Mirrors the C++ enum SecretKeyDist in
core/lattice/constants-lattice.h.
Value
A named list of 4 integer scalars, each the value of the
OpenFHE C++ enumerator of the same name, naming the distribution
the secret key polynomial is drawn from: GAUSSIAN,
UNIFORM_TERNARY (the default, coefficients uniform on
-1, 0, 1), SPARSE_TERNARY (ternary with a fixed small Hamming
weight) and SPARSE_ENCAPSULATED. Pass an element as the
secret_key_dist argument of CKKSParams(), BFVParams(),
BGVParams() or fhe_context().