Modules

Modules are still experimental. They are only compatible with composition, which means the outputs of every functions can be used directly as inputs for other functions. The crypto-parameters used in this mode are large and thus, the execution is likely to slow.

In some cases, deploying a server that can execute different functions is useful. Concrete can compile FHE modules, that can contain many different functions to execute at once. All the functions are compiled in a single step and can be deployed with the same artifacts. Here is an example:

from concrete import fhe

@fhe.module()
class MyModule:
    @fhe.function({"x": "encrypted"})
    def inc(x):
        return x + 1 % 20

    @fhe.function({"x": "encrypted"})
    def dec(x):
        return x - 1 % 20

You can compile the FHE module MyModule using the compile method. To do that, you need to provide a dictionnary of input sets for every function:

inputset = list(range(20))
my_module = MyModule.compile({"inc": inputset, "dec": inputset})

Note that here we can see a current limitation of modules: The configuration must use the parameter_selection_strategy of v0, and activate the composable flag.

After the module has been compiled, we can encrypt and call the different functions in the following way:

x = 5
x_enc = my_module.inc.encrypt(x)
x_inc_enc = my_module.inc.run(x_enc)
x_inc = my_module.inc.decrypt(x_inc_enc)
assert x_inc == 6

x_inc_dec_enc = my_module.dec.run(x_inc_enc)
x_inc_dec = my_module.dec.decrypt(x_inc_dec_enc)
assert x_inc_dec == 5

for _ in range(10):
    x_enc = my_module.inc.run(x_enc)
x_dec = my_module.inc.decrypt(x_enc)
assert x_dec == 15