Methods and apparatus of Exclusive OR (XOR) engine in a random access memory device to accelerate cryptographical operations in processors. For example, an integrated circuit memory device enclosed within a single integrated circuit package can include an XOR engine that is coupled with memory units in the random access memory device (e.g., having dynamic random access memory (DRAM) or non-volatile random access memory (NVRAM)). A processor (e.g., System-on-Chip (SoC) or Central Processing Unit (CPU)) can have encryption logic that performs cryptographical operations using XOR operations that are performed by the XOR engine in the random access memory device using the data in the random access memory device.