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A comment on Fully Homomorphic Encryption and the Dawn of a Truly Private Internet. Parent comment

Re:Fully Homomorphic Encryption and the Dawn of a Truly Priv... by Tryk on Friday July 18, 2025 @07:36AM (#44603569)
When comparing two ciphertexts A,B a FHE sorting function will output a sorted pair of two new ciphertexts:

E.g. FHE_SORT(A,B) -> (X,Y)

where Dec(X)<Dec(Y)

But without decoding, there's no way of knowing whether X (or Y) comes from A or B.

Source: II. D of https://eprint.iacr.org/2015/995.pdf

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Re:Fully Homomorphic Encryption and the Dawn of a Truly Priv... by dcow on Friday July 18, 2025 @10:11AM (#44604844)
It’s not that simple. The client has to send the server the comparison function.

To do anything practical the server usually needs to provide the client with gigabytes of per-client-key encrypted seed data.

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