Exclusive mining was one of the suggestions made in a 2013 paper to which I contributed. We also recommended a rolling active blockchain to help provide a determinate chain size. On Tue, Sep 8, 2020, 4:34 PM jim bell <jdb10987@yahoo.com> wrote:

Decrypt: Researchers Find New Way for Criminals to Launder Money Using Bitcoin.https://decrypt.co/?p=41024