin-qt but that has been syncing for literally 10 days now so I used multi bit instead. Did a small $5 transfer from CB to my MB wallet no problems I even figured out how to send it to someone else after that. Here is where the problem starts I went to deposit more funds from CB to my MB wallet using the same wallet. CB went through the pending process which took about an hour on the CB site it says transaction went through but the funds never arrived in my MB wallet. I tried resetting my blockchain and nothing. So now I see all of the kind folks on here talking about going to the GO function ( I run Mac OS ) or searching hidden files or searching something like ~librara/username/.wallet or something of the sort. So like I said in the beginning I am a moron and know nothing about what that means. Please help me figure out where on my computer that wallet and money went. Oh and bye the way the bitcoin wallet address still shows in my wallets list and its the same address that CB sent the funds to. Thanks in advance for any and all help


texts: Knowing a single transaction can you track down a Bitcoin user?

texts:
I have used this transaction to donate to Wikileaks. I have applied no special techniques to obsure my identity. How much information can find out about me on the blockchain. What tools would you use?

Can you guess the following information? Can you prove it?

How did I get the bitcoins I was donating?
What else did I use my bitcoins for?
What was my total bitcoin balance at a given time?
What wallet am I using?

Please try not to violate other people's right to privacy.


texts: getting balance from my address using bitcoinj

texts:
I can get my bitcoin balance from private key but when i tried retrieving from my address its not possible posted below my code can any one tell me what i'm doing wrong

public static void main( String[] args )

        {
            NetworkParameters params = TestNet3Params.get();
            WalletAppKit kit = new  WalletAppKit(params, new File("."), "sano");
            kit.start();
            kit.isRunning();
            Address address = new Address(params, "mj255GgoGKN6uTjtWdNcF7obu88iLSTZdm");
            boolean add =kit.wallet().isAddressWatched(address);
            Wallet wallet = new Wallet(params);
            DumpedPrivateKey key = new DumpedPrivateKey(params,
                   "cTH6YyRZSqF8VvtjkfqABqjGF682cQkW3mMuageraH4CEzCrweqT");
            wallet.addKey(key.getKey());
            wallet.addWatchedAddress(new Address(params, "mj255GgoGKN6uTjtWdNcF7obu88iLSTZdm"));
            BlockChain chain = new BlockChain(params, wallet,
                   new MemoryBlockStore(params));
         PeerGroup peerGroup = new PeerGroup(params, chain);
         peerGroup.addPeerDiscovery(new DnsDiscovery(params));
         peerGroup.addWallet(wallet);
         peerGroup.start();
         peerGroup.downloadBlockChain();
         BigInteger balance = wallet.getBalance();
         System.out.println("Wallet balance: " + balance);
}

Edit 1: The below given code retrieves balance from address but each and everytime it is creating a new address.

public static void main(String[] args) {

    NetworkParameters params = TestNet3Params.get();

    String filePrefix = "forwarding-service-testnet";

    WalletAppKit kit = new WalletAppKit(params, new File("."), filePrefix);

    // Download the block chain and wait until it's done.
    kit.startAsync();
    kit.awaitRunning();

    List<Address> list = kit.wallet().getWatchedAddresses();
    if (list.size() < 2) {
        kit.wallet().addWatchedAddress(kit.wallet().freshReceiveAddress());
        System.out.println("New address created");
    }

    System.out.println("You have " + list.size() + " addresses!");
    for (Address a: list) {
        System.out.println(a.toString());
    }

    String balance = kit.wallet().getBalance().toFriendlyString();
    System.out.println(balance);
}


texts:
Once my public wallet address is known, is there anyway to deny payments to that wallet?

For example, if I want an external authority to regulate who can pay into a wallet, is that possible?

I guess a related question is can I turn a wallet 'off' once it is in the block chain and known.


texts: I have a bitcoin address , how do I check how much bit coin I have

texts: How can I check my bitcoin address. I have the address but how do I access it


texts: Changed Merkle Root and Genesis Hash - Not Compiling

texts:
I am kindly asking the expert programmers of this wonderful forum to enlighten me on why the updated QT I have created, does not properly open when running ./stonecoin-qt , but rather dumps core and shows the incorrect genesis block for the -testnet flag

after updating all the parameters in the github repo below

  https://github.com/advantage-project/stonedfork

  ./autogen.sh && ./configure && make

I have updated all the information inside the chainparams.cpp (public keys, magic bytes, spork keys, genesis, merkle, everything) and successfully recompiled to update and reflect the changes I have made

however when I attempt to run either the daemon or qt mainnet or -testnet it fails to properly open and instead aborts and dumps the core, however when I leave the original details in, it opens perfectly fine.

What do I need to do after changing the merkle and genesis in the src to successfully run the QT GUI or daemon without crashing?

**(also, when I run the ./stonecoin-qt -testnet , it shows the main net genesis hash, rather than the testnet genesis hash, which is different)

Thank you :)


texts: How is the Leaf node weakness in Merkle Trees exploitable?

texts: Recently a weakness in leaf nodes of merkle trees was disclosed and it is claimed that this issue is exploitable to trick SPV nodes. How does the weakness make SPV nodes vulnerable to attack? What would an attacker do to exploit this attack?


texts: How many Bitcoins existed when block 209,999 was mined?

texts:
This article claims there are now 10,499,925 bitcoin (at the time of the reward drop from 50 to 25).

Weren't there supposed to be exactly 21,000,000 / 2 = 10,500,000 BTC mined at this point? What am I missing?


texts:
i put in my identifier to log in and it stays stuck on the log in page.
It says "changing wallet identifier" and doesn't let me log in.  After a while, it says that they disabled login for too many attempts.
I have not been able to log on for the past 2-3 days.
please help.


texts:
I'm excited because I bought my first bitcoins today! (0.41 bitcoins at that!)
I'm wondering how they are put in to circulation? From my understanding it seems that the algorithm generates x bitcoins every hour, where x is a diminishing value, until eventually zero coins are being created... so let's say an hour from now 5 bitcoins are created... Where are they created and how are they put into circulation? Or are they created evenly throughout everyone's wallets and just distributed evenly (in which case I might receive 0.000001 bitcoins in the next hour?) And what is a bitcoin miner?

Also, what happens if my computer is destroyed and my wallet file with my bitcoins is lost? Are those bitcoins gone forever? Wouldn't this cause the supply of bitcoins to go down overtime until eventually there are very few bitcoins left?

Thanks! God bless!

(I bolded my 3 questions so that they are easy to find and answer).


texts: What's the difference between a bitcoin client and wallet?

texts: I would like to know what is the difference between a client and wallet.


texts: C secp256k1 : what is the purpose of secp256k1_context_randomize?

texts: In the course of studying the secp256k1 library API, I came acrosssecp256k1_context_randomize which seems similar to providing a seed to a pseudo-random generator. At the same time, the file secp256k1.h seemingly does not offer any functionality for generating random private keys, and the function secp256k1_ecdsa_sign relies on a deterministic secret (rfc 6979) rather than anything randomly generated. Now I can see the API being extended in file secp256k1_ecdh.h with the function secp256k1_ecdh which returns an EC Diffie-Hellman secret. But this doesn't seem to rely on random generation either since the scalar is provided as argument. So I am wondering, why would a user care to randomize a context, or in other words, where is randomization used with the library?


texts: Why blockchain.info pays network fees by themselves

texts:
I'm exploring ways of accepting payments and thinking about blockchain.info
Receive Payments API.

I can't realise why this service going to pay network fees instead of me. Where the profit? I see only loss.

Can someone explain why they pay fees?


texts: How do developers fix bugs when compiling takes so long?

texts: It takes so long to compile Bitcoin Core on my machine... I can't imagine trying to fix bugs like a missed semicolon and having to wait an hour for the compiler to finish before testing. Is this really what devs have to deal with? Or is there a way to just compile smaller units of the code and run it quickly over and over again until all the semi colons are fixed?


texts: Bitcoin Core goes totally out of sync after pc crash

texts:
i've been trough 10+ days of syncing the Bitcoin Core and again mSigna wallet with Core...

downloaded bootstrap, then building blocks for Core to get synced was relatively fast, but mSigna has to build blocks for itself all over again while synced Core has to be running in the background. Its taking ageeees! way slower than the Core, especially last 100.000 blocks.)

And the 1.8 BTC are waiting in the unspent outputs on the blockchain cause i generated address for transaction from mSigna before when it was out of sync. (apparently you can do that in mSigna) just hoping when it gets synced i will see my coins in vault.

But the actual problem is that while mSigna was syncing(was at around 85%... 330.000+ blocks synced)  and the Core was normaly synced i suddenly got BSOD and computer restarted. Normaly first I opened bitcoin core to resume the process but now the Core is completely out of sync, and the blocks in bitcoin qt folder  are using 60 GB of space which means they are already builded..?
How can i tell the Core to use those synced blocks?
I will not open mSigna till the core is not synced again cause im afraid that msigna will restart aswell.
Thanks.


texts: Won't ASIC miners eventually break SHA-256 encryption?

texts: I might be confused as to how Bitcoin works, but as far as I can tell, ASIC miners are getting better every year and faster at cracking SHA-256 encryption.  Won't this cause the eventual complete obsolescence of SHA-256 encryption entirely, much faster than previously estimated?


texts: What are the minimum and maximum length of a Mainnet Bitcoin address?

texts:
The wiki says that

A Bitcoin address is an identifier of 26-35 alphanumeric characters.

Is this information up-to-date? Even the Bech32 address bc1qar0srrr7xfkvy5l643lydnw9re59gtzzwf5mdq given as an example on the same page  has 42 characters.
Some other Bitcoin mainnet address examples:

bc1zqyqsywvzqe has 14 characters.
bc1qwxlm0dtlgsfv9qqyvv20mu5l82cn59xs20587rh8j6vym77km0vq3xqmca has 62 characters.

Before you say that this is duplicate, I know that What are the minimum and maximum lengths of a Mainnet Bitcoin address? asks the same question. However, I do not have enough reputation to add a comment there.


texts:
Everybody knows that bitcoin blenders anonymize your coins but shouldn't you follow some precautions for your mixing to be effective? I suppose that mixer is fair (it won't steal your money and does not trace anything) but if it simply takes n amounts from various users, and sends them to n destination addresses then operation is meaningless. What should proper mixer fulfill for obfuscation and how it must be used properly?

This guideline says that I have to submit my coins to mixer in parts

  if you want avoid potential metadata analysis correlation then you should break up your transactions into smaller, randomly determined amounts.

Is it the only thing that I must care about? What is the point of that? If investigators can trace individual amount then how can splitting your amount into subamounts obfuscate anything? Does it mean that you should prevent re-uniting of the amounts?


texts:
I'm sorry if I ask a stupid question. Bitcoin network was conceived by Satoshi Nakamoto as a decentralized network, but now we are seeing the full centralization of nodes in the United States.
The user lacks motivation for hosting the full node as it requires financial costs but it does not pay off.
I have a question. Does the bitcoin network protocol display address when requesting a useragent. Now we can see only the version and ip address. To anyone could donate a certain amount of coins for those who start a full node in the network.
The ideal option proposed by the bitcoin core developer Jeff Garzik  would be to make a commission for that unit is now fully take miners to share with all the owners of the full nodes.
Sorry for my English.


texts: How to get legacy address and private key from Segwit P2SH address?

texts: I have a Segwit P2SH address (starting with 3...) with the corresponding private key and need to obtain the legacy address (starting with 1...) and the private key. Is this possible?


texts:
I've seen this graph pop up around the interwebs, but never with an explicit explanation:

http://blockchain.info/charts/network-deficit

My question is how is this metric generated? Is it a comparison of the power and hardware costs versus returns?


texts: How are the transactions going to be verified after all BTC blocks are found?

texts:
If I understood correctly the current transactions are included in the generation of the next block, thus these transactions get verified.
But what happens when all 21 million bitcoins are already mined? When there is no block to be found anymore? How will then the transactions be verified? Will BTC simply die?
Edit: My question is not about mining decline, my question is how do the future transactions are going to be verified in the case where all the blocks are found.


texts: how do you transfer your Bitcoin core wallet while syncing?

texts: I would like to transfer my btc wallet to an electrum wallet. Syncing is taking to long.


texts: bitcoin compile error on CentOS 6.6: ‘SIZE_MAX’ was not declared in this scope

texts:
I am trying to run a bitcoind instance (branch 0.9 from git repository) on CentOS 6.6 following this guide but I get this error when building LevelDB:

Building LevelDB ...
make[3]: Entering directory `/home/bitcoind/bitcoind/downloads/bitcoin/src/leveldb'
g++ -I. -I./include -fno-builtin-memcmp -pthread -DOS_LINUX -DLEVELDB_PLATFORM_POSIX -g -O2 -Wall -Wextra -Wformat -Wformat-security -Wno-unused-parameter  -Wstack-protector -fstack-protector-all -fPIE -fvisibility=hidden -I/home/bitcoind/bitcoind/deps/include -DBOOST_SPIRIT_THREADSAFE -DHAVE_BUILD_INFO -D__STDC_FORMAT_MACROS  -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -c helpers/memenv/memenv.cc -o helpers/memenv/memenv.o
helpers/memenv/memenv.cc: In member function ‘leveldb::Status leveldb::<unnamed>::FileState::Read(uint64_t, size_t, leveldb::Slice*, char*) const’:
helpers/memenv/memenv.cc:65: error: ‘SIZE_MAX’ was not declared in this scope
make[3]: *** [helpers/memenv/memenv.o] Error 1
make[3]: Leaving directory `/home/bitcoind/bitcoind/downloads/bitcoin/src/leveldb'
make[2]: *** [leveldb/libmemenv.a] Error 2
make[2]: Leaving directory `/home/bitcoind/bitcoind/downloads/bitcoin/src'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/home/bitcoind/bitcoind/downloads/bitcoin/src'
make: *** [all-recursive] Error 1

gcc version: gcc version 4.4.7 20120313 (Red Hat 4.4.7-11) (GCC)

Here is the a pastebin with the end of the compiling output.

Anyone have some idea on how to workaround it?


texts: How can a miner know how many blocks mined by him?

texts:
I am working on an altcoin based on bitcoin-core, version 0.12.1 (this version including setgenerate).
Is their an option for a miner to know (using bitcoin-cli) how many blocks mined by him (after setgenerate was set to true), had been accepted by the network and had been inserted to the blockchain?


texts:
I have found many APIs and databases that exist for historical Bitcoin prices but they will only give you data for daily intervals or tick data.

Is there an API / database that exists that will allow a query for data by interval?

Example:
Query the last 500 closes for 5 minute intervals or query OHLC data?


texts: how to generate a bitcoin address for each user that registers

texts: I'm working on a marketplace type website and i want a bitcoin address to be generated for each user that registers an account. this needs to be done in php with no javascript


texts: Could I theoretically mine a block faster than 10 minutes?

texts: I have been reading a lot about this 10 minute block in the Bitcoin network.  I'm slightly confused because I thought mining was a somewhat random process, mostly based on how powerful your mining facilities are.  So if I had a quantum computer and could really churn through calculations, couldn't I mine a block faster than 10 minutes?  Or is there something in the network taht would prevent me from submitting my mined block until 10 minutes had passed since the last mined block?


texts: How is the solution hash in a block generated?

texts: For example, in the Genesis block in Bitcoin, from which values was the solution hash "000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f" derived from? I understand that the nonce is applied to something to get the solution, but I can't seem to find what those values are.


texts: and(older(10),pk(A)) malleable if top-level, can it be top-level? EDIT: not malleable, was mistaken

texts:
$ ./miniscript

and(older(10),pk(A))
X    110.0000000000    37 and_v(v:pk(A),older(10)) and(older(10),pk(A))

and_v(v:pk(A),older(10))
      1 scriptlen=37 maxops=2 type=B safe=yes nonmal=yes dissat=no input=1n output=nonzero miniscript=and_v(v:pk(A),older(10))
<A> OP_CHECKSIGVERIFY 10 OP_CHECKSEQUENCEVERIFY

(the last line shows the compiled script because I added printf("%s", Disassemble(ret->ToScript(COMPILER_CTX)).c_str()); to the command line-based tool output)
AFAICT nothing says that this cannot be top-level (but I may be missing something). It also says nonmal=yes, that this is not malleable.
The witness that is needed for this script to be successfully executed in the spending check is [<A_signature>, <any-nonzero>], and of course the CHECKSEQUENCEVERIFY condition must pass. The CHECKSIGVERIFY will consume <A_signature>, and then <any-nonzero> will be checked as the sole item on the stack, that indicates success (after CastToBool())
But <any-nonzero> can be just that, anything, and thus malleable.
What am I missing ?


texts: Can the fee produced by estimatefee be artificially manipulated?

texts: Could a miner who wanted more transaction fees manipulate the fee produced by estimatefee? If so, what percentage of hashpower would it take, and how long would you need it?


texts: Will my bitcoin wallet take prohibitively long to sync as daily transaction volumes grow?

texts:
I'm using Bitcoin-qt on Mac and it's been a few weeks since I last fired it up, so it's doing a sync. I've waited a few hours now, despite being on powerful hardware and a fibre connection to the web.

If I understand it correctly, the sync involves some processing for every Bitcoin transaction performed globally. In the bright future of Bitcoin, when people are buying Mars bars with them, won't the sync be prohibitively slow due to sheer volume?

Or are we hoping Moore's law will offset this growth?


texts: At which point do blocks get validated in the mining process?

texts:
I'm trying to understand how mining works and I'm stuck on the part about validating blocks and adding them to the blockchain.

When a miner finds a solution to a block, he shares it with the network, where other miners validate his new block by checking if the hash of the block (using the found nonce) is smaller than the target, right?

At which point does the validation of the block happen and how many users do have to validate the block so it gets appended to the blockchain?

Does this happen before a miner creates a new block? So basically he'd take a new block in the network, validate it, if it's okay, he takes that one as his "previous block" reference?


texts: How to use python reference for encoding a bech32 address?

texts:
Could someone provide an example of how to use the python reference implementation for generating a bech32 address?

For example, generating a mainnet bech32 address for this scriptPubKey: "0014751e76e8199196d454941c45d1b3a323f1433bd6"


texts: I sent my bitcoins from LocalBTC to a unsynced bitcoin wallet program, the bitcoins are not showing up. How do i get them back?

texts: I sent bitcoins from localbtc wallet to a unsynced program, it says 0 in the balance of the program and I really want them back.


texts: How do I get my encrypted private key converted?

texts:
"addr":              "typicalbitcoinaddress",
"compressed":        true,
"encrypted_privkey": "this  is my private key that is 96 characters long",
"label":             "Wallet",
"pubkey":            "Public key of the address",
"salt":              "random small set of digits not sure what this is"

I dont know how to convert my private key that is under "encrypted_privkey" (96 characters long) (Not sure what it is encrypted to) to a Wallet Import Format like to import it into blockchain.info....Any help on the process to convert this to a WIF private key would be greatly appreciated, I am unable to provide the private key of course...


texts: How to generate recovery phrase from private key

texts:
I created a brain wallet with a non standard phrase.

So I have that, the private and public keys.

Now this wallet app wants a 12 word recovery phrase to set up the wallet.

How can I convert what I have into a 12-word phrase that it can use?


texts:
I mean no disrespect to Gavin Andresen whatsoever. I think someone needs to be at the head of the project and Satoshi has stepped down / disappeared / gone back to the NSA / returned to his home planet / choose your conspiracy theory.

But why Gavin? What's the succession plan? What if Gavin gets tired of the project and chooses not to work on it any more? There certainly are core contributors, but exactly how is the "organization" set up? I know there's no actual "organization", but what I mean is the people in charge of the direction of the Bitcoin project.


texts: How to spend bitcoins From Account and specify Fee

texts:
I am writing an application that uses bitcoin wallet accounts to specify what addresses belong to what user. I have been reading the documentation trying to find a way to spend Bitcoins specifying the account from, address to, and miners fee.

After reading the documentation, I think that is impossible, because there are only two ways:

The first one is using sendFrom, but you can't set the fee with this command. You could use settxfee but that is a changing number depending on the Kb's of the tx.
The second one is using CreateRawTransaction and SendRawTransaction, but in order to specify the inputs, there is no way to get the inputs, other than calling listunspent, but that returns the inputs for all wallets, and there is no way to tell that command to only return the unspent inputs for a specific account.

Is there really no way to send bitcoins from account specifying the fee?


texts: How much does it cost to buy and sell bitcoins?

texts:
I'm a newbie.

Lets say I see the btc usd exchange graphs and see that it has tripled in the last month and I decide to put $5k in hoping it will grow.

What is the least amount of USD I could spend to buy $5k and sell $5k on a moment's notice whenever I feel like it?


texts: Optimizing fee payment for speed or zero fees/privacy? (Clients vs. e-wallets)

texts:
As far as I understand the more fees you pay, the faster the delivery. What I don't understand is fees are given to kilobytes of data, not amount of money.

Maybe here would come handy a little deeper basic understanding how bitcoin works behind the scenes, maybe I should read this book?

I don't know, but the bigger the money the bigger the block size? Or the newer the money the bigger the block size? Or a little bit of both? As the miner solve more and more complex calculation problems(?). And the older the bitcoin block, the cheaper the transfer, regardless how big the amount is?

Consider 2 cases:

1st, you want to optimize for lowest or zero fees: time is not an issue. In this case as I understand bitcoins are transferred in chunks to save on fees. Does it also increase you privacy as well? How much time it takes to transfer a quadrillion dollars (or a little less), and what is the absolute minimum fee for such a large transfer?

2nd, you need instant delivery. I'm not sure about the fee structure (does it depend on the client or wallet you use?) but is it a fixed or variable % or a fixed amount per transaction? In the Qt client you can set an amount for fees but how do you calculate to spend the absolute minimum fees for an instant delivery? That would be just optimal, right?

As e-wallets use a share address, transferring funds in between bitcoin addresses of the same e-wallet should be free, and instantaneous, right? Instawallet?

Do I have the choice if I want to optimize for speed or costs (and maybe privacy?) with the various e-wallet providers? Let's say I want to spend instantaneously from an e-Wallet BTC 1 but I want to know beforehand how much I should transfer to that wallet in advance (slow transfer, zero fees) to include the appropriate (fast) fees.


texts: How is a node in the middle prohibited from keeping the money in a routed Payment in Lightning network?

texts:
It is my understanding that Lightning is to scale with users having only few payment channels by leveraging the six degrees of separation theory to facilitate payment routing. I understand how onion routing is employed to obfuscate origin and target of the payment.

I have read claims that it is also not possible for a node in the middle to receive but not forward the payment. This appears to be implemented by having either all hops of the payment execute at once, or none at all.

How can it be assured that the whole payment chain executes the payment at once?


texts: Bitcoin.org developer reference outdated?

texts:
i just can't understand if bitcoin.org developer reference is outdated or not. for example here (https://bitcoin.org/en/developer-reference#raw-transaction-format) we can see: "As of Bitcoin Core 0.9.3 (October 2014), all transactions use the version 1 format described below. (Note: transactions in the block chain are allowed to list a higher version number to permit soft forks, but they are treated as version 1 transactions by current software.)" it's right or it's an old reality?
or here (https://bitcoin.org/en/developer-reference#serialized-blocks) we can read on the first 2 line that blocks must be serialized under 1MB size or less but i know on the current version blocks can be up to 2MB so i can't understand which one is the right answer. Thanks for the help


texts:
https://blockchain.info/unconfirmed-transactions?format=json

I have been given an api key, I would like to call the above url every second to count the number of tx in real-time.

I don't think that this though is the best way to do this as the data might be delayed by the response time and I don't like the idea of calling them that often (I would count that as sort-of abuse of service, though I don't know for sure). Also in a call I would have to filter out any tx with the same id that may have been listed in the previous call.

I would prefer to get a list showing all unconfirmed, and to not miss any at all, to see them as they happen.

I was looking at the bitcoind rpc call 'listtransactions'. I think that this would let me count quicker but, I would like to know if there is a way/api that will push me the world wide unconfirmed tx as they happen (so that I am always 100% accurate to count the real time number of transactions world wide).

Note: I only need to count the precise 'number of'.


texts:
I just started learning about bitcoin scripting and wonder:

what if the timelock in CLTV is in the past?
what if the timelock in nLocktime is equal to 500.000?


texts: Can someone help me find the private key for my bitcoin wallet?

texts: I have a Bitcoin Wallet on Blockchain and i have a imported wallet there where my bitcoin is stuck please help.


texts: Why do you have to search for TXIDs in little-endian?

texts:
I understand that when you double-sha256 some transaction data, it will give you the TXID for that transaction. This can then be used in future transaction data when you want to reference an existing transaction.

However, if you want to search for a TXID using bitcoin-cli or a blockexplorer, you have to convert this TXID to little-endian.

TXID (original):  B0570984EA35E417A20327D72414CDA0EB8200418772FA3E1A28D76EF4977CF2
TXID (searching): F27C97F46ED7281A3EFA7287410082EBA0CD1424D72703A217E435EA840957B0

What's the reason for this?


texts: What prevents similar time-warp attacks in Bitcoin as happened to Verge?

texts:
Right now (may 2018), Verge (an altcoin with proof of work)  was attacked by time-warp attack. More can be read here

https://blog.theabacus.io/the-verge-hack-explained-7942f63a3017

What exactly prevents from similar attack to happen to Bitcoin?

Verge has different hash logic (more frequent retarget, more concurrent hash algorithms), but the logic of the attack should, in my reading, apply also to bitcoin.

Since it did never happen in Bitcoin, I probably missed something. How is Verge different from Bitcoin that this happened in Verge, but not in bitcoin?


texts: Gridseed not mining bitcoin - no shares accepted

texts:
So I have had my Gridseed (5 chips) for about a week now, and still couldn't mine any Bitcoin, only Scrypt.

I am currently only able to mine with minerd, using Scrypt, and I am on a Mac.
I tried to mine Bitcoin using cgminer, bfgminer, minerd (versions from MacMiner and others on the internet), tried to compile, nothings seems to work.

Problem

With cgminer I can see the hashrate (~11Gh/s) but no share is accepted.
With bfgminer it just wont recognize the grid
With minerd it keeps trying and trying, and does nothing.

Looks like cgminer is my best shot, but no share is accepted.

I tried on a Windows VM (virtualbox), same outcome!
I have looked all over the internet (Gridseed-Help, Cryptomining-blog, GridSeed-Guide on BitcoinTalk, and off course Mac-Mining-Guide)

Does anyone have any input on here?


texts: Get the number of confirmations for an external address

texts:
I'm building an application that tracks transactions between two points for multiple currencies, currently:
BTC, BQC, BTB, FTC, LTC, NMC, NVC, PPC, TRC, WDC & YAC.

I need a way to check the number of confirmations for the latest transaction to a list of external addresses.  For BTC i discovered that i could do this (in a somewhat round about way) like so:
At start get the balance: http://blockexplorer.com/q/getreceivedbyaddress/ADDRESS/0
Then later i can check that again, specifying 1 confirmations.
/q/getreceivedbyaddress/ADDRESS/1
and see if the balance has increased from the start point, if it has, i know a transaction that is 1 confirmation in has occured. then i can check:
/q/getreceivedbyaddress/ADDRESS/2 and so on and so forth.

This works fine.  But for all the other coins there is no blockexplorer.com, but there is what is most commonly used, bitcoin ABE.

In bitcoin abe you can do a similar call, for example:
http://bbq.cryptocoinexplorer.com/chain/BBQCoin/q/getreceivedbyaddress/ADDRESS
but from what i can tell bitcoin abe does not support the /N parameter at the end to specify the number of confirmations.

So now i am stuck.  I looked into running local instances of all the different coin deamons like bitcoind. But, although bitcoind has getreceivedbyaddress, bitcoind does not support this for external addresses.  Since i do not know the private keys of these addresses i cannot add them locally, and so bitcoind does not work for my purposes.

Since all the other altcoin clients are based on bitcoind, they all share the same problem as well.

Any help is greatly appreciated!


texts: What does the curve used in Bitcoin, secp256k1, look like?

texts:
I'm reading up on ECC curves and on many of them I see an illustration that looks like this

What does the comparable curve in Bitcoin look like, or are all curves generally the same?


texts:
I got vps with ubuntu 18.04 with ssh access and bitoind set up on it. This is my bitcoin.conf file:

testnet=1
prune=35840
maxconnections=12
muxuploadtarget=20
daemon=1
server=1
rpcclienttimeout=5000
rpcuser=[usr]
rpcpassword=[psw]
rpcallowip=0.0.0.0/0

This is my rpc call:

curl --data '{"jsonrpc":"2.0","method":"getwalletinfo","params":[]}' http://[usr]:[psw]@localhost:18332

When it given in vps terminal, that return json response just like it meant to be, but when i got this request on another machine:

curl --data '{"jsonrpc":"2.0","method":"getwalletinfo","params":[]}' http://[usr]:[psw]@[myvpsip]:18332

terminal returns:

curl: (7) Failed to connect to [myvpsip]: Connection refused

This is my result for "sudo netstat -tuwpln" on vps, pasted results only with bitcoind:
:

Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
tcp        0      0 127.0.0.1:18332         0.0.0.0:*               LISTEN      2027/bitcoind
tcp        0      0 0.0.0.0:18333           0.0.0.0:*               LISTEN      2027/bitcoind
tcp6       0      0 ::1:18332               :::*                    LISTEN      2027/bitcoind
tcp6       0      0 :::18333                :::*                    LISTEN      2027/bitcoind

Already checked firewall and it has Status: inactive. Iptables also empty. Got connection over ssh, so server is able. Also pinged well. I still think that problem is in bitcoin.conf but don't know exactly where is it. Can anyone help solving this problem? I would be really greatful

P.S. Writing script on python and one part of it is bitcoin payments, so really need solution for this. If there easier way for payments would like to familirize.


texts: How can I sign a bitcoin address that is on a paper wallet?

texts:
I have a bitcoin address that shows I held the BTC prior to December 2019.  I need to verify this but as the address refers to a paper wallet I don't seem to be able to do so.   If I move the coin to a hardware/software wallet I can verify BUT I will have created a new address that doesn't meet the criteria in that case.
Is there a way to sign a message with my paper based bitcoin address?  Or import the paper wallet into something that can sign messages?


texts: Is it safe to connect multiple alternative crypto currency clients to the same TOR socks port?

texts:
Or should I create multiple TOR socks ports and use one for each client?

I plan on running bitcoind, namecoind, litecoind, etc... all on the same ubuntu machine running under different users but all going though the same TOR connection.


texts:
I recently came across Steemit, a Reddit-esque platform which seems to be running on the Steem blockchain. It looks like it is paying its users to post and curate content. However, it looks rather leery that essentially a lengthy blog post could have a pending payout of over $3900. Even taking into account the exchange rate of about 0.25 USD/Steem, that is a good pay for writing articles.

So I wonder - what's the catch? What is Steem and Steemit all about? Is the platform really paying people hundreds of dollars to post articles, or is there something fishy going on?


texts: Generate new .onion address for bitcoind over tor

texts:
Been following this guide just to tinker around with bitcoind over tor. According to the guide, when bitcoind controls the tor daemon using controlport=9051 whenever you restart bitcoind tor should generate a new .onion address. This is not happening. If I restart bitcoind, tor or both, it always uses the same old .onion address. A fully system restart doesn't work either.

how do I generate a new .onion address?

Note: I am NOT using /blah/var/hidden_service and cannot just delete the private key in that folder. When using controlport there doesn't seem to be a private key anywhere. Or is there?


texts: Where is my bitcoin balance stored in the blockchain?

texts:
This is possibly a duplicate but, since I am a Bitcoin dummy I cannot find it.

Anyhow; as I understand (and I will make some assumptions here), a block in the blockchain contains one or more transactions.

Transactions are typically bits of information which contains delta's, I mean e.g.: Alice transfers 2 bitcoins to Bert.

So, to determine or verify my bitcoin balance (in order to make a valid transaction), does the whole chain needs to be analysed? If so, is this optimized in any way?

Or am I completely off track here?


texts: How many channels can I create from a Lightning Node?

texts:
I am new to the Lightning Network / Bitcoin and am trying to get an understanding as to how it functions.

Basically, suppose I have a Lightning Node (created with "lightningd"). It is my understanding that this is a daemon that starts at a certain port: 9735. On my picture, it is the box with "My Node".

Question 1: is there only one wallet inside of this node? If so, is there a way to have additional wallets inside of the same node? Does one use the wallet address when one receives/sends funds (kind of like the way the Bitcoin address to receive/send funds)?

Question 2: Is there a limit to the number of Channels I can create from "My Node"?

Suppose I have some relatives that do not use Smartphones but want to send/receive money over the network. They are represented in my picture with "Grandma", "Grandpa", "Mom", "Dad", and "Aunt Wilma".

Since they are older, they do not know much about computers, I am running their LN Nodes for them on my own computer.

Question 3: In this case, would I need 6 extra Lightning Network daemons ("lightningd") on my computer?  If so, then would each daemon have to assign a different port address? Is there be a better way to do this?

TIA


texts: We have a ATM Network and we want to sell and buy BTC or ETH on our ATMs, using our own switch. How can we do it?


texts: Security bridge on bitcoin-qt walletpassphrase

texts:
Is it safe to use walletpassphrase with bitcoin-qt rpc call ?
I can think of a security problem, suppose hacker was able to insert some kind of program that call each second to the wallet with sendToAddress and the hacker bitcoin address, now he will get a lock response each time until the call will execute on the timespan the wallet is unlocked. is it possible ?


texts: When I use InstaWallet.org, do I get my own Bitcoin address?

texts:
InstaWallet is an online Bitcoin wallet service.  When I visit it for the first time, it generates a Bitcoin address that I can use to deposit to.

I'm wondering whether that address is only ever used for my account, or whether all the coins that InstaWallet receive end up in a single large wallet.

If it's only ever used for my account, I should be able to use blockexplorer to monitor my balance.  That's the case with MyWallet, since they don't even have access to the address' private key.
On the other hand, if everything goes into a single wallet, it's possible that other users' withdrawals may be paid with funds from my deposit address.  That's what happens at MtGox and other exchanges.

So which is it?


texts: Just changing the nonce of a block to be mined is not enough to cover enough hashes to solve it. What are the most common tricks used by the mining software and pools in order to create enough getwork variants to solve the block? Which can be done only by the pool, and which can be performed by the miner?


texts: I bought 1 bitcoin and sold part of it to make cash from time to time. How will tax on this income be calculated?


texts: How to receive payments online to single address per user in scalable way?

texts:
Suppose we are building online casino/market and want to receive payments.

To be scalable, safe and have good user experience, we:

cannot generate new address for every single payment. Having single deposit address is a lot easier. Also users always can deposit to old address by mitake even if generated new address.
cannot check listreceivedbyaddress because regulary checking hundreds of thausands of addresses is not scalable. Also large RPC output when single user make thousand of deposits.
we should do not rely on external services online blockchain API.

We absolutely cannot use any RPC call that will list complete and growing list of transactions like all transactions for wallet or all transactions for address.

So, the most sensible way should be checking by listsinceblock to parse all transactions "per analysed block" and joining to user balances by destination address - incrase user amount in our online service and mark this payment as "completed" to not count it second time. Simplest way of marking this transaction as "already resolved" is to store its ID as "already used" in same SQL transaction that incrases user balance.

But I heard that it is possible to change transaction id in block chain, so is such solution safe?

How can I use RPC calls to receive payments block after block and which data can I use to mark payment as resolved to be safe from duplicated deposits on single payment?

TL;DR how "big players" like Cryptsy do receive payments?


texts: Can I set up cgminer to mine in different pools, by a defined ratio?

texts:
I'm mining in different pools, one is main and I would like to dedicate 80% off the time spent mining on it, but I'm also mining in another and would like to dedicate 20% on that. I know you can set up the config as following:

"pools" : [
    {
        "url" : "http://pool1",
        "user" : "user1",
        "pass" : "123"
    },
    {
        "url" : "http://pool2",
        "user" : "user2",
        "pass" : "123"
    }
]

But is there a way you could define a 80/20 // 70/30 mining setup between the pools so that it mines the first pool for 19 hours, then the second pool for 5 hours (or days)


texts: Best way to anonymize bitcoin transactions?

texts:
https://en.bitcoin.it/wiki/Mixing_service

How do sites like this work? "Mixing services". I know it can be broken and traced back with coinsuduko but how exactly does it wash your coins. I doubt they just wait for somebody else to send in enough funds to reimburse with new coins, how would they go about doing it? Do they send the 1 BTC or whatever amount through 50 or so different wallets in different amounts on a bitcoind and then return the 1 BTC to your set wallet? I've heard of coinjoin, how does it work?

If I was going to send 1 bitcoin from one wallet to another from my website but have the bitcoins "washed" what would I need to do to keep the transactions hidden or at least "Mixed" so it would be harder for the bitcoin receiver to figure out what address exactly sent the coins.

Here is another example of open source coin washing blockchain.info uses:
https://github.com/blockchain/Sharedcoin is all this javascript on user side really necessary (speaking from using their setup sharedcoin.com, not reading over the source which is also javascript.)

Thanks.


texts: how to spend an utxo when the corresponding scriptsig is longer than 256 bytes?

texts: I am trying to spend an utxo sent to a p2sh address. The scriptsig (including the redeem script) is longer than 256 bytes. When the transaction is serialized there is only one byte to indicate the size of the scriptsig. How should I do? Thanks by advance.


texts: Now we know how to redeem standard P2SH and P2PK transactions, but now since witness scripts are no longer included in transactions, how would script evaluation work under segregated witnesses?


texts: I hope I ask in the right place. Since both are have same source. So, what's going on with BCH? Why before the hard fork the price is sky rocketing but after the fork. It sink like a sinking boat?


texts:
I have an HW.1 I had lost and finally found.  I tried to access but the new ledger software does not work.  i tried with electrum, but have managed to lock myself out of pin attempts.
What can I do to recover my bitcoin from this device?  I have searched and can't seem to find much on it.


texts: How can I set the port of bitcoind to run Armory through Tor?

texts:
I'm trying to set up Armory with Tor by directing all Armory communications to port 9150 which is the one that I have been told my Tor browser uses.

Before I start Armory or the Tor Browser, I activate bitcoind with the terminal command 'bitcoind -proxy=127.0.0.1:9150'. But when I then start Armory, it tells me that I must shut down this instance of the program and allow Armory to start it instead. OK, but there seems to be no way to inject the command line switches into the version Armory starts.

If I disable the the Armory checkbox 'Let Armory run bitcoind in the background' then it does not give me that objection message but instead never goes online even if I have started bitcoind manually.

There is another thread on this subject but, since I am new here, I don't know if I can just attach a new question to an old thread or must post a new one.  So, I decided to post a new one, sorry if that is not the correct procedure.

And, to address the issue of a Wiki brought up in the older thread, the problem seems to keep changing because the functions of Armory and Tor keep changing. For instance, I can't run Vidalia on my system because I run Ubuntu 12.04 and Vidalia is not available for that version. I must run the Tor browser instead to get activation of the Tor network. So perhaps a Wiki would be good.


texts: On Blockchain.info, how many addresses can I pass into one API call?

texts:
Most of the Blockchain.info API calls (eg Unspent outputs) allow you to specify multiple addresses in one call separated by "|". Is there a limit to how many addresses I can pass in?

If I pass in 1000 addresses, does it still count as one API call toward my rate limits?


texts:
My problem is that I can not do any transactions at all because of an error.

BitcoindException(super=com.neemre.btcdcli4j.core.BitcoindException: Error #-26: 66: mempool min fee not met, code=-26).

I set the standard (not customized) transaction fee to about $12 now, but the error still appears. What is the way out of the situation?


texts:
First, some background.

1. There are some coordinates x,y satisfying y^2(mod p)=x^3+7(mod p) on the Secp256k1 curve that do not correspond to a valid Bitcoin uncompressed publicKey of the form 04[x,y].

We can prove 1 using the random_point() function in Sage with unknown generator underE=EllipticCurve(GF(modi), [0,7]). If we get lucky, after a few trials Sage returns a point such as Q.

   Q=E.random_point()

   Q
   (B8F0170E293FCC9291BEE2665E9CA9B25D3B11810ED68D9EA0CB440D7064E4DA :
    691AA44502212591132AA6F27582B78F9976998DE355C4EE5960DB05AC0A2A3 : 1)

Now we have:

   Qx=B8F0170E293FCC9291BEE2665E9CA9B25D3B11810ED68D9EA0CB440D7064E4DA
   Qy=691AA44502212591132AA6F27582B78F9976998DE355C4EE5960DB05AC0A2A3

We verify that Qy^2(mod p) = Qx^3+7 (mod p) is satisfied so we confirm that Q is a point on the Secp256k1 curve.

Next, we try to validate Q as an uncompressed Bitcoin publicKey:

04B8F0170E293FCC9291BEE2665E9CA9B25D3B11810ED68D9EA0CB440D7064E4DA691AA44502212591132AA6F27582B78F9976998DE355C4EE5960DB05AC0A2A3

We get: Q is not a valid publicKey.

Yet, checking the validity of the mirrored point -Q, returns a valid publicKey:

   -Qx=B8F0170E293FCC9291BEE2665E9CA9B25D3B11810ED68D9EA0CB440D7064E4DA
   -Qy=F96E55BBAFDDEDA6EECD5590D8A7D4870668966721CAA3B11A69F24EA53F598C

Valid publicKey for -Q:

04B8F0170E293FCC9291BEE2665E9CA9B25D3B11810ED68D9EA0CB440D7064E4DAF96E55BBAFDDEDA6EECD5590D8A7D4870668966721CAA3B11A69F24EA53F598C

Valid publicKey for -Q (hashed):

1A2gaiiKy91Pmx8EUcbT4Hd6JFZ3sQvUhM

Question:

Why not every [x,y] coordinate on the Secp256k1 curve corresponds to a valid uncompressed publicKey?

Note:

In this question, by validity I mean a set of EC coordinates (x,y) that can be hashed into a bitcoin uncompressed address. I am specifying uncompressed for obvious reasons. My question is detailed enough I hope to show that it's not referring to compressed Bitcoin addresses.


texts: Bitcoin Core HD Wallet v0.13.2 missing confirmed incoming transaction

texts:
I made a transaction from my android wallet to my bitcoin core HD wallet (v0.13.2). At the time of writing, the transaction has 5 confirmations, both according to the android wallet and blockchain.info. However, my bitcoin core wallet fails to pick up the transaction, despite showing the right blockchain height.

The recipient address was generated by bitcoin-qt, hence it does belong to my HD wallet. Furthemore, I am able to sign a message with this address on bitcoin-qt (indicating I own the private key) and successfully verify the signature. In fact, in the course of my investigation, I had the unpleasant surprise of realizing that this address had already been generated in the past and I had already sent bitcoin to it as can be seen here. (This seems related to the issue reported in this post but is no longer the most pressing matter now). The older transaction using this address is part of my bitcoin-qt transaction log. So there can be no doubt the recipient address does belong to my bitcoin core HD wallet.

I am reluctant to attempt replicating the issue I have just described with another trial transaction. However, as this is probably relevant, I will explain what I did prior to this happening: 1. I made a copy of wallet.dat and removed the file from ~/.bitcoin (so running bitcoind or bitcoin-qt would automatically generate a new emptywallet.dat). 2. prior to the transaction I restored my copy of wallet.dat into ~/.bitcoin and started bitcoin-qt. 3. I asked bitcoin-qt for a new address and had my android wallet carry out the transaction. 4. I then shredded and removed wallet.dat and restarted bitcoind for a while. 5. When seeing the transaction had been confirmed, I re-instated my copy of wallet.dat into ~/.bitcoin with the intention of performing another transaction. 6. I then re-started bitcoin-qt which fails to pick up the latest transaction.

Note that this process of mine of shredding wallet.dat from ~/.bitcoin (while a copy of the file exists in a more secure location) is something I have just decided to do, as a way of making it harder for any potential hacker to spend the coins on this wallet.

So my bitcoin core wallet is obviously confused. Is there anything I can do to set it straight?

EDIT: When I re-instated my wallet.datinto ~/.bitcoin I am guessing a re-scan was not triggered for some reason. I shredded again my current wallet.dat and re-instated my (older) backup: this time a re-scan was triggered and the missing transaction was picked up.

So this issue is resolved as far as I can see it (albeit with the unease of not knowing why).


texts: I am new to Bitcoin and recently have invested in bitcoins. I came across Nicehash when I was planning to get into Bitcoin mining. I understand that Nicehash gives you an option to rent hash power for mining. But what I don't understand is the pool option in it. What exactly are the pools in Nicehash and how do I create a pool account or join a pool or something? I don't want to spend any money on Nicehash without understanding what exactly it is used for.


texts: Transaction to Coinbase not showing up in account

texts:
On 26th and 31st of January I transferred each 1 BTC (total of 2 BTC) from my Blockchain wallet to my Coinbase wallet. On the Blockchain site they show up as confirmed transfers. However, on the  Coinbase page they do not show up in my wallet. A 0.10 BTC transfer in December showed up right away.

There are phone numbers and e-mail addresses on the Blockchain site, I can't find anything on the Coinbase site.

Is there any way to reach the Coinbase site to inquire about the transfer?


texts: What is the best way to get notified of new payments received

texts:
Using the daemon and not a 3rd party pinging service, what is the best way to get notified of new payments?
Do we need to constantly poll the server?


texts: How are segwit block transactions verified?

texts: From my understanding, segwit blocks send transaction information without the witness, which includes the signature. I thought nodes needed the signature to verify the transactions?


texts: History of cold boot attacks on Proof-of-Stake miners

texts:
Have instances of theft due to cold boot attacks been recorded?  If so, is this a common problem?

If so, are miners installing memory encryption software like Trezor?


texts: How bitcoin application in production retrive UTXO's

texts:
AFIK, UTXO of an address cannot be retrieved using bitcoin-core, without importing the address in the wallet.

How are application in production able to get UTXO ?
Does all the application use Indexed database like Insight or Abe to get UTXO ?
Is there any way to get UTXO from bitcoin core without importing the address into the wallet?


texts: Bitcoin without mining - what needs to be implemented

texts:
I have read this related question - Bitcoin without mining and I am trying to understand the very basics of Bitcoin network and the blockchain.

I wonder, if we take the mining out of Bitcoin, what would we need to implement in order to make it a working system again.

So far, I am aware of these components that rely on mining:

new coin generation - without mining, we would need to implement a new way of introducing new coins to the system
bitcoin mining is used to create and validate blocks which contain transactions that are to be included in the immutable blockchain - so, without mining, we would need to create another system of creating new blocks that all the nodes will accept (i.e. consensus)

My questions are:

Is there anything else that would need to be done? In this question I assume everything else we would like to work like Bitcoin.
What are the alternatives of building blockchain? If we think about Bitcoin as a currency scheme only (and disregard other aspects of having blockchain) - do we really need a chain that stores all the history? Can't we just have accounts and their balances and update them? I.e. what are the other options of solving the double-spend problem besides having a full history in a chain.


texts:
Hypothetically...

A uses a desktop bitcoin client, who would like an overdraft facility.

B has lots of bitcoins and would like to offer that overdraft and charge interest on the overdrawn amount.

Can A just go into a negative balance with B's backing? If not, what would A and B need to change to achieve an overdraft or an aproximation of an overdraft?

(Note, an overdraft is different from a loan, but a loan might be used to approximate an overdraft if its automatic.)


texts: Do Full Nodes validate all transactions and make new blocks after all bitcoin are mined?

texts:
Do Full Nodes validate all transactions after all bitcoin are mined?
A fork of bitcoin core with all coins pre mined would be behaving in this way too I'd imagine..?
Also, would these nodes still create blocks of transactions, if so, why dont full nodes do this now? Is mining only a safety mechanism for a permissionless network?
See this quote at the link below:

Blockchain Validation vs Blockchain Consensus
It’s important to note that “validation” and “consensus” aren’t the same thing. A Blockchain Validator performs validation by verifying that transactions are legal (not malicious, double spends etc).
However, Consensus involves determining the ordering of events in the blockchain — and coming to agreement on that order.
Essentially, Consensus involves agreeing on the ordering of validated transactions.
The validation precedes the Consensus. We may very well have something that is “valid” that the network does not “agree” upon.

https://medium.com/@BitSongOfficial/blockchain-validation-vs-consensus-4adfce5ac030?_branch_match_id=601696356432534106


texts:
I have a fullnode without txindex.
Some transactions of mine related to my wallet are not being found by fullnode, only in blockchain.info.
My HD is around 130GB, and it's fully synced to the last block.
I would like to know, if using txindex = 1, will solve my problem with transactions that are not found.
Using txindex = 1 and -reindex, how long does it take to finish?
Fullnode will have to download again the 130GB? Will increase storage?

For exemple:
https://blockchain.info/pt/tx/1585045cf36e18829292eef72281c8a0a748488d960816437dbd0797d896adf9
This transaction send for 1BS3caAYJH5LTKprkbvhkSLVUhpa9QsvMp my wallet.

When i run bitcoin-cli getreceivedbyaddress 1BS3caAYJH5LTKprkbvhkSLVUhpa9QsvMp 0, result is 0.00000000
When i run bitcoin-cli gettransaction 1585045cf36e18829292eef72281c8a0a748488d960816437dbd0797d896adf9, resulti is error code: -5 error message: Invalid or non-wallet transaction id
How i solve it ?

Thank you.


texts: bitcoin listunspent showing an address which does not belong to my wallet

texts:
I use bitcoin listunspent to list unspent UTXO, but found one that doesn't match my addresses, so what's that address and where is it from ?

bitcoin-cli listunspent
[
  {
    "txid": "edc69b3fb53bd221129c4e0f115bdaa5227d01173a23aac2064fc29a78006714",
    "vout": 1,
    "address": "2MtkQ9MeXv9vKeFLuTPeEPfj5DQfWnL1jbw",
    "redeemScript": "0014e329000822d1b101d7940800ff2983aa54b33374",
    "scriptPubKey": "a914107caab5b5a035de348d22aa865d20db3fb1907987",
    "amount": 0.54856181,
    "confirmations": 92,
    "spendable": true,
    "solvable": true,
    "safe": true
  }
]


texts: If I am planning to accept bitcoins, does my client need to be running? Can I simply give out my public key and open the client later to receive? Does it depend on the client (I use MultiBit)? Furthermore, if I send bitcoins, do I need to keep the client open for the receiver to receive their payment, or are they all set to receive as soon as their balance (not available balance) goes up?


texts: Do you know any bash script or C simple program to generate btc and ltc addresses? I need to generate address while in recovery mode on osx or on a linux onthefly. But I cannot find such a thing on github: they're in python or never compiles or just do btc or ltc.


texts: Are blocks sent only after finding nonce?

texts: One of the concerns with increasing the block size is that it may get orphaned more often due to network latency in sending the big block. Why can't miners send the block without the nonce as soon as they start working on them. When they find the nonce, they can just send the nonce with block headers which will be quick. It will be also fast for other nodes to validate as they have to just check one hash with the nonce to know if the block is valid or not. They would have already validated the transactions before and merkleroot much before.


texts: error message : "com.googlebitcoin.core.ProtocolException:Peer does not have a copy of the block chain"?

texts:
I sent a Bitcoin yesterday at 8pm using Hive and this morning an error message popped up

com.googlebitcoin.core.ProtocolException:Peer does not have a copy of the block chain

Does it normally take this long for the transaction?  It still appears as pending in Hive.

To make matters worse the transaction is not found on blockchain.info.

Can someone help figure this out?


texts: sent bitcoin to bitcoin cash address on coinbase

texts: Accidently sent bitcoin from blockchain wallet to coinbase, but used a bitcoin cash address for the transfer, by mistake.  Can I fix this so I can get my bitcoin?  On my coinbase wallet,  i don't see the bitcoins anywhere.


texts: Who controls Solidcoin's special millionaire accounts?

texts:
Solidcoin takes the following approach to preventing the 51% attack:

As with existing cryptocurrencies, SolidCoin 2.0 stores transactions in a "block chain" which is essentially what it sounds like. Transactions go into a block, nodes do work on that block to verify it, and if the work is good enough they can submit it to the rest of the network. SolidCoin 2.0 then comes into action, every other block in the chain must be worked on by someone with at least a million (1,000,000) SolidCoins in an account.
One initial problem with this p2p security feature is SolidCoin only had 1.112 million coins prior to this security feature being implemented. To solve this, 10 accounts of 1.2 million were created in the genesis block. These are special accounts that cannot be spent on the network, effectively making them "Null accounts used for special purposes", until SolidCoin does have real millionaires.

So, who controls these ten special purpose accounts? And are they supposed to be disbanded when real millionaires come around?


texts: Why doesn't each node store only a portion of the blockchain?

texts: Why doesn't each node only store a portion of the blokchain instead of the entire blockchain? Is it possible and why is it possible or impossible?


texts: Is there a Bitcoin wallet app for Android which allows me to quickly generate say 50 addresses, label them and...

texts:
Is there a Bitcoin wallet app for Android which allows me to quickly generate say 50 addresses, label them and then export the whole list to a text file or copy/paste all at once (not one by one)?

I think the title says it all.

I want a bitcoin wallet app with these features:

-Should be possible to quickly generate 50 addresses or more and label them
-The list of addresses should be exportable to text file or possible to copy/paste all addresses at once as opposed to copying address by address.

Anyone knows of such an app and has a link?

Vesa


texts: Upper and lower bounds of the amount of bitcoins?

texts:
As far as I understand, the bitcoin has an upper limit of 21 Million possible coins. Thus, the price of 1 coin, can in theory climb and climb. However, on the other hand, it seems like the system can handle 10^(-8) of a bitcoin.

Is this observation correct?
Is it already possible to have transactions of fractions of bitcoins?
If (1) is true, how can this fact influence the bitcoin's rate? In some sense, it means that the limit on the number of units is somehow much higher then 21M. Or more generally, how should its rate be interpreted given the existence of such tiny fraction of the unit?


texts: How do i parse the zeroMQ messages in java?

texts:
This is the code that i have. I receive messages from the zeroMQ however a hashtx message for example looks like this --> "hashtx Ř�����v����|(8d �!��v��&�-�k�". Any help in turning that into a real hashtx is appreciated :)

public static void main(String[] args) {
    ZMQ.Context context = ZMQ.context(1);

    // Connect our subscriber socket
    ZMQ.Socket subscriber = context.socket(ZMQ.SUB);
    subscriber.connect("tcp://192.168.137.211:28332");

    subscriber.subscribe("rawblock".getBytes());
    subscriber.subscribe("hashblock".getBytes());
    subscriber.subscribe("rawtx".getBytes());
    subscriber.subscribe("hashtx".getBytes());

    while (!msg.equalsIgnoreCase("END")) {

        String printMe = new String(subscriber.recv());
        System.out.println(printMe);

    }

}


texts: How to transfer BTC from desktop wallet to mobile wallet (without fees), say using Electrum or Bitcoin Core

texts: I have both Bitcoin Core & Electrum wallets installed on both my desktop & mobile.  How do I transfer BTCs from respective desktop to mobile wallets (& vice-versa) directly (i.e., not thru the blockchain) to avoid fees?


texts: How does Coinmarketcap calculate volume?

texts: Does Coinmarketcap read all  trade history from the APIs of all exchanges and sums them up to calculate overall 24h volume? Or Does it retrieve it directly from specific coin's api?


texts: How do pools get the needed transaction information?

texts: How do the mining pools obtain the transaction information required to create a new block? Do they communicate with the network directly, or perhaps through a Bitcoin client, like bitcoind?


texts:
I'd like to create a Software as a Service (written in Python, so it would be nice to have good for this language) with some paid content in BTC.
Basically, I would like that users are able to pay:

Directly in BTC. I have identified Coinbase and Bitpay, but I would
also consider using a wallet on my own (in this case, I will use
bitcoinlib).

Through a "broker" with PayPal, Visa, etc. and I receive BTC.

I am interested to know your experiences/opinions and if you can give me some pointers.


texts:
I got the the new MB http://www.asrock.com/mb/Intel/H87M/?cat=Specifications which comes with Qualcomm Atheros AR8171 Lan, and unfortunately BAMT 1.2 does not have a driver for it included.

Does exists the way to install the missing driver, does the driver exists at all? I'm totally new to Linux and don't know even how to open command line in BAMT.

I use USB boot image from: https://litecointalk.org/index.php?topic=2924.0

If there no option to install the driver, can I use USB to LAN adapter without additional headaches, or I will need to install the driver to?


texts: Can an onlooker even learn anything interesting by de-anonymizing a transaction?

texts:
If people cannot see what exactly the items purchased are but they only see the transaction of funds in the blockchain, does anonymity therefore even matter?

Unless you get associated with criminals later if their address is seized and your transaction to them is viewable on the block chain?


texts: How to determine EUR (or USD) price from Poloniex Ticker?

texts:
Poloniex has for me a strange ticker content.

Rest API URL: https://poloniex.com/public?command=returnTicker

I have no problem with other plateforms to determine an immediate price, for example EUR / BTC price.

But with Poloniex, there is no EUR_BTC pair... only crypto to crypto pairs.

Example (actual BTC price = 1170€):

BTC_ETH
id  148
last    "0.07956500"
lowestAsk   "0.07977149"
highestBid  "0.07956501"
percentChange   "-0.00406771"
baseVolume  "2206.78596466"
quoteVolume "28048.32458745"
isFrozen    "0"
high24hr    "0.08127295"
low24hr "0.07676536"

With tickers, a volume is usally a Dollar amount... here, I don't know.

How to calculate a Euro or Dollar price with such info?


texts: If a miner is payed per block found, why not scrape the bottom of the barrel and full up blocks with 0 fee transactions? You would still be getting coins for blocks found just not the fees. The bonus would be no competition on finding blocks. Win/win for everyone...


texts: How to get the wallet address of my own LND node?

texts:
I have set up a lighting node using LND time ago, now I would like to send more BTC to it.

How can I get the wallet address of my LND node?


texts:
I've been reading about the working of LN. I had this interesting thought, what if we dont need the main blockchain and the miners to have a p2p cash system. Let me explain.

The difference between the current LN and what I thought is, people have channels only with the people they know and trust. There wont be any multisig wallet(may be set a limit for each channel based on their trust of the other person). And when they wanna close the channel, they transact in real life either with bitcoin or fiat (whatever unit they are using). Since it the people they trust there wont be any cheating problem.

This will be a completely p2p system. Would such system work? Am I missing anything?


texts: How do you sign transactions from a HD wallet?

texts:
I'm using the following tool to generate a HD wallet:
https://iancoleman.io/bip39/

However, it gives quite a few different private keys and I'm not sure which one is used to sign transactions with.

I'm using the bitcoinjs-lib to create an EC pair but I'm not sure how to go from the private keys generated to a hexidecimal string:

https://github.com/bitcoinjs/bitcoinjs-lib/blob/master/test/ecpair.js#L29

Thanks!


texts: Compiling Bitcoin Core 0.21.1 on Apple M1 architecture

texts:
I'd like to upgrade from 0.21.0 to 0.21.1 on Mac Mini (Big Sur 11.1), compiling from source. When trying to compile the dependencies by running 'make' in /depends subdirectory, I get the following error:
ERROR: Feature 'system-zlib' was enabled, but the pre-condition 'libs.zlib' failed. make: *** [/Users/xxx/bitcoin/depends/work/build/arm-apple-darwin20.2.0/qt/5.9.8-82a1b93ac0c/qtbase/.stamp_configured] Error 3
Any advice on how to solve this would be appreciated!


texts:
I have one very basic question,

I would like to know:

what programming languages are used to built bitcoin?


texts:
Its the hypothetical future and BTC2 is being designed. Everyone loves BTC2 and no-one wants the old BTC1 any more.

People who have BTC1 would be annoyed that their assets are suddently worth a lot less because there's no demand for their BTC1 any more, so the designers of BTC2 want to include a simple way to convert their BTC1 into BTC2.

For this to work, the BTC1 world would need a way for coins to be put beyond use within the BTC1 world, in a way that everyone can be reasonably sure that no-one can use the evaporated BTC1 assets any more.

Does such a mechanism exist? If not, could/should one be added?


texts: What's the most efficient way to create a raw transaction with a specific fee rate?

texts:
There seems to be a chicken and egg problem when it comes to creating a transaction that has a specific fee rate (sat/kW).
In order to set a specific fee rate, you need to know what the total weight of a transaction will be. But in order to calculate the total weight, you'd presumably need to have the complete transaction, including some kind of temporary value for the fee.
I can imagine there are some edge cases where the input only has enough to cover a small fee, meaning that setting a high fee would require adding another input to the tx, complicating the tx size estimation.
Are there any efficient solutions for this situation?


texts: Provide payment processing to my community

texts: I want to create a simple app to allow people accept Bitcoin in my community with low fees. I was thinking to build a full node on my server and made all of the transaction pass through it, do you think is a good idea or there is a better one?


texts: Help! Tried sending bitcoins to myself and they disappeared

texts:
I'm using the bitcoin-qt client on v0.8.1-beta on Mac OSX

I have 3 addresses.  I tried sending .01BTC from one address to another.

1K3BjT1y2X2v3PGhqHh33dRb6kVGdR5CBA ->  1MattHdtuFSof3ctrZhTGzsfQecQBso2nw

However!!! When I lookup the transaction ID: f638b5ecda8d8b0280a49f342e6cac13560917d5e678f1e3b9a7f35f69b15b97

I did sent the .01 to myself but it also sent
1.2594786 BTC -> 1Ypzoqn4BYSbgeqPJ3mSPdqBC8JGzgX4r

I have no idea what the 1Yp... address is!!

What happened!!!  Did I just loose $1000 ?

it did NOT prompt me about paying any transaction fees!!

I would greatly appreciate any help!

Update:
Yeah!!! I recovered my coins.   For whatever reason bitcoin-qt generated a new private key but didn't show ANY indication of this in the GUI.  This may be because it was backlogged by about 100 days in downloading transactions..  not sure.  but in any event LUCKILY i had been messing around with trying to migrate to multibit.. anyway i tried to export the private key and was successful:

walletpassphrase  120
dumporivkey 1Ypzoqn4BYSbgeqPJ3mSPdqBC8JGzgX4r

Then it worked !  it actually dumped the priv key and I was able to import into blockchain.info and get access again.  Not sure what happened but it was very unnerving...   again, the GUI does NOT show 1Ypzoqn4BYSbgeqPJ3mSPdqBC8JGzgX4r as one of my addresses...

Anyone care to explain what happened?

Source:


texts: I sent some Bitcoin to a Bitcoincash adress on Trezor and it doesn't show on my Bitcoin in Trezor, how can I get them back ?


texts: Unplugged Trezor when incoming transaction was unconfirmed

texts: I transferred some bitcoins from one of my online wallet to my Trezor. When the transaction is in unconfirmed mode I unplugged my Trezor. Then after I plugin my Trezor that transaction somehow did not show up on my Trezor. Now what should I do?


texts: What is the downside of not using Proof of Work for validator selection?

texts:
Bitcoin uses Proof of Work for two things: one is to secure the blockchain with strong cryptographic signatures like a Merkle tree, and the other is to crown the validator which "mines" a solution as THE validator (dictator) who determines which transactions to broadcast in that block. If they blacklist your address (or charge large fees) and don't want to accept your transaction then maybe another validator will eventually accept it.

But why do we need Proof of Work for the second thing? What's wrong with Proof of Correctness as Ripple uses, or Delegated Proof of Stake as LISK uses, for example? Why are they considered "not decentralized" while Bitcoin is said to be "decentralized" despite the arms race that has caused a few mining pools in China to control more than 51% of the mining power in practice?

What is wrong with a community electing 101 random validators like with LISK for example? How can this be gamed to reduce people's freedom to transact or have their transactions confirmed? The worst thing is some address may be blacklisted by a few validators (eg under pressure from a government law) but the same can happen with bitcoin miners, since we know who they are. So what's the disadvantage of Delegated Proof of Stake?

Here are the advantages: less waste of electricity, faster consensus, and possibly more decentralization in practice.

If I am right and this doesn't have any serious disadvantages, it should be rather trivial to make a cryptocurrency with delegated proof-of-stake electing N (odd number) validators.


texts: Wallet is encrypted and currently locked, How can get unencrypted (unlocked) it?

texts:
Wallet is encrypted and currently locked, How can I unencrypted the wallet to unlock?
Because of my Bitcoin wallet not getting synchronising currently, so I could not get bitcoin balance on one of my address in wallet.


texts: Is it possible to mine altcoin with antminer?

texts:
Uh..I'm not sure if it's allowed to ask this kind of question here but anyway...

I saw some comments at other forum said that theoretically it's possible to use like antminer s9 from bitmain to mine other SHA-256 based altcoin, and I'm wondering how to do it practically.

There is a place for SD card on S9 so I was thinking will it be just like what we do to GPU miners. We download mining software from mining pool, save it to the SSD, and run it.

So I checked those S9 set-up tutorial but it seems like I was wrong, there wasn't any step including download anything from mining pool.

Did anyone here try similar things before?

And I know that this kind of ASIC miners are optimized for certain kind of coins. But for example, is S9 optimized for bitcoin or for SHA-256 algorithm?

Thanks a lot.


texts:
In my Electrum wallet I can open the Network Window and view Nodes I'm connected to. Here's an example: electrum4101870.fullhealth.net. I can also find public nodes at https://bitnodes.earn.com/nodes/leaderboard.

Is my wallet streaming data from these peers? If so, how?

My understanding is that in order to stay connected to a node you need to exchange messages about the chain...

Or, is there a way I can connect to a node and just read outgoing information, such as new blocks + transactions.

Thanks


texts: In compressed public keys, is the 2 or 3 the parity or the sign?

texts:
In different places I've read that the 2 or 3 is the sign or is the parity of the elided Y coordinate?
Which of these is it, or are the sign and parity equivalent in some way?


texts: Why was/is Bitcoin written in C++ instead of C?

texts:
Why C++ and not C? Are there some features of C++ not present in C required for Bitcoin to function as it does?

I can see that a similar question has been asked before but I am more curious as to the specific features of C++ meaning that it was chosen for for Bitcoin's codebase instead of C (under the very large assumption it wasn't written in C++ purely as Satoshi's favourite language).


texts: How do I retrieve my backed up wallet to Bitcoin Core?

texts: I backed up my Bitcoin wallet on a drive for safety. Luck has it that my computer crashed. So now I downloaded Bitcoin Core, but do not how to retrieve my backup. Please help. thanks


texts: What would be a rational subkey depth to use so that my address is infeasible to locate via a systematic search?

texts:
Using pycoin.

ku <ext_pri_key> -s 1/4/6/2/8/4/2/5.......

How many levels deep into the tree would I need to go (using only single digits) before it would be infeasible for an attacker to find it using a systematic search.

Twenty levels deep I thought would be adequate:

10**20 = 100000000000000000000

I know there are more effictive ways to obscure your address but I'm interested in this particular use case.

Thanks.


texts: Basic questions about lightning network HTLC

texts:
I'm reading about lightning and I have a few questions:

The HTLC contract seems to be different at each new path payment channel is opened (due to a different Hash value that needs to be provided), but from my understatement, the channel opens in an independent and in advance to the payments in that channels, between two parties.
How is it possible? Does the HTLC is not written on the blockchain?
This part confuses me.
Are there are known ways to extend the time of a channel before the predefined period time is over? (without closing and opening a new channel)?

Thanks.


texts: Is there a service that shows up used addresses containing a substring?

texts: Is there a service that searches the blockchain with a string or possibly a regex to find out a set of possible addresses, say if I only know a half of a public address?


texts: Why not hardened keys in addresses BIP44?

texts:
Being aware of the one weakness of BIP32:

  One weakness that may not be immediately obvious, is that knowledge of a parent extended public key plus any non-hardened private key descending from it is equivalent to knowing the parent extended private key (and thus every private and public key descending from it). This means that extended public keys must be treated more carefully than regular public keys. It is also the reason for the existence of hardened keys, and why they are used for the account level in the tree. This way, a leak of account-specific (or below) private key never risks compromising the master or other accounts.

Why does BIP44 use non-hardened keys in the last 2 levels if it is still risky for the change/internal account? Wouldn't it be better to use always hardened keys?

m / purpose' / coin_type' / account' / change / address_index


texts: What precautions should i do to avoid being scammed for Bitcoins?

texts: I am a modest follower of Bitcoins and other Altcoins though recently i was scammed by few fake and fraudulent online buyers in a few days time when trading for Bitcoins.I never been scammed for any other currency ever so far over the internet and i am a very active online user but didn't have good experience with Bitcoins.All suggestions will be highly appreciated about how to escape from BTC scams Online as BTC is the X-Generation currency and i love it too.


texts: I accidentally deleted all the files that the standard bitcoin client stores to disk, except blk*.dat files. When I run bitcoind, he write that he doing sync. This sync is very very slow. What does bitcoind doing with this blk*.dat files while sync? And why there is need to connect to the internet during sync (it did not work without internet)?


texts: How many hash calculation is needed to reach one BTC?

texts:
What I am asking for is a formula and it's source of numbers to put in there and calculate how many hashes must be calculated to get 1 bitcoin today(or every other day in future)?

For example, if I put 1,000,000(1TH/S) in hash rate field of the table of the this site http://www.alcula.com/calculators/finance/bitcoin-mining/ , it gives me

  "Average time to find one block: 1386.91 years"

, but I am not sure if it's calculation is true? I also like to know the formula that website uses?


texts: bitcoin-cli getbalance does not match balance with bitcoin-cli listtransactions

texts:
version of bitcoin-cli 0.17.1

when I try

  bitcoin-cli getbalance

I get balance 0.00010471 BTC

when I try

  bitcoin-cli listtransactions "*" 1000000 >aaa.txt

and then calculate

  SUM(receive) - SUM(send) - SUM(fee)

I get 1.18202354 BTC

WHY???


texts: Why does bitcoinj need block headers and how it gets transactions

texts:
From log files and database it's obvious, that bitcoinj downloads block headers for whole blockchain history. If I'm not mistaken, it's only 80bytes hash. Why do we need to do this.

I understand that we need to build list of UTXO for every address used by bitcoinj wallet, but how do we get them from headers ?

How are transactions found ? Most efficient would be to query indexed blockchain by address, but full node bitcoind does not support this. I expect it's related to block headers but cannot figure out how.


texts: A bitcoin trader opened a blockchain wallet for me and then sent me my profit but it is non-spendable. I know they can no longer get into my account because I changed the password and I have two-step verification. I don't have the private key. How can I get the private key?


texts: Can I use Multibit private key for paper wallet?

texts:
I plan to export the private keys from Multibit, keep those and delete everything else.

Now I read about Multibit having some kind of hidden mechanism for spare adresses within a wallet. Would my approach still work or do I risk losing the BTC in the wallet?


texts: If I lose a Trezor then how does the replacement get access to the same wallet?

texts:
I am pretty confused.  What I understand is that when I buy a Trezor then it gives me some words that I need to copy down.  When the Trezor starts up does it then automatically create some Bitcoin addresses and keys?

If I lose my Trezor, then how does a replacement know about my previously created Bitcoin addresses and keys?


texts: I have a Bitcoin Core wallet. 4 days ago my password worked. Now I can't send bitcoins from my wallet: the password is wrong.  What happened?  Please help, all my money is there.  I did not change the password phrase and I am sure I remember my password.  How can I resolve my problem?


texts: Bitcoin transaction stuck for more than a week

texts:
This transaction is stuck for more than a week, it keep saying in electrum that it is unconfirmed:

https://blockchain.info/tx/622caee53701359b90df448163fcf36f36a5354ada7c01b5f7c1b8f7851080ee

It disappeared from blockchain and other block explorer and it came back with a new date yesterday and today.

I am patient, but seeing that the dates were refreshed is kind of weird.

RBF was not enabled when I sent, and I've put max fees available in my wallet, which is 1 mBTC/KB and it is not enough.

Any idea what I can do?

I tried everything listed here:

Why is my transaction not getting confirmed and what can I do about it?

And nothing can work in my situation.


texts: How long does it take to Sync my Litecoin Core Wallet?

texts:
I transferred litecoin from Coinbase to my LTC Wallet. I downloaded the wallet from Litecoin.org and it says it has to sync first before it can accept the transfer. Currently, it says that it is about 2 days to Sync. Is this the standard tome for the first time I install the Wallet or will this be every time?

As always thanks to the group.


texts: Does rpcpassword need to be non-obvious in bitcoind?

texts:
I'm syncing a full BTC node onto an external hard drive, which I'm connecting to by USB. I've created a bitcoin.conf file which sets a very insecure rpcpassword. This is literally the only field I put in the bitcoin.conf file. In what way does this matter?

(I've just changed the password. Should I restart the sync, given that it's 49% through?)


texts: I'm developing on regtest mode and it seems that the fees I specify in every transaction are not included on every new mined block (generate). I only view (listunspent) a new 50 btc coinbase utxo at the miner node. So how can I catch the fees on regtest mode?


texts: What is the Ripple equivalent of the "51% attack?"

texts:
In Bitcoin, if a participant gains control of more than 50% of the hash power, they can execute a double-spending attack. The "attack" could come from within, say if the existing powerful miners decide to change the rules.

Does Ripple have a similar problem, where a few people can effectively take control of the system? If yes, how does it work?


texts:
I don't know if this is the best place to ask this, but I've been reading about an interesting cryptocurrency called IOTA which doesn't use a blockchain exactly but instead uses a directed acyclic graph.
https://www.iotatoken.com/IOTA_Whitepaper.pdf

There also are no dedicated miners, but instead you have to validate other transactions in order to make transactions.  My question is the following:

If there are no dedicated miners, couldn't you get 51% of the computing power simply by making 51% of the transactions? And if so, isn't this a really big problem for the security of it?


texts: How can you tell if you're at the end of an incomplete blk*.dat file?

texts:
I've been parsing the blk*.dat files using fread().

Let's say this is the basic structure of a blk.dat file:

[magicbyte] [blockheader] [transactions]
[magicbyte] [blockheader] [transactions]
...
[magicbyte] [blockheader] [transactions]

When parsing, I start by reading the first 4 bytes.

If it's equal to D9B4BEF9 (magicbyte), I gather the [blockheader] and [transactions] data.
If I get NULL, I assume that I've reached the end of the blk.dat file and move on to the next one (if there is one).
If I get 00000000, I assume that the blk.dat file is incomplete, and I keep re-reading it.

Is this a reliable way to parse the blk.dat files? The 00000000 check is what I'm most unsure of.


texts: Bitcoin Wallet for Android - permission denied decrypting the wallet backup file using OpenSSL

texts:
I've followed the advice found on the https://github.com/bitcoin-wallet/bitcoin-wallet/blob/master/wallet/README.recover.md, but I'm having issues decrypted a wallet backup file

When I run below line

openssl enc -d -aes-256-cbc -md md5 -a -in bitcoin-wallet-backup-2017-12-25 > bitcoin-wallet-decrypted-backup

I got below error message

$ openssl enc -d -aes-256-cbc -md md5 -a -in bitcoin-wallet-backup-2017-12-25 > bitcoin-wallet-decrypted-backup
bitcoin-wallet-backup-2017-12-25: Permission denied
140623991867032:error:0200100D:system library:fopen:Permission denied:bss_file.c:398:fopen('bitcoin-wallet-backup-2017-12-25','r')
140623991867032:error:20074002:BIO routines:FILE_CTRL:system lib:bss_file.c:400:

Is there something wrong?


texts: On multibit how do I update my sending address?

texts:
I have bitcoin in my transactions but it does not appear in my wallet.
It says updates stopped