Create a SHA256 tutorial

[zaccherinij]

Winners

See the two winning solutions here and here

Overview

Create a tutorial demonstrating how to develop a homomorphic SHA256 function

Description

Create an FHE program that computes the SHA-256 value over an encrypted input.
Turn it into a tutorial for the documentation, highlighting the process of turning a regular
program into its FHE equivalent. Input text could be fixed-length for Concrete Numpy solution,
while it should be any length for TFHE-rs solution.

Here is a python example of code you could start from:

import hashlib

import concrete.numpy as cnp
import numpy as np

text = (
    b"Lorem ipsum dolor sit amet, consectetur adipiscing elit. "
    b"Curabitur bibendum, urna eu bibendum egestas, neque augue eleifend odio, et sagittis viverra."
)
assert len(text) == 150

hasher = hashlib.sha256()
hasher.update(text)

sample_input = list(text)
expected_output = list(hasher.digest())

def sha256(data):
    # TODO: implement this function
    pass

compiler = cnp.Compiler(sha256, {"data": "encrypted"})
circuit = compiler.compile(
    inputset=[
        np.random.randint(0, 2 ** 8, size=(150,))
        for _ in range(100)
    ],
    configuration=cnp.Configuration(
        enable_unsafe_features=True,
        use_insecure_key_cache=True,
        insecure_key_cache_location=".keys",
    ),
    verbose=True,
)

We expect your PR to comply with the following:

• For Concrete Numpy:
  • Input size is fixed to 150 bytes
  • Create the app examples/sha256.py
  • Create the tutorial docs/tutorial/sha256.{md,ipynb}
• For TFHE-rs:
  • Input size is not fixed
  • Create the app tfhe/examples/sha256.rs
  • Create the tutorial tfhe/docs/tutorial/sha256.md

Library targeted

• Concrete-Numpy
• TFHE-rs

Bounty type

Expert bounty

Reward

Up to €7,500

Related links and references

• Concrete-Numpy documentation
• Concrete-Numpy contribution guide
• TFHE-rs documentation
• TFHE-rs contribution guide

Submission

Apply directly to this bounty by opening an application here.

Questions?

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