A transaction can only be considered secure and complete once it is included in a block. Bitcoin was designed with one monetary goal foremost in mind: avoiding the dismal fate of previous monetary forms by preventing the evils of debasement. One is a matter of effort; one is a matter of luck. This is something we’re asked everyday! Nowadays all serious Bitcoin mining is performed on ASICs, usually in thermally-regulated data-centers with access to low-cost electricity. The speed at which you mine Bitcoins is measured in hashes per second.