Multi parameters

This document explains the implications and configuration of multi parameters in Concrete.

In Concrete, integers are encrypted and processed based on a set of cryptographic parameters. By default, the Concrete optimizer selects multiple sets of these parameters, which may not be optimal for every use case. In such cases, you can choose to use mono parameters instead.

When multi parameters are enabled, the optimizer selects a different set of parameters for each bit-width in the circuit. This approach has several implications:

• Faster execution in general

• Slower key generation

• Larger keys

• Larger memory usage during execution

When enabled, you can control the level of circuit partitioning by setting the multi_parameter_strategy as described in configuration.

To disable multi parameters, use parameter_selection_strategy=fhe.ParameterSelectionStrategy.MONO configuration option.