A data processing system can use a method of fine-grained address space layout randomization to mitigate the system's vulnerability to return oriented programming security exploits. The randomization can occur at the sub-segment level by randomizing clumps of virtual memory pages. The randomized virtual memory can be presented to processes executing on the system. The mapping between memory spaces can be obfuscated using several obfuscation techniques to prevent the reverse engineering of the shuffled virtual memory mapping.