3 ms·

I'm not sure who wrote this, but....ohhh boy: https://en.m.wikipedia.org/wiki/Homomorphic_encryption https://en.m.wikipedia.org/wiki/Homomorphic_encryption I'

• verdverm 5y ago
  There is a TF package for learning on encrypted data. Not familiar with the details or encryption algos supported. https://github.com/tf-encrypted/tf-encrypted https://github.com/tf-encrypted/tf-encrypted Homomorphic means the algebra is the same on both sides of the encryption, so this would be one of the types of encryption where this is possible.
  • kop316 5y ago
    > learning on encrypted data In reading through the readme, its data the user encrypts (which is a goal of homomorphic encryption), not learning on data of someone else that is encrypted. Assuming data us properly encrypted, it is indistinguishable from noise, so I don't see how someone can learn on someone else's encrypted data.
    • verdverm 5y ago
      Homomorphic encrypted cyphertext cannot be decrypted without the private key, but you can do math on it and get the encrypted result, which you still cannot decrypt. However, you can still do maths and make predictions. It's far more expensive, computationally speaking, but can be used for many things. It's all about homologies, understand what that means to understand why this is possible while still having good security and doing encryption correctly.
      • kop316 5y ago
        That makes the VERY BIG assumption that you know a priori what the ciphertext is in real time, just FYI.
• g_p 5y ago
  Agreed that homomorphic is a pretty absurd leap in the article. Shared my thoughts on what it could be in another comment. With regard to FHE, I'm familiar with the concept in abstract, but this article and the comments made me wonder how traditional definitions of security work in a homomorphic world. Specifically, do we assume under FHE that the computation provider has no a-priori information beyond basic structure of the values contained? (i.e. do you need to exchange some key to the party who should be able to do computation, even if this key can't decrypt the ciphertext to plaintext?) Assuming this isn't the case, do we retain classical definitions of security (the ciphertext leaks no information about plaintext; large collections of ciphertexts similarly reveal no information about plaintexts, or the similarity or difference between any two plaintexts) under FHE? It seems if this holds true, FHE mathematically can't do this, as it would require revealing information from a ciphertext that means it is no longer effectively encrypted, hence it isn't homomorphic.
  • kop316 5y ago
    My understanding is homomorphic encryption is extremely useful if you want to do computation on someone else's server with data that you don't want to reveal. However, in practice, you reveal some information about the data if you do computations in it. One notional example is if you see a bunch of XORs in data. You may not know what the data is, but if you see a bunch of XORs, you can make an educated guess that some sort of cipher operation occurs (as XOR is used heavily in it).
    • verdverm 5y ago
      There are other ways to leak data when you train ML on it for example. (many example inputs really :)
      • kop316 5y ago
        That's fair, I just wanted to give a single example!