1.) Is it possible to recover part of private key, when I have valid address?
For example:
let's say one of my paper wallet is partialy destroyed, and I have lost 5 or more characters from private, like:
pub: 1DrqrF3JEYB9TXWymz4zGoEzM5i75JMLFB
priv: L3Wji4b***4Po3vo2gmi42Y2kbbxtnpAfQ5wJx11BgNr****8v3Q
Would be EXTREMALY usefull for paperwallet users!
Regards.
If you know the public key (not the address) and the first ~ 180 bits of the private key, it is possible to retrieve the other 70 / 80 bits using smarter ways than brute force attack.