eLIMInate: a Leakage-focused ISE for Masked Implementation

Ibex core serves as the host core for this work. All the modifications to the original Ibex core (RTL files) are well annotated with // ++ eliminate and // -- eliminate, which facilitates the check by users.

Organisation

├── doc                     - documentation
├── extern                  - external submodules
└── src                     - source code
    ├── area                  - source code for area-optimised version 
    │   ├── coco                - source code for security evaluation with coco     
    │   ├── hw                  - source code for hardware (i.e., ISE implementation)
    │   └── sw                  - source code for software (i.e., micro-benchmarks)
    └── latency               - source code for latency-optimised version
        ├── coco                - source code for security evaluation with coco     
        ├── hw                  - source code for hardware (i.e., ISE implementation)
        └── sw                  - source code for software (i.e., micro-benchmarks)

Usage

Performance evaluation

The performance evaluation of ISE is done with using Ibex Demo System (i.e., extern/ibex-demo-system) which comprises the Ibex core.

• User can choose either a manual modification or using the patch to apply the change to Ibex core:

  • Manual modification

    • Copy all the files in src/[area/latency]/hw/ and replace the original files in extern/ibex-demo-system/vendor/lowrisc_ibex/rtl/.

    • Copy the software micro-benchmark folder src/[area/latency]/sw, and paste it to extern/ibex-demo-system/sw/demo/ and rename it to eliminate.

    • Enter extern/ibex-demo-system/.

    • Edit the file sw/demo/CMakeLists.txt to add add_subdirectory(eliminate).

    • Edit the file sw/CMakeLists.txt to enable the support for assembler code (which is used in micro-benchmarks), i.e., adding enable_language(ASM) and set(CMAKE_ASM_COMPILER riscv32-unknown-elf-gcc).

    • Config the file rtl/system/ibex_demo_system.sv to use a flipflop-based register file (i.e., at line 228 modifying ibex_pkg::RegFileFPGA to ibex_pkg::RegFileFF).

    • For the latency-optimised implementation, edit the file vendor/lowrisc_ibex/ibex_core.core to add - rtl/ibex_lsm_generator.sv and - rtl/keccak_f100_2rounds.sv under the section filesets:files_rtl:files, and edit the file vendor/lowrisc_ibex/ibex_pkg.core to add - rtl/keccak_pkg.sv under the section filesets:files_rtl:files.

  • Using the patch

    • TBA

• Enter extern/ibex-demo-system/ and follow the instructions of README.md to

  • install all the required tools and packages;

  • build the software (i.e., the micro-benchmarks);

  • a) FPGA-option: build FPGA bitstream + program FPGA + load application;

    or

    b) simulation-option: build simulator + run the simulator + get the FST trace.

• Computational correctness test

  a) FPGA-option (recommended for latency-optmised version): view the output of loaded application via screen.

  b) simulation-option (recommended for area-optimised version): view the signals of the collected FST trace in gtkwave.

• Latency measurement

  a) FPGA-option: view the output of loaded application via screen.

  b) simulation-option: view the signals in gtkwave (e.g., with the help of clk_i).

• Hardware overhead measurement

  a) FPGA-option (only): check the vivado GUI report ultilisation.

Security evaluation

The security evaluation (i.e., no leakage stemming from overwriting) of ISE is done by using Coco (i.e., extern/coco-alma and extern/coco-ibex).

• User can choose either a manual modification or using the patch to apply the change to Coco-Ibex core and CoCoAlma:

  • Manual modification

    • Copy all the files in src/[area/latency]/coco/hw/ and replace the original files in extern/coco-ibex/rtl/.

    • Copy the software micro-benchmark folder src/[area/latency]/coco/sw, and paste it to extern/coco-alma/examples/ibex/programs/ and rename it to eliminate.

    • Copy the label file src/[area/latency]/coco/eliminate_label.txt, and paste it to extern/coco-alma/examples/ibex/labels/.

    • Enter extern/coco-alma and follow the instructions of README.md to

      • parse the core
      • compile the micro-benchmark
      • generate the execution trace
      • verify security of custom secure instruction

  • Using the patch

    • TBA