Rusty Gadgets

This is a rust library for building R1CS gadgets.

Basic example

Here's a simple gadget which computes the cube of a field element:

// Create a gadget which takes a single input, x, and computes its cube.
let mut builder = GadgetBuilder::new();
let x = builder.wire();
let x_squared = builder.product(x.into(), x.into());
let x_cubed = builder.product(x_squared, x.into());
let gadget = builder.build();

// This structure maps wires to their (field element) values. Since x is our input, we will
// assign it a value before executing the gadget. Other wires will be computed by the gadget.
let mut values = values!(x => 5.into());

// Execute the gadget. This returns true iff all constraints were satisfied.
let constraints_satisfied = gadget.execute(&mut values);
assert!(constraints_satisfied);

// Check the result.
assert_eq!(FieldElement::from(125), x_cubed.evaluate(&values));

Non-determinism

This library also supports non-deterministic computations. For a simple example, see GadgetBuilder's inverse method, which is defined in in gadget_builder_arithmetic.rs.

Disclaimer

This code has not been thoroughly reviewed or tested, and should not be used in any production systems.