1. A secure protection method, executed by a processor, comprising: performing a first security checking before or after executing a first instruction according to an instruction security attribute (ISA) of the first instruction and a security attribute (SA) of an operational event (OE), wherein the OE is generated as a side effect when the processor fetches or executes the first instruction, or generated as a monitoring result on the first instruction, or generated in response to an external input of the processor; and ignoring the OE, deferring the OE, or raising a security exception when the first security checking fails.