Timing attack is a class of side-channel attacks that aims to
leak secret information based on the time it takes to perform different
operations. The biggest advantage of a timing attack is that it does not
require sophisticated or expensive equipment to be carried out. Side Channels
on FHE schemes have been reported on the client side which has the secret key.
But the present project aims to delve into the counter intuitive question,
can an analysis be performed on the server end which ideally has no information
of the secret key. In this
report, we investigate when homomorphic operations are performed on the ciphertexts
stored in the server, can timing reveal information of the error used to mask the
ciphertexts? Finally, can this be utilized to determine the
secret key of the ciphering technique?
A short review can be found here, summarizing the existing work: here.
The work is ongoing, and we will keep on adding more materials and thoughts.