[PoC] run SQL over ciphertext

Hi all,

We have developed an extension, allowing PostgreSQL to run queries over encrypted data. This functionality is achieved via user-defined functions that extend encrypted data types and support commonly used expression operations. Our tests validated its effectiveness with TPC-C and TPC-H benchmarks. You may find the code here: https://github.com/SJTU-IPADS/HEDB.

This PoC is a reimplementation fork while collaborating with a cloud database company; the aim is to enable their DBAs to manage databases without the risk of data leaks, meeting the requirements of laws such as GDPR.

I am wondering if anyone thinks this is a nice feature. If so, I am curious about the steps to further it mature and potentially have it incorporated as a part of PostgreSQL contrib.

Best regards,
Mingyu Li