I could tell you what a reasonable high fee is for today, but it might be wrong tomorrow. How a high a good fee is greatly depends on the number of transactions that try to get a confirmation as well as the fee they pay.

As someone accepting bitcoin as payment you have essentially 3 options.

#1 you learn the details
#2 you use a service like bitpay as they know the details. They have the scrips ready and AFAIK they also have contracts with mining pools that ensure confirmations.
#3 you accept that a small number of payments might fail.
#4 well, you can wait for a confirmation, but that usually is not acceptable for stores.



This sounds like 1 satoshi is enough of a fee to get a confirmation.


This would require the person accepting the payments to look up the transaction and be able to judge the fee based on the current state of the network. Not typicall what you expect from someone handling the register.


The fee can not be increases once the transaction is broadcasted.

Well that was quick. ShortHonesty can you confirm?

Not if the transaction is valid (signed) and the receiver has already seen it. Lets assume Im Joe Dip here and you send me 1.1 BTC without a fee. Currently thats a bad idea, but you say you are sorry and I believe you.

Now it would take a long time for the transaction to get a confirmation. I could also happen, that the entire network forgets about the transaction and it essentially never happened. I can however - and would in this case - remind the network about your transaction. For 1.1 BTC worth I would probably write a small script that does this every 30-60 minutes. You can now remove the transaction from your own wallet, but I will keep reminding the rest of the network until its confirmed. This will make it almost impossible for you to issue a different transaction that sends the coins elsewhere.

If we both agree that the TX should be removed and redone. I would not write nor start the script. You remove the TX from your wallet and we both wait a few days until the network forgot about it. This essentially "stops" the transaction, unless someone else rebroadcasts it for some reason (or none at all).

If the transaction pays a reasonable high fee, you can remove it from your wallet all you want. Chances are it gets confirmed anyway.

Well the server crashed, yes. Usually a file gets corrupted if data is accessed during the crash. I would not expect that happening with your live wallet.dat as well as your backup even if they are both on the same system. Unless you run automated backups and it crashed at the exact time the wallet.dat was due. It might help if you replace the whole dir, not sure. Maybe its not actually the wallet.dat files but something else. Replacing the entire dir might give some clues.

Do you have any other backups or any idea why the backup could be corrupted as well as the normal wallet.dat?

Is this the original wallet file or the backup? It looks like the wallet.dat was corrupted and the private keys are damaged. Odd that it would happen with your live wallet.dat as well as with your backup.

There are no IP address on the blockchain. What migh refer to are the IPs shown by blockchain.info a service. Its the IP of the full node that told them about the TX and most likely has nothing to do with the person the issued the TX.

To hide your IP from a service you can use a VPN, yes.

If you keep your system updated and dont directly download malware it is very difficult or expensive to break into it. It would require the use of what is called 0-day. An exploit that is not fixed and was sold in secret. This is not something your average attack has available.


There is no easy answer to this, because it depends. Multisig can be more secure depending on the circumstances. Who can sign along with you? If its you on a different computer, how secure is that computer in comparison to one that is never online?


It can, but its even more difficult than attacking a well updated and clean computer.

Whats cold storrage? You have an online computer that shows you your balance, but has no private keys. You use this computer to create an unsigned transaction. You transfer this unsigned transaction to the offline computer. This is where it could break apart. E.g. if your online computer has malware that spreads via USB sticks and you use an USB-stick to get the TX from the online to the offline machine, chances are its compromised. The malware will have problems getting any data out though. You could also just transfer the data by hand, e.g. type on your offline system what you see on your online system. Once the TX is on the offline system you load it into the wallet software, check if its what you want, sign it and transfer it back to the online system. The online system is used to broadcast the signed TX to the network.

Spam is against the rule in all languages. Just because its in chinese and in the chinese section does not make it ok to spam. Not sure what your logic behind that is.

Its pretty obvious spam as its unrelated to crypto currencies, at least according to the translation and the translation of the site.

There are a few common topics for what is spammed here:

#1 nonsense
#2 educational related like the one in the OP
#3 grow your penis/muscle/etc. spam
#4 some other health nonsense

No. Keep in mind this is all "default settings" and any miner can change them around however they want.

There are 50KByte per Block that are reserved for free transactions (no fee). They are put in sorted by priority, highest first. Once the 50KByte are filled up the remaining TX are sorted by fee per byte until the block is full or no more transactions are left. The transactions with fees are competing against eachother and those without fees. There is however more space for those that pay a fee. If there are not enough transactions to fill a block, all get confirmed. This would include TX without fee and a low priority as they are at the bottom of the queue.

Since there are always transaction that await a confirmations fees needed to get a quick confirmation are on the rise.

Kinda. Priority comes from inputs. Inputs are the coins you have received and now want to spend (create an output). The older (in number of confirmations) and larger (in bitcoin) an input is the higher is its priority. If the whole transaction (can have several inputs and outputs) has not a high enough priority to be confirmed without fee, the fee is a supplement for the missing priority.

High enough is usually 1 bitcoin day. That is 1 input worth 1 btc with 1 days worth of confirmations (144) used to create two outputs. If the input is only 0.1 BTC it would require 1440 (10 days) confirmations, etc.

Thats not how bitcoin core works. It rebroadcasts the TX so the network does not forget about it. OP would have to remove the TX for that to stop.

Fair enough, here is my prediction of your success: 0%

At least offer escrow, otherwise you sound like those bad phishing mails that go around.

So a "real" currency can only reduce in value? Im convinced where do I sign up?

Tools -> Reset Blockchain and Transactions should do it.

This smells so bad...

anyway: how?

The backup might fix it or it might have the same issue.

Instead of -rescan try -zapwallettxes if the backup does not work.

If that does not work either, try -zapwallettxes=2 this will drop all meta data about transactions (labels, etc.) though.

No.

Because a transaction has no IP address attached to it.
Because if you broadcast a transaction that is spending coins "from"[1] an address you do so to several peers and the TX is no different from those that you relay.
Because your client connects to servers that are under control by a single entity, but the requests are such that they can not link the IP to an address.

Yes.

Because you use a service (e.g. blockchain.info) to handle your coins and dont mask your IP, e.g. via Tor.
Because all the node you are connected to are under control by the same entity. Known as sybil attack.
Because your client connects to servers that are under control by a single entity.


[1] there is no such thing as a from address, its just easier to use the word here. Technically its just another transaction that is referenced.

This is 400% zoom on chrome.



It works for some slides, but its mostly annoying at a level that I wont bother reading 75 slides. Tried FF and Tor Browser as well.

Is there a bigger version?