System and method for context switching of a cryptographic engine

A device, the device comprising:

• a component forming input data;
• a cryptographic system, the cryptographic system receiving the formed input data from the component, the cryptographic system comprising
• a memory, the memory storing a first cryptographic datum;
• a processing unit, the processing unit
• (a) executing a cryptographic algorithm using a second cryptographic datum and the received input data to form output data;
• (b) determining if a context switch command is received, the context switch command including a request to change a processing state of the processing unit;
• (c) receiving the first cryptographic datum from the memory if the context switch command is received;
• (d) sending the second cryptographic datum to the memory if the context switch command is received before replacing the second cryptographic datum with the first cryptographic datum;
• (e) replacing the second cryptographic datum with the first cryptographic datum if the context switch command is received;
• and
• (f) repeating (a)-(e);
• and
• a context switch controller, the context switch controller sending the context switch command to the processing unit;
• and
• an RF controller configured to receive communications from a plurality of communications channels, the RF controller identifying an event based on the received communications, the RF controller further configured to determine that the event caused a context change for the cryptographic system, the RF controller further configured to send a command to the context switch controller including a context switch.

A method of implementing cryptographic functions designed to protect data, the method comprising:

• providing a processing unit and an RF controller configured to receive communications from a plurality of communications channels;
• using the RF controller to process the communications to determine to send a context switch command to the processing unit;
• executing a cryptographic algorithm at the processing unit using a second cryptographic datum and input data to form output data, the input data received from a component;
• determining if the context switch command is received from the RF controller, the context switch command including a request to change a processing state of the cryptographic algorithm;
• receiving a first cryptographic datum from a memory if the context switch command is received;
• (d) sending the second cryptographic datum to the memory if the context switch command is received before replacing the second cryptographic datum with the first cryptographic datum;
• and
• replacing the second cryptographic datum with the first cryptographic datum if the context switch command is received.