I'm trying to use the Microsoft SEAL library in order to do Matrix multiplication. That's why I'm trying to find a way to compute the Dot Product of 2 vectors.
My issue is that the CKKS encoder in SEAL encodes entire vectors. So if I had a 2D vector of floats I get a 1D vector of Plaintext (and then a 1D vector of Ciphertext after encryption).
The operations that I am able to do are: addition, component-wise multiplication, exponential, and rotation. In order to do a dot product of vectors I need to multiply the components of the first vector by the components of the second vector and sum them up. If I want to multiply 2 matrices, I can transpose the second matrix and multiply the rows together but I am unable to compute the sum of the elements inside the Ciphertext. Is it possible to get the sum of those elements in the Ciphertext? Should I change my approach?