eval_fhew_to_ckks_setup: Switch FHEW ciphertexts to a CKKS ciphertext

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

Switch FHEW ciphertexts to a CKKS ciphertext

Description

Packs the messages of a list of FHEW (LWE) ciphertexts into the slots of one CKKS ciphertext (CKKS with real data and Feature$SCHEMESWITCH).

Usage

eval_fhew_to_ckks_setup(cc, cc_lwe, num_slots_ckks = 0L, log_q = 25L)

eval_fhew_to_ckks_key_gen(
  cc,
  key_pair,
  lwesk,
  num_slots = 0L,
  num_ctxts = 0L,
  dim1 = 0L,
  l = 0L
)

eval_fhew_to_ckks(
  cc,
  lwe_ciphertexts,
  num_ctxts = 0L,
  num_slots = 0L,
  p = 4L,
  pmin = 0,
  pmax = 2,
  dim1 = 0L
)

Arguments

cc	A CKKS CryptoContext.
cc_lwe	The BinFHEContext the ciphertexts come from.
num_slots_ckks, num_slots	Integer; number of CKKS slots, 0L (default) for the library's choice.
log_q	Integer; bits of the FHEW ciphertext modulus. Default 25L.
key_pair	The KeyPair of the CKKS context.
lwesk	The LWEPrivateKey of the FHEW context.
num_ctxts	Integer; number of ciphertexts to switch, 0L (default) for all.
dim1	Integer; baby-step dimension of the linear transform, 0L (default) for the library's choice.
l	Integer; level of the linear transform (the C++ argument L). Default 0L.
lwe_ciphertexts	A list of LWECiphertext objects.
p	Integer; plaintext modulus of the FHEW ciphertexts. Default 4L.
pmin, pmax	Numeric; the range of the messages. Defaults 0 and 2.

Details

eval_fhew_to_ckks_setup() records the FHEW context cc_lwe in the CKKS context, and eval_fhew_to_ckks_key_gen() generates the keys of the switch.

The messages are taken modulo p; pmin and pmax give the range they lie in, which sets the interval of the Chebyshev approximation the switch evaluates. The defaults are for bits.

Value

eval_fhew_to_ckks(): a Ciphertext. The others: cc, invisibly.

See Also

eval_ckks_to_fhew()

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