Hello community! I just wanted to know what happens, technically, when someone sends Netcoins to my wallet-address and I'm not on my computer and so my wallet isn't online/active (not opened as a program)?
Also I see that my wallet syncs itself after every start, what happens there? Could I get Netcoins although my wallet wasn't synced for weeks (that brings us back to question #1)?
You don't own coins, you own the keys to them. It don't matter if your wallet is on or not. When your wallet syncs up to the point the coins were credited, that's when they come through. The syncing is downloading the transactions of all coins, yours, mine, his, hers.
All crypto coins, like bitcoin and work using a blockchain. This is a publically shared and searchable list of all the transactions that were ever conducted on that coin since it launched. It is kind of like the pages in an accounts ledger, except it is public information the whole world can see. The blockchain is duplicated around the network and each 'page' or 'block' of transactions in the ledger is signed by a 'miner' program. This program computes a complex function based on the actual transactions in the block to 'verify and seal' each block of transactions in the ledger. This process takes a lot of computational effort to achieve. If anybody tries to tamper with the historic transactions, it will break the signature for that block, and every subsequent block because the previous block signature is included as part of the next block, and so all the transactions are linked in a signed and verified 'block chain'.
Block Difficulty and Transaction Confirmations
The fact that it is time-consuming to sign a block is what protects the ledger against people tampering with past transactions (like if somebody attempted to delete a payment they sent to you). The network constantly adjusts the difficulty of signing a block (the Block Difficulty) so that it takes an average of 1 minute for 1 computer out of all the miner programs currently running in the world to sign a block of transactions.
If a rogue miner program tries to change the transactions in a previously signed block, it will need to re-do the work to sign that block, and all subsequent blocks up to the current time.
When you see transactions appear in your wallet, it also shows a number of 'confirmations'. This is the number of new blocks that have been added to the end of the block chain and signed since the block containing that transaction. The more 'confirmations' there are, the more blocks would have to be 're-signed' by a rogue program in order to reverse that transaction. So more confirmations means more certainty that the funds are indeed yours and will not get reversed by a rogue program.
When the wallet syncs, it is reading through each and every one of the latest pages in the block chain since the last time it connected. As it does this, it looks to see if any of the transactions sent money to addresses where your wallet contains the private version of that address. If you don't sync for 24 hours, your wallet will download about 1440 blocks and check them for payments to you the next time you start it up. As it downloads the latest blocks, you might see your wallet balance increasing as it finds recent transactions for coins sent to addresses in your wallet.
So the short answer is, money people send to you gets registered as transactions in the blockchain whether your wallet is connected or not. Your wallet 'catches up' with any blocks it missed while it was away the next time you start it up, and eventually retrieves your total available balance.
Your Private Keys
The most important part of your wallet is the private key store. These private keys are how the wallet knows it has the authority to spend money sent to some of the addresses in the block chain. These keys are required in order to re-spend any coins you have received. YOU MUST BACK UP YOUR WALLETS PRIVATE KEYS to another device - like a USB stick. You can do this on the file menu in the wallet program. DO IT NOW. If you don't do this, and your computer fails, your coins are lost FOREVER. Really, completely, totally, unspendable, forevermore. Nobody in the world will be able to help you. At all. So back up your wallet keys to another device.
Your private keys are held in a single file called wallet.dat. As long as you have this wallet.dat file, you could install the wallet program on a fresh computer, substitute your backed up wallet.dat, then download the entire blockchain all over again from scratch and obtain your full coin balance.
The second thing about your private keys is that you can lock (encrypt) the wallet.dat file with a password so it is useless to anybody who tries to steal it if they don't know the password. You can encrypt your wallet on the settings menu in the program. A locked (encrypted) wallet can still receive funds, but can't spend any until you enter the pass phrase again.
Again, the same rules apply, if you forget the passphrase, or mistype something when you set it, your coins are unspendable forever!
If 5 years from now, you have a life-changing amount of netcoins in your wallet, your spouse/kids need to know how to unlock the wallet if you go under a bus or a thief walks off with your pc. If they don't a) have a copy of wallet.dat, and b) know the passphrase if you locked it, the coins are lost forever.
-QT, Paper wallets and others
The -QT wallet is a way of managing coins and the signatures required to spend them on a live computer. As such it is known as a 'hot' wallet. There are other 'cold storage' solutions like paper wallets that can provide an extra layer of security (an air-gap) between the internet world and the private signatures required to spend your netcoins.
Remember to receive funds you just need a public address, and the private key associated with that address so you can subsequently spend them. A paper wallet is simply a piece of paper showing a public address and its associated private key. You send funds to the public address on the paper. Then store the paper away safely. When you want to spend the funds, you simply type the private key written on the paper into a hot-wallet like -qt to subsequently obtain the funds locked up in that piece of paper from block chain and send them elsewhere.
I have sent some netcoins to paper wallet addresses and given them to my kids. Hopefully one day those pieces of paper will pay their college fees. Or maybe buy them a house. Or a Pacific island. Or a pencil case. Who knows? Exciting, isn't it!
BigJ: is on the list to be added to the gaming platform vote.jalapen.io/coin/vote but WE NEED YOUR VOTE! Please take a minute and vote and don't forget to confirm the email so your vote counts and doesn't get removed. Go NET!!
Mar 31, 2018 6:33:51 GMT