SchSwchParams: Parameters of scheme switching

In openfhe.R: R Interface to the 'OpenFHE' Fully Homomorphic Encryption Library

Parameters of scheme switching

Description

The parameter object eval_ckks_to_fhew_setup() and eval_scheme_switching_setup() take. SchSwchParams() makes one with the library defaults; the set_ functions on this page change one field each and return the object invisibly, so a parameter object is built step by step as in the OpenFHE examples.

Usage

SchSwchParams(ptr = NULL)

set_security_level_ckks(params, value)

set_security_level_fhew(params, value)

set_arbitrary_function_evaluation(params, value)

set_use_dynamic_mode_fhew(params, value)

set_compute_argmin(params, value)

set_one_hot_encoding(params, value)

set_use_alt_argmin(params, value)

set_num_slots_ckks(params, value)

set_num_values(params, value)

set_ctxt_mod_size_fhew_large_prec(params, value)

set_ctxt_mod_size_fhew_intermed_swch(params, value)

set_b_step_ltr_ckks_to_fhew(params, value)

set_b_step_ltr_fhew_to_ckks(params, value)

set_level_ltr_ckks_to_fhew(params, value)

set_level_ltr_fhew_to_ckks(params, value)

set_ring_dimension(params, value)

set_initial_ckks_modulus(params, value)

set_params_from_ckks_cryptocontext_called(params)

get_security_level_ckks(params)

get_security_level_fhew(params)

get_arbitrary_function_evaluation(params)

get_use_dynamic_mode_fhew(params)

get_compute_argmin(params)

get_one_hot_encoding(params)

get_use_alt_argmin(params)

get_num_slots_ckks(params)

get_num_values(params)

get_ctxt_mod_size_fhew_large_prec(params)

get_ctxt_mod_size_fhew_intermed_swch(params)

get_b_step_ltr_ckks_to_fhew(params)

get_b_step_ltr_fhew_to_ckks(params)

get_level_ltr_ckks_to_fhew(params)

get_level_ltr_fhew_to_ckks(params)

get_ring_dimension(params)

get_initial_ckks_modulus(params)

Arguments

ptr	External pointer (internal use). NULL (default) makes a new parameter object.
params	A SchSwchParams object.
value	The new value of the field: a logical for the five flags, an enum member for the two security levels, a string of decimal digits (or a whole number of at most 2^53) for initial_ckks_modulus, and a non-negative whole number otherwise.

Details

The three fields initial_ckks_modulus, ring_dimension, scaling_mod_size and batch_size describe the CKKS context. The setup functions fill them from the context, so they are not set by hand in ordinary use; set_params_from_ckks_cryptocontext() does the same on request.

The get_ functions return the fields. The library refuses to read a parameter object whose CKKS fields have not been filled, so they work after a setup function or set_params_from_ckks_cryptocontext() has been given the object; format() and print() show every field at any time.

Field	Meaning	Default
security_level_ckks	Security level of the CKKS context, an element of SecurityLevel	HEStd_128_classic
security_level_fhew	Parameter set of the FHEW context, an element of BinFHEParamSet	STD128
arbitrary_function_evaluation	Whether the FHEW context is for arbitrary function evaluation	FALSE
use_dynamic_mode_fhew	Whether the FHEW context uses dynamic gadget bases	FALSE
compute_argmin	Whether the argmin is computed with the minimum (or argmax with the maximum)	FALSE
one_hot_encoding	Whether the argmin is returned one-hot encoded	TRUE
use_alt_argmin	Whether the alternative argmin method is used	FALSE
num_slots_ckks	Number of CKKS slots to switch	0
num_values	Number of values to switch	0
ctxt_mod_size_fhew_large_prec	Bits of the large-precision FHEW ciphertext modulus	25
ctxt_mod_size_fhew_intermed_swch	Bits of the intermediate modulus of the switch	27
b_step_ltr_ckks_to_fhew	Baby-step of the linear transform from CKKS to FHEW	0
b_step_ltr_fhew_to_ckks	Baby-step of the linear transform from FHEW to CKKS	0
level_ltr_ckks_to_fhew	Level of the linear transform from CKKS to FHEW	1
level_ltr_fhew_to_ckks	Level of the linear transform from FHEW to CKKS	0

Value

SchSwchParams(): an S7 object of class SchSwchParams, inheriting from OpenFHEObject. The set_ functions: params, invisibly. The get_ functions: the value of the field, a string of decimal digits for initial_ckks_modulus.

Examples

params <- SchSwchParams()
set_security_level_ckks(params, SecurityLevel$HEStd_NotSet)
set_security_level_fhew(params, BinFHEParamSet$TOY)
set_num_slots_ckks(params, 16L)
params

openfhe.R documentation built on Nov. 13, 2026, 5:07 p.m.