Information leak when reconstructing wraps

OpenMined / SyMPC

A SMPC companion library for Syft

MIT License

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Information leak when reconstructing wraps #62

Open gmuraru opened 3 years ago

gmuraru commented 3 years ago

Description

There is a possible information leak when doing public division. At one point we reconstruct the wraps and then we do something like:

value = value - wraps * 4 * (ring_size / 4)

Expected Behavior

The wraps should remain as shares and not be in plaintext

nph4rd commented 3 years ago

I'm taking this on... :)

nph4rd commented 3 years ago

I think it would be a good idea to add direct tests for this part of the code-base. Currently, we only cover it indirectly in the MPC tensor tests. This will allow us to have a better handle of the situation, I think. What is your opinion on this?