Backup your wallet.dat file
No there's some useful new information.
The wallet.dat file is what you should backup.
Back up the wallet.dat . . .
Backup wallet.dat . . .
Encrypt your wallet using the bitcoin client, and back up the wallet.dat . . .
Topic: How to protect send addresses? (Read 579 times)
No there's some useful new information.
Encrypt your wallet using the bitcoin client, and back up the wallet.dat EVERY time you create a new receive address.
Assuming you are talking about the Bitcoin-Qt wallet, this is a bit excessive if you generate receive addresses regularly, and isn't good enough if you send a lot of transactions and don't generate many new receive addresses. Note that every time you send a transaction the Bitcoin-Qt client uses a new address.
Don't forget that if you ever backed up your wallet before and it wasn't encrypted, you should probably send all the coins to a new wallet and encrypt/back it up. This way a copy laying around unencrypted can't ever be found and 'picked up' by a malicious program.
This isn't generally necessary as long as you don't re-use any of the receive addresses you generated prior to encrypting. It wouldn't be a bad idea to generate a new receive address after encrypting and send your entire balance to the new receive address though.
Backup your wallet.dat file
Encrypt your wallet using the bitcoin client, and back up the wallet.dat EVERY time you create a new receive address.
Don't forget that if you ever backed up your wallet before and it wasn't encrypted, you should probably send all the coins to a new wallet and encrypt/back it up. This way a copy laying around unencrypted can't ever be found and 'picked up' by a malicious program.
Don't forget that if you ever backed up your wallet before and it wasn't encrypted, you should probably send all the coins to a new wallet and encrypt/back it up. This way a copy laying around unencrypted can't ever be found and 'picked up' by a malicious program.
Backup wallet.dat every 100 transactions 
That's not often enough.
Each new receive addresses that you generate reduces the number of transactions that are protected by the backup.
In addition it wouldn't be a bad idea to keep a few recent backups in case the most recent one is damaged or unusable.
I'd suggest backing up when the sum of receive addresses generated and transactions sent since the last backup is around 25. Then keep the 3 most recent backups.
Backup wallet.dat every 100 transactions
If you just hide it from the world, no one would ever know..
Back up the wallet.dat and you only need to do it once (unless you create more than 100 receiving addresses).
This is not true. You need to back up regularly. Bitcoin-Qt uses a new address (that it keeps hidden from you in the wallet.dat file) every time you SEND a transaction. It also uses a new address every time you click the "New Address" button. When you've use up 100 address (including the hidden ones from transactions you create to send bitcoins), your backup will no longer be any good.
If the old wallet is old enough? Yes. And coins are sent to a new address every time you create a transaction.
Back up the wallet.dat and you only need to do it once (unless you create more than 100 receiving addresses).
This is not true. You need to back up regularly. Bitcoin-Qt uses a new address (that it keeps hidden from you in the wallet.dat file) every time you SEND a transaction. It also uses a new address every time you click the "New Address" button. When you've use up 100 address (including the hidden ones from transactions you create to send bitcoins), your backup will no longer be any good.
so is it to say : coins send to the new addr. will lost when you use an old wallet?
Back up the wallet.dat and you only need to do it once (unless you create more than 100 receiving addresses).
This is not true. You need to back up regularly. Bitcoin-Qt uses a new address (that it keeps hidden from you in the wallet.dat file) every time you SEND a transaction. It also uses a new address every time you click the "New Address" button. When you've use up 100 address (including the hidden ones from transactions you create to send bitcoins), your backup will no longer be any good.
The wallet.dat file is what you should backup.
How do you protect and retain your send addresses with bitcoin-qt, without backing up the entire folder and restoring it? Is there a particular file that must be saved in order to protect this information?
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