An apparatus and a method for measuring the security strength of a lock pattern applied to a terminal device are disclosed. The disclosed apparatus may include: a CCI monitoring part configured to read cache coherence information associated with a touch made over a multiple number of points implementing a lock pattern inputted by a user from a CCI (cache coherence interconnect); a computation part configured to compute a multiple number of similar lock pattern candidates by using the read cache coherence information; and a measurement part configured to measure the security strength of the inputted lock pattern by using the multiple number of similar lock pattern candidates.