Make a CKKS packed plaintext from real numbers — make_ckks_packed

Encode a real-valued numeric vector as a CKKS packed plaintext. The result is an unencrypted Plaintext object that can then be passed to encrypt().

Usage

make_ckks_packed_plaintext(
  cc,
  values,
  noise_scale_deg = 1L,
  level = 0L,
  params = NULL,
  slots = 0L
)

Arguments

cc: A CryptoContext built with scheme = "CKKS".
values: A numeric vector to pack. Length must not exceed slots (or batch_size / 2 when slots is left at 0L).
noise_scale_deg: Integer degree of the initial scaling factor applied to the encoded plaintext, expressed as a power of the scheme's scaling factor. Defaults to 1L, meaning "scale by the base scaling factor once", which is the value every current vignette implicitly uses. Setting noise_scale_deg = 2L encodes at scaling factor squared, which is occasionally useful when the plaintext is about to be subtracted from a ciphertext that has already been rescaled once and the two noise levels must agree. Under FLEXIBLEAUTO scaling the scheme's auto-rescale logic overrides this argument at context-generation time — see discovery D011 — so this parameter is only meaningful under FIXEDMANUAL. Couples tightly to level: a plaintext at (noise_scale_deg = k, level = L) may only interact with ciphertexts at the same (k, L).
level: Integer target encryption level of the encoded plaintext. Defaults to 0L, meaning "encode at the fresh level, matching a just-encrypted ciphertext". When performing an operation between an encoded plaintext and a ciphertext that has already been rescaled L times, the plaintext must be encoded at level = L so the two sit at the same level of the modulus chain; otherwise the evaluator will silently mismatch or error depending on the scheme variant. The canonical case for setting this is encoding a constant vector for use inside a deep CKKS circuit, not for fresh-input computation. Couples to noise_scale_deg and to the multiplicative depth of the crypto context, which bounds the maximum valid level.
params: Advanced. An ElementParams object to encode against, or NULL to use the cryptocontext's own parameters at the chosen level. Defaults to NULL, which is the only value any current vignette or test uses. There is no R-side way to construct a fresh ElementParams (only to wrap one returned by get_element_params(cc)), so in practice the argument is accepted for surface parity with openfhe-python but is normally left at its default.
slots: Integer number of CKKS slots to pack into. Defaults to 0L, which is the upstream sentinel for "use the batch_size set on the context's params". Setting slots to a smaller power of two produces a plaintext that leaves the upper half of the packing register zero, which the evaluator exploits to reduce rotation cost in algorithms like eval_sum. The value must be a power of two and must not exceed batch_size. The natural time to set this is when you have a short input vector and rotations dominate the circuit cost, as in the CKKS-inner-product idiom; the natural time to leave it at 0L is when you are encoding a full-width vector.

Value

A Plaintext.