it is about how to use asymmetric encryption for license keys), the link I gave for RBL explains how DNS blacklists work. You only have to perform one DNS lookup to figure out if a license has been blacklisted, that
Record Lookup Unit 7064 Crowner Drive Lansing, Michigan 48918 Minnesota Minnesota Department of Public Safety Driver and Vehicle Services 445 Minnesota Street St. Paul, MN 55101 Mississippi Mississippi Department of Public Safety Driver Records Branch PO Box 958 Jackson, MS 39205 ...