Mass data (the contents of arrays, large data structures, linked data structures and similar data structures stored in memory) are common targets for attack. The invention presents a method and system of protecting mass data by mapping virtual addresses onto randomly or pseudo-randomly selected actual addresses. This mapping distributes data values throughout the memory so an attacker cannot locate the data he is seeking, or identify patterns which might allow him to obtain information about his target (such as how the software operates, encryption keys, biometric data or passwords stored therein, or algorithms it uses). Additional layers of protection are described, as well as efficient techniques for generating the necessary transforms to perform the invention.