Function multi_exponentiate_montgomery_form_slice 

pub fn multi_exponentiate_montgomery_form_slice<const LIMBS: usize, const RHS_LIMBS: usize, const VARTIME: bool>(
    bases_and_exponents: &[(Uint<LIMBS>, Uint<RHS_LIMBS>)],
    exponent_bits: u32,
    params: &FixedMontyParams<LIMBS>,
) -> Uint<LIMBS>

Performs modular multi-exponentiation using Montgomery’s ladder. exponent_bits represents the number of bits to take into account for the exponent.

See: Straus, E. G. Problems and solutions: Addition chains of vectors. American Mathematical Monthly 71 (1964), 806–808.

NOTE: this value is leaked in the time pattern.