TrustZone provides H/W enforced isolation between trusted world and normal world, as depicted in the left image here by the solid blue line. TrustZone also permits normal world access of trusted world assets via secure authenticated (legal) APIs, illustrated by the two horizontal white lines crossing the solid blue line. However, TrustZone is only one part of the puzzle. CryptoCell-312 adds more security to TrustZone, including encryption, lifecycle management, debug authentication, cryptography, and true random number generator for “challenge and response” authentication.