Has anyone ever seen a tool that tries only a set of keys? Let me explain, imagine you have this key
0x397f5aa7b90de4
What if you want to set the public key of this one 0x5aa7b90de4 and then try all combinations for the first 4 missing characters? as I understand it, no tool exist to scan selected parts of a range, or do they exist?
If you are sure about the last digits of the Privatekey is easy to make some transformations on the public key with arithmetic and work with the result with BSGS.