Function encode_masked 

pub fn encode_masked<F, P, NTT, A>(
    params: &FRIParams<F>,
    oracle_index: usize,
    ntt: &NTT,
    message: FieldBuffer<P, FieldSliceData<'_, P>>,
    rng: impl CryptoRng,
    alloc: &A,
) -> MaskedCodeword<P, <A as Allocator>::Vec<P>>
where
    F: BinaryField,
    P: PackedField<Scalar = F>,
    NTT: AdditiveNTT<Field = F> + Sync,
    A: Allocator,

Generates a random mask, interleaves it with the message, and Reed-Solomon encodes.

This is used for zero-knowledge FRI commitments. The function generates a random mask of equal length to the input message, concatenates message || mask as the interleaved message (with log_batch_size = 1), and performs Reed-Solomon encoding. The returned codeword is committed by sending it over a Merkle channel, like encode_interleaved’s.

Arguments

• params - the (possibly batched) FRI parameters.
• oracle_index - the index into FRIParams::input_oracles of the oracle being encoded; its spec must have log_batch_size == 1 and log_msg_len - 1 == message.log_len().
• ntt - the additive NTT for Reed-Solomon encoding
• message - the raw message to encode (not doubled)
• rng - cryptographic RNG for mask generation
• alloc - the allocator the mask, the codeword, and the concatenation temporary are drawn from