Method commit_to_messages

kvac/src/bbdt_2016/setup.rs:92–110

Commit to given messages using the parameters and the given blinding as a Pedersen commitment. `indexed_messages_sorted_by_index` must produce items sorted by unique indices, otherwise, an error will be returned. Eg. if given messages `m_i`, `m_j`, and `m_k` in the iterator, the commitment converts messages to scalars and multiplies them by the parameter curve points: `params.g * blinding + params

(
        &self,
        indexed_messages_sorted_by_index: MI,
        blinding: &'a G::ScalarField,
    )

    /// `params.g * blinding + params.g_vec_i * m_i + params.g_vec_j * m_j + params.g_vec_k * m_k`
    /// Computes using multi-scalar multiplication
    pub fn commit_to_messages<'a, MI>(
        &self,
        indexed_messages_sorted_by_index: MI,
        blinding: &'a G::ScalarField,
    ) -> Result<G, KVACError>
    where
        MI: IntoIterator<Item = (usize, &'a G::ScalarField)>,
    {
        let (bases, scalars): (Vec<_>, Vec<_>) = process_results(
            pair_valid_items_with_slice::<_, _, _, KVACError, _>(
                indexed_messages_sorted_by_index,
                CheckLeft(seq_pairs_satisfy(|a, b| a < b)),
                &self.g_vec,
            ),
            |iter| iter.chain(once((&self.g, blinding))).unzip(),
        )?;

        Ok(G::Group::msm_unchecked(&bases, &scalars).into_affine())
    }

    /// Compute `b = A*{e+x}`
    /// `indexed_messages_sorted_by_index` must produce items sorted by unique indices, otherwise,