Can’t spend Watch-Only coins, have I been scammed?

Inspired by Murch’s format of Why is there no such thing as a redirected, forged, or fake transaction? to create one question that is well-worded and accessible through search engines.

Recently, I’ve imported an address to my wallet that contains the bitcoins I have earned. Now I want to spend them, but my wallet shows it as “Watch only” or “Non spendable” and says “Private key for address not found”

How can I claim back my bitcoins and spend them?


Private Key has no fund

I tried to import my private key from the BTC Core Wallet into another wallet because it doesn’t work anymore, it says that there is no fund, even if it is 100%, as I can see on the Explorer.

I really need help. My Btc Core wallet is not running, but I was able to open a new wallet with my Dat.dat file and check my private key, it’s all correct.

Exchange Confirmation Requirements

What does the minimum confirmations required for a deposit mean for the security of exchanges? For example, Coinbase requires 3 confirmations for Bitcoin deposits. Suppose an adversary deposits 10 bitcoins into an exchange and has his account credited.

What stops an adversary from mining a private chain with a transaction that conflicts with his previous deposit transaction. What would this mean for the exchange? Would the user have the ability to sell the Bitcoins credited to his account and defraud the exchange?

Why is there no such thing as a redirected, forged, or fake transaction?

In the past, we had numerous questions about “fake” or “forged” transactions. Such transactions could supposedly be created even without holding any bitcoins, yet would end up in the mempool or even get accepted by the network once they are mined into a block. Other times, the recipient creates a conflicting version of the sender’s transaction, or a majority attacking miner would simply redirect all transaction outputs to themselves.

With this topic I mean to create a canonical question for a topic which is described by the following variants of a questions:

  • Why can I not just make up bitcoins?
  • Why will fraudulent transactions not get relayed on the network?
  • Why can only the owner spend their funds?
  • Why can a third party not alter the recipients of a transaction?
  • What prevents a miner from taking the funds of your transaction when creating a block?

In other words, let’s comprehensively explain:

What makes a transaction valid, how is a transaction protected against tampering, and how can nodes tell?

Here are some examples of topics that might be redirected here in the future:

Can you help me tell if my new out-of-the-box ssd for a Pi4 myNode project is DOA?

Trying to setup a node on a Pi4 with ssd and blockchain appeared to be downloading well. My router said I was gobbling data for 2hrs. Then I received the “Looking for Drive” message. I rebooted once, then shut down once, then rescan which didn’t seem to take and then reset . I don’t think reindexing is going to do anything.

Would the upgrade from 2.0 to 2.04 help?
Can I get any confirmation on here it is a DOA ssd out-of-the-box?
I watched it reboot and the SSD light flashes 3x’s and it did this 3x’s in a row, waited a few seconds did it one more time, waited a few seconds then blinked constantly for two minutes until I shut it down.

Thank you,

Do miners validate each other’s blocks?

I understand that to mine a block, miners solve a cryptographic problem and the solution can be easily verified by other nodes on the network, appending the new block to their blockchain.

But why do miners consent that some other miner managed to mine a valid block before them?
Why don’t they claim that some other miner’s block is invalid even if it actually isn’t, and buy time to mine one themselves?
Is it because all non-miners will validate anyway and miners don’t want to risk having a discarded chain?

Does secp256k1 library provide API for generating uncompressed key?

Hi I am right now want to do a make a small tool to generate some test vector for ecdsa.
Openssl is quite good, for support secp256k1 bitcoin provides an excellent library.

However, it looks what I get from secp256k1 API only the compressed key.
I find some post about how to convert the compressed key (Qx) to uncompressed key (Qx,Qy). But I just wondering if I can directly get the uncompressed key?


Port 8333 closed, fwd on Router OK, firewall port open, full-node not reachable

I have set up my bitcoin/lnd full node and found out that port 8333 is closed.

When checking using it tells me it’s down

I’ve checked the router config and port 8333 is forwarded to the IP of the node.

If I scan or use telnet to connect locally to my node, it seems to be blocked.

Also ufw has been checked and sudo ufw allow 8333/tcp has been added.

As well sudo netstat -tunlp tells me that the port is in listen state.

Now, I’m kind of stuck and looking for help.

Many thanks in advance for a reply and stay healthy.

Should I use Electrum Wallet OR Bitcoin Core as my website’s payment gateway?

I’m a developer who is building a website that need to process Bitcoin payment requests. So I need a payment gateway.

In my last project, I used Electrum wallet as payment gateway but my last project doesn’t have too much bitcoin payment requests, and electrum works fine.
But I’m afraid of electrum’s limitations and I’m not sure it’s a good idea to use electrum when processing lots of payment requests.

Bitcoin Core runs bitcoin node but it takes too much disk space (full node) or CPU usage (prune mode) and I’m afraid it’s not a good idea too.

So please tell me which one preforms better as a website’s payment gateway, and why. Thank you all for answering.