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  1. efc0edd final gds oasis by Jeff DiCorpo · 1 year, 1 month ago main
  2. 89894c4 Add additional experimental cores, update licensing by Anish · 1 year, 3 months ago
  3. 3202655 Rebuild with changed density requirements by Anish · 1 year, 3 months ago
  4. 6c48ebd Rebuild with slightly tweaked config by Anish · 1 year, 3 months ago
  5. 7832ddd Integration + DRC/timing-clean build of accelerator by Anish · 1 year, 3 months ago

Cryptography Accelerator v2

This is a cryptography accelerator chip for the Skywater MPW-THREE tapeout. It includes an AES256 core (with some key-entropy restrictions to reduce the number of bits in the key), a SHA256 core, a VGA game demo, and some other experimental structures. This includes improved versions of the unsuccessful cores from MPW-ONE.

For documentation on the AES and SHA cores (including the original Chisel source code), see asinghani/crypto-accelerator

Overview

This chip contains 4 major components:

  1. AES128/256 Accelerator

    • Optimized for balance between speed and area, can encrypt or decrypt a 16-byte block in ~20 cycles for AES128 or ~28 cycles for AES256
    • Supports both ECB and CBC modes (CBC is recommended because it is much more secure against certain types of attacks) with no performance penalty for using CBC
    • Has some internal key-entropy limitations since it is meant for experimental use
  2. SHA256 Accelerator

    • Can hash a single 512-bit block in ~66 cycles (and is able to process multiple blocks immediately back-to-back, i.e. when hashing a large file)
  3. VGA Game Demo

    • Contributed by Ethan Polcyn (and then ported to run on the ASIC environment)
    • Consists of a small infinite side-scrolling jumping game (based on the Chromium Browser‘s “No internet”-game), playable using button input from one of the chip’s I/O pins
    • Renders VGA video output at 640x480 through the chip's output pins
  1. Caravel harness/padframe
    • Contains a picorv32 CPU (which is used to interface with the rest of the cores through the Wishbone bus) and the padframe
    • See efabless/caravel for details.