3 ms·
they definitely don’t do this, but in principle they could use homomorphic encryption to do the compression server-side with zero knowledge
by anchpop 5y ago
they definitely don’t do this, but in principle they could use homomorphic encryption to do the compression server-side with zero knowledge
- bawolff 5y agoNot an expert on this so i might be wrong, but pretty sure in homomorphic encryption, you can't run an algorithm that reduces the size of the encrypted payload. Like you could recompress and after decrypting the result is smaller, but that only happens after decrypting. Besides, its also totally impractical.
- sterlind 5y agonope! you can reduce the size. trivial example is just XOR: Enc(A) xor Enc(B) = Enc(A^B).. 2 bits in, one bit out. what you can't do is implement variable-size compression like Huffman trees. if you think about implementing Huffman as a circuit, you have a fixed length output - the worst-case length. you can't read the output any more than you can read the input, so you don't know how much padding you can throw away. therefore it's useless. the same principle applies to running any algorithm that has a dynamic computational complexity. so you can run a Turing machine in FHE, but you won't know when it halts.