After you have generated all the addresses which have a balance,
you can use this (slightly more elegant) command to dump all the private keys which contain some coins:

Its 3 out of 24.




3 words (with a character set of 2048) conforms 8.589.934.592 possibilities.
Where 3 missing characters of a private key (with a char set of 16, assuming hex represantation) conforms to 4.096 possibilities.

So, no it would NOT be easier to crack a few words in a seed than a few chars in a priv key.

In 2010 you most probably have used bitcoin core (QT).

Do you still have a wallet file and are trying to see whether coins are stored?
If your file ends with .dat its a file from core.

Before trying to open your wallet, make sure to do several copys and back them up safely.
Also, if you think there might be 'bigger' amounts, don't simply put the wallet file onto an eventually infected PC.

The most secure way to check whether you have coins in your wallet would be to open it with the core wallet on an offline PC and check the balance of your addresses
on an online pc via a block explorer.

I'll give it a try:

You can think of hashing as a 'mathematical equation' where you produce a (random) output depending on the input.
Now, when you mine, you are basically calculating hashes (with the TX's as input) until you have found a hash with X leading 0's.
How much 0's are needed is defined by the difficulty of the network. This difficulty adjusts every 2 weeks to get a 6 blocks per hour 'speed'.
Each time you mine a block the first transaction in this block is the coinbase transaction (has nothing to do with coinbase.com).
This coinbase transaction contains the freshly mined BTC's to the miners address.

Basically its a probability game. The miner with the highest hashrate (most calculations per second) has the highest chance of mining a block (calculating a valid hash) proportionally.


Thats just a very basic description of the mining process. Feel free to ask more detailed questions.

I wouldn't say 99%.. but it definetely can be somehow safe.
But there are still exploits which simply arent fixed yet and are a perfect entry point for malware targeting crypto user.
There are things which you can't protect yourself from with a desktop wallet.

Additionally the 'basic security precautions' are probably not achievable/doable for 90%+ of the daily windows user.




You can enjoy the electrum GUI and still have the security of a hardware wallet.
When creating a wallet in electrum you have the choice to add a HW wallet (which will hold the private keys / do the TX signing).

Blocks don't get 'chosen'.
Blocks get mined. With an average of 6 blocks per hour.

Fees are dependend on how many transactions are waiting to get confirmed and how much user are willing to pay for a faster transaction.




The minimum fee to get a transaction confirmed within a reasonable timeframe was way above 1$ in december.
This depends 1) on the amount of transactions and 2) on the $-value of BTC.

If you really had 2FA 'activated' the most likely 2 things which happened (in my opinion) are those:
1) You have downloaded a malicious version of electrum and therefore didn't have any real 2FA activated.
2) You are completely compromised. Someone has access to a) your PC and b) has either cloned your mobile or cloned your GA code(s).

You should definetely scan your system for any malware. And to be on the safe side you should setup a fresh OS install.

Additionally, the next time you are going to store BTC: Make sure to store relatively high amounts (like 1 BTC is currently) safe offline (hardware or paper wallet).

Thats what i assumed. But, without offending you, i don't think your fork will be somehow innovative/valuable.
There is a lot of expertise necessary to improve the bitcoin protocol with a hard fork.

Im not quite sure how you can bring that much improvements into it without googling the .icns extension first 

It might be better for you to create an ERC20 token on ethereum. There are lots of tutorials available on the internet.

What are you trying to accomplish? Whats the reason?




You can't 'break down SHA-Hash into 2mb blocks'.
SHA is a hash function. Depending on which you choose it will create an output with the length X (e.g. 256 bit for SHA-256).
SHA is not used for encryption. Its a one-way function. Easy to calculate forwards but almost impossible backwards





An email?




The file should be encrypted/decrypted once. If every node would be able to decrypt a file.. what sense would the encryption then have?




For me this seems like merging a few altcoin projects to create one inconsistent theoretical project.   

Could you clarify that statement?

Are you trying to connect your node (at your physical location) with the 'bitcoin network' via VPN? [1]
Or are you trying to make that node only 'accessable' within a VPN? [2]

[1] VPN as a 'tool' to hide your IP, etc..
[2] VPN as a private network with multiple participants


It would be easier to help if you could explain what exactly you are trying to acheive?

It is going to be a light weight wallet. So most probably this is going to be a 'centralised' solution.
Every light weight client relys on an infrastructure to retreive information about the status of transactions, etc.. If thats what you understand with 'centralised'.
Core is the only (independent) full node client. Any other desktop/mobile/HW wallet is a lightweight client.

For a completely independent setup you need to have full nodes (with whole blockchain) running. For each coin you hold.

Depends on 1) where your node is located (network-wise) and 2) how the OS core runs on is configured.

Regarding 1):
Is your node inside your private network? If so, your node directly connects to your router (what else).
If your router is configured to use a VPN, the traffic from core will also be routed through VPN.

Regarding 2):
If you have a node outside of your private network and want to route everything through a VPN you have to use the VPN option of the OS.
This will lead to your node communicating via VPN.


If you clarify the topology of your network (and your setup you want to achieve) , we will be able to give you a more detailed answer.

He is talking about running -reindex command.

Either open the console of core ('Help' -> 'Debug window' -> 'Console') and type: -reindex.

Or start core via command line with -reindex as command line argument:
e.g. in linux:

OP is not trying to extract a private key out of a core wallet.
He is trying to restore a wallet (probably one private key).


@OP: It would be helpful to know how your key starts: 5.., K.. or L.. ?

BIP39 (and electrum) seeds are specified with 2048 words.




Of course, the greater your possible space of words is the harder it gets to crack/guess the seed.




A 24 word seed phrase has about the same security as the private key of bitcoins itself.
Means that with any seed longer than 24 words its 'more profitable' to 'attack' the private key instead. Please note that we are talking about more than 10⁷⁷ possibilities.
A 12 word seed gives you about 5 * 10³⁹ different seeds. Thats clearly smaller but still high enough to be considered non-crackable (currently).




Theoretically this works with every currency. It just has to be implemented.

After installing a wallet it will generate a random(!) seed. This seed will be used in 'mathematical equations' to derive your private keys.
These private keys 'allow you to spend from the corresponding address'.
There is no API necessary. Each client creates private-/public keypairs itself. There is no central authority in a decentralized system.




Depending on what language you want to use, there are quite a few libaries available which make it plain simple for you to create priv-/pub keypairs, send/receive transactions, etc...
The best way would be to google it yourself: 'bitcoin + libary + YOUR_PROG_LANGUAGE'

It does matter whether its a word or a number. This determines the searching space and therefore the amount of time you have to invest to crack that wallet.




Most modern wallets use either a 12 or 24 word seed. Thats not an information which is hidden anyway.




For huge amounts thats true. But the average joe with a few btc shouldn't care too much about such targeted attacks.
It would be way more lucrative to just steal cryptos with malware.

SegWit's purpose is not to get 'faster confirmation time'. The confirmation time (aka timeframe between 2 blocks) conforms ~10 minutes (on average).
This is hardcoded into the bitcoin protocol. Only a hardfork could change this value (which would create a new coin).




SegWit doesn't 'promise' anything. SegWit basically, among other things, reduces redundant data from transactions, making them smaller in size.

You do realize that 'finding blocks' isn't like flipping stones to find something below it?
You describe it as you were searching for those blocks in the woods and sometimes find a broken one.

If a miner publishes an invalid block, it won't get accepted. The next valid block will be added to the chain (and is going to be used for the work of the next block).

I suggest you lookup what a block [1] and a transaction [2] is. You might also read the bitcoin whitepaper [3].


[1] https://en.bitcoin.it/wiki/Block
[2] https://en.bitcoin.it/wiki/Transactions
[3] https://bitcoin.org/bitcoin.pdf

You should have read the thread. The majority of the posts here give you the answer already.
Here is a short summary of those posts:




Don't fall for scams. Noone is going to give you something for free. Neither will a "20% return investement with 100% security" really give you profits.
Use your common sense and avoid anything which "could be fishy".