Before revision:  We show here that the time evolution of the pandemic doubling time Td(t)  is a reliable  measure of the  efficiency of the Lockdown, case Finding , mobile Tracing (LFT) policy using modern technologies versus the traditional Lockdown Stop and Go (LSG) policy .
After revision:  We show here that the time evolution of the pandemic doubling time Td(t) is a reliable measure of the efficiency of the Lockdown, case Finding , mobile Tracing (LFT) using mandatory mobile contact tracing is much higher than the Lockdown Stop and Go (LSG) policy .