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j2kunlast Friday at 3:14 PM1 replyview on HN

Your assumption that operations leak info is just not correct. RSA has homomorphic properties (you can multiply two RSA ciphertexts and get the encrypted product of the plaintext), just not enough to enable general purpose computation.


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JohnFenlast Friday at 3:21 PM

> Your assumption that operations leak info is just not correct.

My assumption is that you're right, that my assumption is incorrect. What I'm trying to do is understand why it's incorrect.

It's not just about operations leaking info, though, it's also an issue that, intuitively, leaving enough underlying structure in the encrypted form of the data to allow for this implies that the encrypted form is weaker. I'm also trying to understand how that intuition is wrong.

Edit: OK, The jeremykun link this comment provided gave me a little more clarity: https://news.ycombinator.com/item?id=44602472

I still don't adequately understand, but it does give me a little bit of a handle my brain can grab onto. As I understand it right now, HME is a weaker form of encryption, but perhaps still strong enough to be a worthwhile tradeoff for the use cases being discussed.

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