Obfuscating data at-transit
A method for obfuscating data at-transit can include receiving a request for communicating data, determining a sequence of data at-transit for a window of time; and providing the sequence of the data at transit for performing communications across interconnect to another component. The described method can be carried out by an obfuscation engine implemented in an electronic system such as within a secure element. A secure element can include a processor and a memory. The obfuscation engine can be part of the processor, part of the memory, or a stand-alone component.
1. A secure element of an electronic system comprising:
a memory; and
a processor, wherein the processor receives a data input and a clock signal input, performs operations according to timing of the clock signal input, and communicates with the memory to read and write data, wherein data traverses between the processor and the memory within the secure element of the electronic system via an interconnect fabric of the secure element, wherein the interconnect fabric comprises metal lines and vias of a data bus between the processor and the memory;
wherein the processor further performs obfuscation operations to protect against side-channel attacks, wherein the obfuscation operations direct the processor to:
determine, for communicating a valid data between the processor and the memory across the interconnect fabric, a sequence of data for a window of time, the sequence of data comprising the valid data and at least one dummy data and at least one null data for the window of time,
wherein the valid data is data used by the electronic system comprising the processor, the dummy data is data that can be discarded by the electronic system, and the null data is a clock cycle during the window of time in which no data is in transit; and
provide the sequence of the data to the memory across the interconnect fabric, whereby the data is obfuscated within the secure element of the electronic system;
wherein the processor further performs operations to:
receive, from the memory, stored data corresponding to each data of the sequence of data;
determine, from the received stored data, a first data corresponding to the valid data and a second data corresponding to a data of the at least one dummy data;
discard the second data; and
provide the first data for use by the electronic system.
2. The secure element of claim 1 , wherein the processor comprises a random number generator for determining the sequence of the data for the window of time.
3. The secure element of claim 1 , wherein the processor comprises a state machine.
4. The secure element of claim 1 , wherein the processor comprises control logic to perform the obfuscation operations.
5. The secure element of claim 1 , wherein the processor executes software that direct the processor to perform the obfuscation operations.
6. The secure element of claim 1 , wherein the obfuscation operations direct the processor to determine, for the communicating of the valid data between the processor and the memory across the interconnect fabric, the sequence of data for the window of time in response to a memory request to read from or write to the memory.
7. The secure element of claim 1 , wherein the sequence of data comprises an order for partial portions of the valid data within the window of time.