rsa-xcel

Two implementations of RSA hardware accelerators, meant to be tightly coupled to a processor for speeding up encryption and decryption computations significantly. This represents a final project for Cornell University's ECE 5745: Complex Digital ASIC Design.

Prerequisites

The hardware is implemented in Verilog, and is simulated using Verilator. Specifically, the project is verified using PyMTL3, a Python framework for hardware modeling and testing.

Algorithms

Overall, the project details 4 different algorithms

• "Naive" RSA implementing modular exponentiation via exponentiation by squaring
• RSA implemented using Montgomery multiplication, operating on values in n-residue format.
• "Naive" RSA using a modular exponentiation hardware accelerator
• Montgomery RSA using a modular exponentiation hardware accelerator operating on n-residue values

This hardware is meant to be coupled with a RISC-V processor; the code for this has been removed, as it is part of the ECE 4750/5745 courses at Cornell University, but is discussed in the accompanying report. Overall, we can show that, compared to the naive software implementation, our hardware accelerator using Montgomery multiplication and n-residue values can achieve a speedup of 20.85 for encryption, and 34.82 for decryption, largely due to the differences in the properties of the data (with various other tradeoffs in area and energy).

Verification

All of our high-level algorithms were implemented in Python, and are contained in algo (this code was similarly implemented in C to run on the processor, but has similarly been removed). Our algorithms are compared not only against each other, but against Python's RSA module, which serves as our golden model

Our hardware verification is done through PyMTL3. Here, we can re-use our functional-level models, as well as Python's RSA module, and verify our modules through comparison on a representative set of workloads. All individual modules are unit-tested, and tests are re-used across our two accelerators due to their modularity in having the same interface.

To verify the modules, create a build directory, and use pytest as part of PyMTL3 to test both the naive and Montgomery accelerators:

mkdir hw/build
cd hw/build
pytest ../rsa_xcel_naive ../rsa_xcel_mont --verbose

Results

All of the results are collected and summarized in the report for ECE 5745