I want to create two different ciphertexts: one with a ring size of 2^10 and 2^9 slots, resulting in a total of two ciphertexts; the other has a ring size of 2^11 and 2^10 slots, resulting in a total of one ciphertext. Is it possible to merge the two ciphertexts with a ring size of 2^10 into a single ciphertext with a ring size of 2^11 through rotation?
I do not think this can be done out of the box using the current version of OpenFHE. You need Ring Switching to do that, and that is not implemented in OpenFHE.
Unless you implement ring switching by yourself, your best option is to instantiate the scheme with the larger ring dimension (2^11) and work with fully packed ciphertexts (2^10 slots) or sparse ciphertexts (2^9 slots) by clearing out any needed slots.
This thread might be useful to you. The authors claim implementing ring switching in their scheme using OpenFHE.
OK, thank you very much.