It is blockchain.info's policy to store as little information about our users as possible. Using our basic wallet service all we store is an encrypted JSON payload containing your keys which is only possible for you to decrypt. Some additional My Wallet features require information about your public keys - explained below.
My Wallet can operate in two different modes:
- Alerts Disabled If you have notifications disabled your public keys are stored encrypted inside your wallet. In this mode we are unable to view your public keys when offline and hence cannot view your balance or transactions.
- Alerts Enabled When notifications are enabled your public keys are inserted in a separate table along with your email, skype handle or google talk username. This mode does sacrifice some Anonymity as we can now see your public keys and view your wallet balance. However just because a wallet contains a public key does not necessarily mean they are the owner of said key (as you can add keys without the respective private key).
Your un-encrypted private keys are never shared with our server. My Wallet can again operate in two modes:
- Zero-Trust Mode You can choose to add only your Bitcoin addresses without private keys. This method is potentially more secure as in the event of a security breach of blockchain.info there is no possible way your funds can be compromised. However you are responsible for your own private keys which means you must have your private keys stored somewhere else e.g. A Paper Wallet.
- Private Key Mode (Default) Your private keys will be stored inside your encrypted Wallet. In order to be able to decrypt your wallet you need your password. Your password is not stored on blockchain.info's servers and so in the event of a security breach your keys should still be safe.
Blockchain.info is available as a tor hidden service at https://blockchainbdgpzk.onion/
Your address book is stored inside your encrypted Wallet and cannot be viewed by blockchain.info.
Your password is never shared with our server in any way shape of form.
Email and other personally identifiable information
Any email address, skype username or google talk username you enter will be stored on blockchain.info's servers. We will never share this information with any third parties.
We log a SHA256 hash of the IP address a wallet was created with.
All data we retrieve about your transactions is taken directly from the bitcoin blockchain and uses our publically available api.
Enabling dropbox synchronization allows blockchain.info to read all files in the "Blockchain.info" folder. Your username and password is not shared with us.