@ -376,14 +376,12 @@ pub trait CycleFoldConfig {
/// Public inputs length for the CycleFoldCircuit.
/// * For Nova this is: `|[r, p1.x,y, p2.x,y, p3.x,y]|`
/// * In general, `|[r * (n_points-1) , (p_i.x,y)*n_points, p_folded.x,y]|`.
/// * In general, `|[r, (p_i.x,y)*n_points, p_folded.x,y]|`.
///
/// Thus, `IO_LEN` is:
/// `RANDOMNESS_BIT_LENGTH / FIELD_CAPACITY * (N_INPUT_POINTS - 1) + 2 * N_INPUT_POINTS + 2`
/// `RANDOMNESS_BIT_LENGTH / FIELD_CAPACITY + 2 * N_INPUT_POINTS + 2`
const IO_LEN : usize = {
Self ::RANDOMNESS_BIT_LENGTH . div_ceil ( Self ::FIELD_CAPACITY ) * ( Self ::N_INPUT_POINTS - 1 )
+ 2 * Self ::N_INPUT_POINTS
+ 2
Self ::RANDOMNESS_BIT_LENGTH . div_ceil ( Self ::FIELD_CAPACITY ) + 2 * Self ::N_INPUT_POINTS + 2
} ;
type F : Field ;
@ -396,10 +394,9 @@ pub trait CycleFoldConfig {
#[ derive(Debug, Clone) ]
pub struct CycleFoldCircuit < CFG : CycleFoldConfig , GC : CurveVar < CFG ::C , CFG ::F > > {
pub _gc : PhantomData < GC > ,
/// r_bits is a vector containing the r_bits, one for each point except for the first one. They
/// are used for the scalar multiplication of the points. The r_bits are the bit
/// representation of each power of r (in Fr, while the CycleFoldCircuit is in Fq).
pub r_bits : Option < Vec < Vec < bool > > > ,
/// r_bits is the bit representation of the r whose powers are used in the
/// random-linear-combination inside the CycleFoldCircuit
pub r_bits : Option < Vec < bool > > ,
/// points to be folded in the CycleFoldCircuit
pub points : Option < Vec < CFG ::C > > ,
/// public inputs (cf_u_{i+1}.x)
@ -426,18 +423,11 @@ where
for < 'a > & 'a GC : GroupOpsBounds < 'a , CFG ::C , GC > ,
{
fn generate_constraints ( self , cs : ConstraintSystemRef < CFG ::F > ) -> Result < ( ) , SynthesisError > {
let r_bits : Vec < Vec < Boolean < CFG ::F > > > = self
. r_bits
// n_points-1, bcs is one for each point except for the first one
. unwrap_or ( vec ! [
vec ! [ false ; CFG ::RANDOMNESS_BIT_LENGTH ] ;
CFG ::N_INPUT_POINTS - 1
] )
. iter ( )
. map ( | r_bits_i | {
Vec ::< Boolean < CFG ::F > > ::new_witness ( cs . clone ( ) , | | Ok ( r_bits_i . clone ( ) ) )
} )
. collect ::< Result < _ , _ > > ( ) ? ;
let r_bits = Vec ::< Boolean < CFG ::F > > ::new_witness ( cs . clone ( ) , | | {
Ok ( self
. r_bits
. unwrap_or ( vec ! [ false ; CFG ::RANDOMNESS_BIT_LENGTH ] ) )
} ) ? ;
let points = Vec ::< GC > ::new_witness ( cs . clone ( ) , | | {
Ok ( self
. points
@ -447,10 +437,7 @@ where
#[ cfg(test) ]
{
assert_eq ! ( CFG ::N_INPUT_POINTS , points . len ( ) ) ;
assert_eq ! ( CFG ::N_INPUT_POINTS - 1 , r_bits . len ( ) ) ;
for r_bits_i in & r_bits {
assert_eq ! ( r_bits_i . len ( ) , CFG ::RANDOMNESS_BIT_LENGTH ) ;
}
assert_eq ! ( CFG ::RANDOMNESS_BIT_LENGTH , r_bits . len ( ) ) ;
}
// Fold the original points of the instances natively in CycleFold.
@ -458,11 +445,13 @@ where
// - for the cmW we're computing: U_i1.cmW = U_i.cmW + r * u_i.cmW
// - for the cmE we're computing: U_i1.cmE = U_i.cmE + r * cmT + r^2 * u_i.cmE, where u_i.cmE
// is assumed to be 0, so, U_i1.cmE = U_i.cmE + r * cmT
let mut p_folded : GC = points [ 0 ] . clone ( ) ;
// iter over n_points-1 because the first point is not multiplied by r^i (it is multiplied
// by r^0=1)
for i in 0 . . CFG ::N_INPUT_POINTS - 1 {
p_folded + = points [ i + 1 ] . scalar_mul_le ( r_bits [ i ] . iter ( ) ) ? ;
// We want to compute
// P_folded = p_0 + r * P_1 + r^2 * P_2 + r^3 * P_3 + ... + r^{n-2} * P_{n-2} + r^{n-1} * P_{n-1}
// so in order to do it more efficiently (less constraints) we do
// P_folded = (((P_{n-1} * r + P_{n-2}) * r + P_{n-3})... ) * r + P_0
let mut p_folded : GC = points [ CFG ::N_INPUT_POINTS - 1 ] . clone ( ) ;
for i in ( 0 . . CFG ::N_INPUT_POINTS - 1 ) . rev ( ) {
p_folded = p_folded . scalar_mul_le ( r_bits . iter ( ) ) ? + points [ i ] . clone ( ) ;
}
let x = Vec ::< FpVar < CFG ::F > > ::new_input ( cs . clone ( ) , | | {
@ -474,24 +463,23 @@ where
// Check that the points coordinates are placed as the public input x:
// In Nova, this is: x == [r, p1, p2, p3] (wheere p3 is the p_folded).
// In multifolding schemes such as HyperNova, this is:
// computed_x = [r_0, r_1, r_2, ..., r_n , p_0, p_1, p_2, ..., p_n, p_folded],
// computed_x = [r, p_0, p_1, p_2, ..., p_n, p_folded],
// where each p_i is in fact p_i.to_constraint_field()
let computed_x : Vec < FpVar < CFG ::F > > = r_bits
let r_fp = Boolean ::le_bits_to_fp_var ( & r_bits ) ? ;
let points_aux : Vec < FpVar < CFG ::F > > = points
. iter ( )
. map ( | r_bits_i | {
r_bits_i
. chunks ( CFG ::FIELD_CAPACITY )
. map ( Boolean ::le_bits_to_fp_var )
. collect ::< Result < Vec < _ > , _ > > ( )
} )
. chain (
points
. iter ( )
. chain ( & [ p_folded ] )
. map ( | p_i | Ok ( p_i . to_constraint_field ( ) ? [ . . 2 ] . to_vec ( ) ) ) ,
)
. collect ::< Result < Vec < _ > , _ > > ( ) ?
. concat ( ) ;
. map ( | p_i | Ok ( p_i . to_constraint_field ( ) ? [ . . 2 ] . to_vec ( ) ) )
. collect ::< Result < Vec < _ > , SynthesisError > > ( ) ?
. into_iter ( )
. flatten ( )
. collect ( ) ;
let computed_x : Vec < FpVar < CFG ::F > > = [
vec ! [ r_fp ] ,
points_aux ,
p_folded . to_constraint_field ( ) ? [ . . 2 ] . to_vec ( ) ,
]
. concat ( ) ;
computed_x . enforce_equal ( & x ) ? ;
Ok ( ( ) )
@ -596,13 +584,13 @@ pub mod tests {
use crate ::transcript ::poseidon ::poseidon_canonical_config ;
use crate ::utils ::get_cm_coordinates ;
struct TestCycleFoldConfig < C : CurveGroup > {
struct TestCycleFoldConfig < C : CurveGroup , const N : usize > {
_c : PhantomData < C > ,
}
impl < C : CurveGroup > CycleFoldConfig for TestCycleFoldConfig < C > {
impl < C : CurveGroup , const N : usize > CycleFoldConfig for TestCycleFoldConfig < C , N > {
const RANDOMNESS_BIT_LENGTH : usize = NOVA_N_BITS_RO ;
const N_INPUT_POINTS : usize = 2 ;
const N_INPUT_POINTS : usize = N ;
type C = C ;
type F = C ::BaseField ;
}
@ -630,46 +618,45 @@ pub mod tests {
}
#[ test ]
fn test_CycleFoldCircuit_constraints ( ) {
let ( _ , _ , _ , _ , ci1 , _ , ci2 , _ , ci3 , _ , cmT , r_bits , _ ) = prepare_simple_fold_inputs ( ) ;
let r_Fq = Fq ::from_bigint ( BigInteger ::from_bits_le ( & r_bits ) ) . unwrap ( ) ;
fn test_CycleFoldCircuit_n_points_constraints ( ) {
const n : usize = 16 ;
let mut rng = ark_std ::test_rng ( ) ;
// points to random-linear-combine
let points : Vec < Projective > = std ::iter ::repeat_with ( | | Projective ::rand ( & mut rng ) )
. take ( n )
. collect ( ) ;
use std ::ops ::Mul ;
let rho_raw = Fq ::rand ( & mut rng ) ;
let rho_bits = rho_raw . into_bigint ( ) . to_bits_le ( ) [ . . NOVA_N_BITS_RO ] . to_vec ( ) ;
let rho_Fq = Fq ::from_bigint ( BigInteger ::from_bits_le ( & rho_bits ) ) . unwrap ( ) ;
let rho_Fr = Fr ::from_bigint ( BigInteger ::from_bits_le ( & rho_bits ) ) . unwrap ( ) ;
let mut res = Projective ::zero ( ) ;
use ark_std ::One ;
let mut rho_i = Fr ::one ( ) ;
for point_i in points . iter ( ) {
res + = point_i . mul ( rho_i ) ;
rho_i * = rho_Fr ;
}
// cs is the Constraint System on the Curve Cycle auxiliary curve constraints field
// (E1::Fq=E2::Fr)
let cs = ConstraintSystem ::< Fq > ::new_ref ( ) ;
let cfW_u_i_x : Vec < Fq > = [
vec ! [ r_Fq ] ,
get_cm_coordinates ( & ci1 . cmW ) ,
get_cm_coordinates ( & ci2 . cmW ) ,
get_cm_coordinates ( & ci3 . cmW ) ,
]
. concat ( ) ;
let cfW_circuit = CycleFoldCircuit ::< TestCycleFoldConfig < Projective > , GVar > {
_gc : PhantomData ,
r_bits : Some ( vec ! [ r_bits . clone ( ) ] ) ,
points : Some ( vec ! [ ci1 . clone ( ) . cmW , ci2 . clone ( ) . cmW ] ) ,
x : Some ( cfW_u_i_x . clone ( ) ) ,
} ;
cfW_circuit . generate_constraints ( cs . clone ( ) ) . unwrap ( ) ;
assert ! ( cs . is_satisfied ( ) . unwrap ( ) ) ;
// same for E:
let cs = ConstraintSystem ::< Fq > ::new_ref ( ) ;
let cfE_u_i_x = [
vec ! [ r_Fq ] ,
get_cm_coordinates ( & ci1 . cmE ) ,
get_cm_coordinates ( & cmT ) ,
get_cm_coordinates ( & ci3 . cmE ) ,
let x : Vec < Fq > = [
vec ! [ rho_Fq ] ,
points . iter ( ) . flat_map ( get_cm_coordinates ) . collect ( ) ,
get_cm_coordinates ( & res ) ,
]
. concat ( ) ;
let cfE _circuit = CycleFoldCircuit ::< TestCycleFoldConfig < Projective > , GVar > {
let cf_circuit = CycleFoldCircuit ::< TestCycleFoldConfig < Projective , n > , GVar > {
_gc : PhantomData ,
r_bits : Some ( vec ! [ r_bits . clone ( ) ] ) ,
points : Some ( vec ! [ ci1 . clone ( ) . cmE , cmT ] ) ,
x : Some ( cfE_u_i_ x. clone ( ) ) ,
r_bits : Some ( rho_bits ) ,
points : Some ( points ) ,
x : Some ( x . clone ( ) ) ,
} ;
cfE _circuit . generate_constraints ( cs . clone ( ) ) . unwrap ( ) ;
cf_circuit . generate_constraints ( cs . clone ( ) ) . unwrap ( ) ;
assert ! ( cs . is_satisfied ( ) . unwrap ( ) ) ;
}
@ -714,7 +701,7 @@ pub mod tests {
u : Fr ::zero ( ) ,
cmW : Projective ::rand ( & mut rng ) ,
x : std ::iter ::repeat_with ( | | Fr ::rand ( & mut rng ) )
. take ( TestCycleFoldConfig ::< Projective > ::IO_LEN )
. take ( TestCycleFoldConfig ::< Projective , 2 > ::IO_LEN )
. collect ( ) ,
} ;
let U_i = CycleFoldCommittedInstance ::< Projective > {
@ -722,7 +709,7 @@ pub mod tests {
u : Fr ::rand ( & mut rng ) ,
cmW : Projective ::rand ( & mut rng ) ,
x : std ::iter ::repeat_with ( | | Fr ::rand ( & mut rng ) )
. take ( TestCycleFoldConfig ::< Projective > ::IO_LEN )
. take ( TestCycleFoldConfig ::< Projective , 2 > ::IO_LEN )
. collect ( ) ,
} ;
let cmT = Projective ::rand ( & mut rng ) ;
@ -781,7 +768,7 @@ pub mod tests {
u : Fr ::rand ( & mut rng ) ,
cmW : Projective ::rand ( & mut rng ) ,
x : std ::iter ::repeat_with ( | | Fr ::rand ( & mut rng ) )
. take ( TestCycleFoldConfig ::< Projective > ::IO_LEN )
. take ( TestCycleFoldConfig ::< Projective , 2 > ::IO_LEN )
. collect ( ) ,
} ;
let pp_hash = Fq ::from ( 42 u32 ) ; // only for test