Bitcoin Forum

I am trying to built an application that uses the BIP-32. But I am not sure on how to use it.

I have a passphrase with which I generate the Derived Private Key and Derived Public Key. If I share my Derived Public Key with a second wallet will the wallet be able to generate others Derived Public Key from it ? Is it possible ?

And since I have the original Derived Private Key with me, can I see what is happening in the second wallet ?

Also if I loose both the Derived Private Key and Derived Public Key, will I be able to recover my wallets using only the Passphrase ?

No, it is not possible. The second wallet would need to have either the master public key or the master private key in order to generate other addresses.

If you mean can you see the transactions, then yes. This is with any Bitcoin private and public key. If you know one of those, the address can be derived and all transactions can be viewed by anyone.

Yes. So long as you don't lose the master private key, all of your addresses and the corresponding keys can be derived.

Is there any issue in sharing my master public key with a second wallet ?

That other wallet would be able to see every single transaction to and from your wallet. If you give this to another person, then you will lose any transaction privacy. Otherwise, there are no security issues with sharing the master public key.

However, if you share the master public key AND a derived private key, then it is possible for that other person to be able to derive the master private key and thus potentially steal all of the Bitcoin.

Is it possible to share my extended public key to an another wallet using the Bitcoin network ?

No. There is no way to share that over the p2p network.