Module util

Tools useful for interacting with fancy-garbling.

Note: all number representations in this library are little-endian.

Constants

NPRIMES

Number of primes supported by our library.

PRIMES

Primes used in fancy garbling.

Traits

RngExt

Extra Rng functionality, useful for fancy-garbling.

Functions

as_base_q_u128

Convert x into base q.

as_mixed_radix

Convert x into mixed radix form using the provided radii.

base_modulus_with_width

Generate a CRT modulus that support at least n-bit integers, using provided primes.

base_primes_with_width

Generate the factors of a CRT modulus that support at least n-bit integers, using provided primes.

base_q_add_eq

Add a base q slice ys into xs.

crt

Compute the CRT representation of x with respect to the primes ps.

crt_factor

Compute the CRT representation of x with respect to the factorization of q.

crt_inv

Compute the value x given a list of CRT primes and residues.

crt_inv_factor

Compute the value x given a composite CRT modulus provided by xs.

digits_per_u128

Determine how many mod q digits fit into a u128 (includes the color digit).

factor

Factor using the primes in the global PRIMES array. Fancy garbling only supports composites with small prime factors.

from_base_q

Convert little-endian base q digits into u128.

from_mixed_radix

Convert little-endian mixed radix digits into u128.

generate_deltas

Generate deltas ahead of time for the Garbler.

inv

Invert inp_a mod inp_b.

is_power_of_2

Raise a u16 to a power mod some value. Returns true if x is a power of 2.

modulus_with_nprimes

Primes skipping the modulus 2, which allows certain gadgets. Generate a CRT modulus with n primes.

modulus_with_width

Generate a CRT modulus that support at least n-bit integers, using the built-in PRIMES.

output_tweak

Compute the output tweak for a garbled gate where i is the gate id and k is the value.

primes_with_width

Generate the factors of a CRT modulus that support at least n-bit integers, using the built-in PRIMES.

product

Generate a CRT modulus that support at least n-bit integers, using the built-in PRIMES_SKIP_2 (does not include 2 as a factor). Compute the product of some u16s as a u128.

tweak

Tweak function for a single item.

tweak2

Tweak function for two items.

u128_from_bits

Convert into a u128 from the “bits” as u16. Assumes each “bit” is 0 or 1.

u128_to_bits

Get the bits of a u128 encoded in 128 u16s, which is convenient for the rest of the library, which uses u16 as the base digit type in Wire.