You want the private key of the addresses that are not yours? If this is how bitcoin is, everyone will be spending everyone's coins and which means bitcoin is not safe, but bitcoin is safe. You can not generate private key from public key or address.
but, this author alredy found the private key how ? 
https://www.mdpi.com/2227-7390/8/10/1645see this https://www.blockchain.com/explorer/addresses/btc/1B5USZh6fc2hvw2yW9YaVF75sJLcLQ4wCt some btc move
please explain ,how to get this 1B5USZh6fc2hvw2yW9YaVF75sJLcLQ4wCt privatekey
read this para 3. A Small Subgroup Attack this link https://www.mdpi.com/2227-7390/8/10/1645
explain me