Blockchain.info AND Blockexplorer.com down?

[lpn209]

Do you need to need to back up your wallet each time your balance increases?

Yes I think so but you can set it so it automatically sends you one each time it happens.

NO!
A backup is sent by email each time you add a wallet in your account, not each time some uBTC are sent to you.

You just need the private key of your wallet to back it up: for blockchain, just use the "paper" button and print the paper wallet(s) generated, with the qr codes. And you're ok, you could even import this key in any other wallet program to spend your BTC as you like.

The private key(s) is the one and only necessary thing to backup in a safe place. Even the public key is generated from it.

Thanks, so doing one backup is fine, even if your balance increases or decreases, only needed if you add new addresses to the wallet? The private key, is this the "identifier" that is requested when logging onto blockchain.info?  

No, you need your private key to sign a transaction, the identifier requested is a login identifier.

Sorry if this sounds stupid, but is that the password used to login into the account? the private key? If not, could you point me in the direction where I may be able to to get this from my online wallet , thanks

[kik1977]

A private key  is random 256 bit number stored in the wallet (not the key to access it) and are used by it to sign transactions. The private key is part of a key pair, the other part being a public key, a number calculated from the private key using elliptic curve algorithm.
The bitcoin address is a base58check encoded RIPEMD-160 hash of a SHA-256 hash of the public key.  If you don't know what a hash is, it's a mathematical function.

Private key > Public Key > address

Those functions are not reversible (or at least it is not computationally feasible to calculate the private key when you have only the public key and the public key when you have the address), so you can disclose the address without fear of your public key being calculated. But if you have a private key, you can calculate all the rest and therefore spend every bitcoin associated with that address.

The identifier requested by blockchain, it's simply a login identifier for blockchain, like your login account for any other service. It's not connected in any way with your private key.

[lpn209]

A private key  is random 256 bit number stored in the wallet (not the key to access it) and are used by it to sign transactions. The private key is part of a key pair, the other part being a public key, a number calculated from the private key using elliptic curve algorithm.
The bitcoin address is a base58check encoded RIPEMD-160 hash of a SHA-256 hash of the public key.  If you don't know what a hash is, it's a mathematical function.

Private key > Public Key > address

Those functions are not reversible (or at least it is not computationally feasible to calculate the private key when you have only the public key and the public key when you have the address), so you can disclose the address without fear of your public key being calculated. But if you have a private key, you can calculate all the rest and therefore spend every bitcoin associated with that address.

The identifier requested by blockchain, it's simply a login identifier for blockchain, like your login account for any other service. It's not connected in any way with your private key.

Thanks for the detailed explanation 

If I have backed up my BTC blockchain.info wallet do I need to use this in anyway, or just make sure my back up is protected as the private key is a means to hack my account and not needed by myself for the operation of my wallet? many thanks

[turvarya]

A private key  is random 256 bit number stored in the wallet (not the key to access it) and are used by it to sign transactions. The private key is part of a key pair, the other part being a public key, a number calculated from the private key using elliptic curve algorithm.
The bitcoin address is a base58check encoded RIPEMD-160 hash of a SHA-256 hash of the public key.  If you don't know what a hash is, it's a mathematical function.

Private key > Public Key > address

Those functions are not reversible (or at least it is not computationally feasible to calculate the private key when you have only the public key and the public key when you have the address), so you can disclose the address without fear of your public key being calculated. But if you have a private key, you can calculate all the rest and therefore spend every bitcoin associated with that address.

The identifier requested by blockchain, it's simply a login identifier for blockchain, like your login account for any other service. It's not connected in any way with your private key.

Thanks for the detailed explanation 

If I have backed up my BTC blockchain.info wallet do I need to use this in anyway, or just make sure my back up is protected as the private key is a means to hack my account and not needed by myself for the operation of my wallet? many thanks

You still confuss 2 things.

Privat Key=Wallet
and
blockchain.info=Wallet Software

(that is also not 100% accurat)

If someone has your Privat Key, he doesn't need your blockchain account.
You can Import a privat key in any wallet-software(e.g. Bitcoin Core/Bitcoin QT) and just spend the Bitcoin as you like.

A privat key is the Thing you have to Keep most secure.
Your blockchain.info-credentials just gives you acces to the private key and the functionality to use your wallet.

I hope, that helped.

[kik1977]

You can also choose (like I do) to keep most of your bitcoins in a paper wallet and load it on blockchai as a "watch only" address, which means that you don't provide BC with your private key, but your address only. Even if BC is hacked or they shut down, you don't loose anything since you never gave them your private key.

If you need to actually "use" some coins, just keep that small amount "loaded" with the private key on BC and keep all the rest in cold storage.

[Krang]

You can also choose (like I do) to keep most of your bitcoins in a paper wallet and load it on blockchai as a "watch only" address, which means that you don't provide BC with your private key, but your address only. Even if BC is hacked or they shut down, you don't loose anything since you never gave them your private key.

Can you do this with the app and does it still notify you when you spend or recieve coins?

[lpn209]

A private key  is random 256 bit number stored in the wallet (not the key to access it) and are used by it to sign transactions. The private key is part of a key pair, the other part being a public key, a number calculated from the private key using elliptic curve algorithm.
The bitcoin address is a base58check encoded RIPEMD-160 hash of a SHA-256 hash of the public key.  If you don't know what a hash is, it's a mathematical function.

Private key > Public Key > address

Those functions are not reversible (or at least it is not computationally feasible to calculate the private key when you have only the public key and the public key when you have the address), so you can disclose the address without fear of your public key being calculated. But if you have a private key, you can calculate all the rest and therefore spend every bitcoin associated with that address.

The identifier requested by blockchain, it's simply a login identifier for blockchain, like your login account for any other service. It's not connected in any way with your private key.

Thanks for the detailed explanation 

If I have backed up my BTC blockchain.info wallet do I need to use this in anyway, or just make sure my back up is protected as the private key is a means to hack my account and not needed by myself for the operation of my wallet? many thanks

You still confuss 2 things.

Privat Key=Wallet
and
blockchain.info=Wallet Software

(that is also not 100% accurat)

If someone has your Privat Key, he doesn't need your blockchain account.
You can Import a privat key in any wallet-software(e.g. Bitcoin Core/Bitcoin QT) and just spend the Bitcoin as you like.

A privat key is the Thing you have to Keep most secure.
Your blockchain.info-credentials just gives you acces to the private key and the functionality to use your wallet.

I hope, that helped.

Thanks, yes I was slightly confused as to whether they would need access to my blockchain.info account if they were able to get my private key from my wallet. I have backed up my wallet on a couple of usb sticks but will look into cold storage once I have done alot more research.

You can also choose (like I do) to keep most of your bitcoins in a paper wallet and load it on blockchai as a "watch only" address, which means that you don't provide BC with your private key, but your address only. Even if BC is hacked or they shut down, you don't loose anything since you never gave them your private key.

If you need to actually "use" some coins, just keep that small amount "loaded" with the private key on BC and keep all the rest in cold storage.

I chose the email wallet option, I know its not as secure, but I have deleted the backup attachment email from blockchain.info and will go ahead and download a paper back up now for added security. Thanks for the advice

[kik1977]

You can also choose (like I do) to keep most of your bitcoins in a paper wallet and load it on blockchai as a "watch only" address, which means that you don't provide BC with your private key, but your address only. Even if BC is hacked or they shut down, you don't loose anything since you never gave them your private key.

Can you do this with the app and does it still notify you when you spend or recieve coins?

Not sure if the newer version on android can, I have the old version and it doesn't notify, but you can watch the address anytime you want. If you don't need to spend or move big amounts of coins suddenly and quickly, stay safe and keep the greatest amount of your bitcoins in a safe cold wallet!

[311]

Is blockexplorer tied to blockchain.info in any way? Weird they would go down at the same time.