jaxite 0.0.2

A Homomorphic Encryption implementation (CGGI) written in JAX

Jaxite

Jaxite is a fully homomorphic encryption backend targeting TPUs and GPUs, written in JAX.

It implements the CGGI cryptosystem with some optimizations, and is a supported backend for Google's FHE compiler.

Quick start

jaxite_bool

A program that shows how to use the jaxite_bool boolean gate API.

from jaxite import jaxite_bool

bool_params = jaxite_bool.bool_params

lwe_rng = bool_params.get_lwe_rng_for_128_bit_security(seed=1)
rlwe_rng = bool_params.get_rlwe_rng_for_128_bit_security(seed=1)
params = bool_params.get_params_for_128_bit_security()
cks = jaxite_bool.ClientKeySet(
    params,
    lwe_rng=lwe_rng,
    rlwe_rng=rlwe_rng,
)
sks = jaxite_bool.ServerKeySet(
    cks,
    params,
    lwe_rng=lwe_rng,
    rlwe_rng=rlwe_rng,
    bootstrap_callback=callback,
)

ct_true = jaxite_bool.encrypt(True, cks, lwe_rng)
ct_false = jaxite_bool.encrypt(False, cks, lwe_rng)

not_false = jaxite_bool.not_(ct_false, params)
or_false = jaxite_bool.or_(not_false, ct_false, sks, params)
and_true = jaxite_bool.and_(or_false, ct_true, sks, params)
xor_true = jaxite_bool.xor_(and_true, ct_true, sks, params)
actual = jaxite_bool.decrypt(xor_true, cks)

expected = (((not False) or False) and True) != True
assert actual == expected

Jaxite also supports higher-bit-width gates, which are called look-up tables (LUTs).

For example, this function is an 8-bit adder consisting entirely of lut3 gates.

def add_i8(
    x: List[types.LweCiphertext],
    y: List[types.LweCiphertext],
    sks: jaxite_bool.ServerKeySet,
    params: jaxite_bool.Parameters) -> List[types.LweCiphertext]:
  temp_nodes: Dict[int, types.LweCiphertext] = {}
  false = jaxite_bool.constant(False, params)
  out = [None] * 8
  temp_nodes[0] = jaxite_bool.lut3(x[0], y[0], false, 8, sks, params)
  temp_nodes[1] = jaxite_bool.lut3(temp_nodes[0], x[1], y[1], 23, sks, params)
  temp_nodes[2] = jaxite_bool.lut3(temp_nodes[1], x[2], y[2], 43, sks, params)
  temp_nodes[3] = jaxite_bool.lut3(temp_nodes[2], x[3], y[3], 43, sks, params)
  temp_nodes[4] = jaxite_bool.lut3(temp_nodes[3], x[4], y[4], 43, sks, params)
  temp_nodes[5] = jaxite_bool.lut3(temp_nodes[4], x[5], y[5], 43, sks, params)
  temp_nodes[6] = jaxite_bool.lut3(temp_nodes[5], x[6], y[6], 43, sks, params)
  out[0] = jaxite_bool.lut3(x[0], y[0], false, 6, sks, params)
  out[1] = jaxite_bool.lut3(temp_nodes[0], x[1], y[1], 150, sks, params)
  out[2] = jaxite_bool.lut3(temp_nodes[1], x[2], y[2], 105, sks, params)
  out[3] = jaxite_bool.lut3(temp_nodes[2], x[3], y[3], 105, sks, params)
  out[4] = jaxite_bool.lut3(temp_nodes[3], x[4], y[4], 105, sks, params)
  out[5] = jaxite_bool.lut3(temp_nodes[4], x[5], y[5], 105, sks, params)
  out[6] = jaxite_bool.lut3(temp_nodes[5], x[6], y[6], 105, sks, params)
  out[7] = jaxite_bool.lut3(temp_nodes[6], x[7], y[7], 105, sks, params)
  return out

On a platform with parallelism, jaxite uses JAX's pmap API to allow parallel evaluation of gates that have no interdependencies. E.g., the last eight gate operations of the i8 adder above could be rewritten as

 inputs = [
    (x[0], y[0], false, 6),            # out[0]
    (temp_nodes[0], x[1], y[1], 150),  # out[1]
    (temp_nodes[1], x[2], y[2], 105),  # out[2]
    (temp_nodes[2], x[3], y[3], 105),  # out[3]
    (temp_nodes[3], x[4], y[4], 105),  # out[4]
    (temp_nodes[4], x[5], y[5], 105),  # out[5]
    (temp_nodes[5], x[6], y[6], 105),  # out[6]
    (temp_nodes[6], x[7], y[7], 105),  # out[7]
  ]
  outputs = jaxite_bool.pmap_lut3(inputs, sks, params)
  return outputs

These circuits were generated with the jaxite support in Google's Fully Homomorphic Encryption Transpiler project, see transpiler/jaxite in that project for instructions.

Contributing

See CONTRIBUTING.md for details.

License

Apache 2.0; see LICENSE for details.

Disclaimer

This project is not an official Google project. It is not supported by Google and Google specifically disclaims all warranties as to its quality, merchantability, or fitness for a particular purpose.