A computing system includes a first security central processing unit (SCPU) of a system-on-a-chip (SOC), the first SCPU configured to execute functions of a first security level. The computing system also includes a second SCPU of the SOC coupled with the first SCPU and coupled with a host processor, the second SCPU configured to execute functions of a second security level less secure than the first security level, and the second SCPU executing functions not executed by the first SCPU.