How can I improve the accuracy of my data? help!

homenc / HElib

HElib is an open-source software library that implements homomorphic encryption. It supports the BGV scheme with bootstrapping and the Approximate Number CKKS scheme. HElib also includes optimizations for efficient homomorphic evaluation, focusing on effective use of ciphertext packing techniques and on the Gentry-Halevi-Smart optimizations.

https://homenc.github.io/HElib

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How can I improve the accuracy of my data? help! #263

Open Ldisi opened 5 years ago

Ldisi commented 5 years ago

I've been using HElib for a while，However, I was stumped by the difficulty of data accuracy. I mean , Helib allows to encrypt positive integer only, but we may need the decimal part in practice. My first thought is to scale the encrypted data with a number , maybe 1000 or bigger . Unfortunately, with the augment of data ,I have to increase p ,which leads to smaller L (Number of multiplication) .The logic is that : decimal -> scale data -> lager p -> smaller L . Do you have any good Suggestions for my problems? Maybe you also have insights in division. Happy for advice from everyone!

justtWu commented 5 years ago

I've got the same problem as yours?Could I ask you some questions? How do I expand the modulus?(if the size of modulus is limit to the precision of long?)

fionser commented 5 years ago

Try using multiple co-prime t, say K > 1 co-prime t.
And encrypt you data with these K keys.
Perform the computation parallel, on the K copies of ciphertexts.
Reconstruct you result from K results using the CRT.