<p>Nobody really knows how it's implemented, other than the developers of the site, but I doubt they keep a single wallet.dat file. They don't store the keys of each address so it could very well be that they don't even use bitcoind. </p>

<p>They could use their own implementation which would allow for better concurrency since they have lots of users accessing their wallets at once.</p>

<p>You can build a bitcoin wallet however you'd like. It doesn't have to be a <code>wallet.dat</code> file. You could even put the information of the transactions in a basic MySQL database (which is good at concurrency) and have something like PHP process and send out the transaction, and you'd have a wallet represented within a MySQL database.</p>

<p>To answer your question, I'm sure of course they do have proper backup routines of their database, just like any other website.</p>

CC BY-SA 3.0
2014-01-17T17:00:51.413Z
is there a standard wallet format ? so they can create wallet.dat upon request for each user to download, depending on there info of addresses, transactions ... etc, is this valid assumption ?
Farghaly
CC BY-SA 3.0
2014-01-17T17:07:00.337Z
They don't store your keys so I doubt they can give you a `wallet.dat` file to download. Remember that the transactions are not stored within a wallet file... they're stored in the global ledger called the blockchain. So you could simply export your keys of a wallet from blockchain.info, and import them in a client such as MultiBit, and still be able to see all your transactions.
Luca Matteis
CC BY-SA 3.0
2014-01-17T16:55:41.600Z
2014-01-17T17:01:06.323Z
2014-01-17T17:01:06.323Z
Luca Matteis
<p>As far as i know that online wallets as Blockchain.info is a Bitcoind instance that gives each user an <em>Account</em> and each account related to multiple addresses through JSON-RPC calls, how blockchain.info backup wallet of individual account ? i imagine that all accounts are stored in a single wallet.dat ! or does blockchain.info has wallet.dat for every account ?</p>

<wallet><backup>
Backup wallet of single account
Farghaly
# Backup wallet of single account

(Asked by: username_0 on 2014-01-17)

As far as i know that online wallets as Blockchain.info is a Bitcoind instance that gives each user an *Account* and each account related to multiple addresses through JSON-RPC calls, how blockchain.info backup wallet of individual account ? i imagine that all accounts are stored in a single wallet.dat ! or does blockchain.info has wallet.dat for every account ?

**Tags:** wallet, backup


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## 1 answers

### Answer by username_1 on 2014-01-17. Score: 2

Nobody really knows how it's implemented, other than the developers of the site, but I doubt they keep a single wallet.dat file. They don't store the keys of each address so it could very well be that they don't even use bitcoind.

They could use their own implementation which would allow for better concurrency since they have lots of users accessing their wallets at once.

You can build a bitcoin wallet however you'd like. It doesn't have to be a `wallet.dat` file. You could even put the information of the transactions in a basic MySQL database (which is good at concurrency) and have something like PHP process and send out the transaction, and you'd have a wallet represented within a MySQL database.

To answer your question, I'm sure of course they do have proper backup routines of their database, just like any other website.

> **Comments:**
> **username_0**: is there a standard wallet format ? so they can create wallet.dat upon request for each user to download, depending on there info of addresses, transactions ... etc, is this valid assumption ?  
> **username_1**: They don't store your keys so I doubt they can give you a `wallet.dat` file to download. Remember that the transactions are not stored within a wallet file... they're stored in the global ledger called the blockchain. So you could simply export your keys of a wallet from blockchain.info, and import them in a client such as MultiBit, and still be able to see all your transactions.  

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