Mirrors the C++ enum KEYGEN_MODE in binfhe/binfhe-constants.h.
Value
A named list of 2 integer scalars, each the value of the
OpenFHE C++ enumerator of the same name: SYM_ENCRYPT generates
only the material needed for symmetric-key encryption, while
PUB_ENCRYPT additionally generates a public key. Pass an element
as the keygen_mode argument of bin_bt_key_gen().