Proxy re encryption with 3rd party encrypting message about ecc HOT 3 CLOSED

Hi @perki, I'm glad you are giving this library a try. You are right, the primitives in this "schema1" are not adequate for your use case, it does not scale.

I think your problem can be solved with an additional clever trick on the keys of contributors and recipients, and I believe this is solved in the paper "Cryptographically Enforced Orthogonal Access Control at Scale" by Bob Wall and Patric Walsh.

...allows the decision about the groups to which to encrypt a piece of data to be made independently and asynchronously from the decision about who belongs to a group and can therefore decrypt the data.

That's the foundation of their product of group management and PRE.

Still, there is a cost when an entity is added or removed from the group since keys need to be regenerated iirc.

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Hello @aldenml,

Thank you for your answer.
My first successful implementation is with Ironcore's library from Bob Wall and Patric Walsh. Now I start testing others PRE flavors such as your implementation.

For my use case, I don't need to "add" / "remove" entities from a group.
But I need anyone to able to contribute.

A not fully end-end to encryption, but could be acceptable for my use case, is then to let the proxy encrypt plain text messages with A pk. Then A could generate a reEncryption key (implying that A knows the proxy's secret signing).

Thanks again and kind regards,
Pierre-Mikael

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Feel free to re-open if you want to continue the thread

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