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The ZK-SNARK library at the core of Aztec
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Public Types | Public Member Functions | Static Public Member Functions | Static Public Attributes | Private Attributes | List of all members
bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup > Class Template Reference

Custom element class for when using goblin. More...

#include <biggroup_goblin.hpp>

Public Types

using Builder = Builder_
 
using BaseField = Fq
 
using bool_ct = stdlib::bool_t< Builder >
 
using biggroup_tag = goblin_element
 

Public Member Functions

 goblin_element ()=default
 
 goblin_element (const typename NativeGroup::affine_element &input)
 
 goblin_element (const Fq &x, const Fq &y, bool assert_on_curve=true)
 
 goblin_element (const goblin_element &other)=default
 
 goblin_element (goblin_element &&other) noexcept=default
 
goblin_element & operator= (const goblin_element &other)=default
 
goblin_element & operator= (goblin_element &&other) noexcept=default
 
 ~goblin_element ()=default
 
void incomplete_assert_equal (const goblin_element &other, const std::string msg="goblin_element::incomplete_assert_equal") const
 Asserts that two goblin elements are equal (i.e., x, y coordinates are equal).
 
void convert_constant_to_fixed_witness (Builder *builder)
 Creates fixed witnesses from a constant element.
 
void fix_witness ()
 
void validate_on_curve () const
 
goblin_element checked_unconditional_add (const goblin_element &other) const
 
goblin_element checked_unconditional_subtract (const goblin_element &other) const
 
goblin_element operator+ (const goblin_element &other) const
 
goblin_element operator- (const goblin_element &other) const
 
goblin_element operator- () const
 
goblin_element operator+= (const goblin_element &other)
 
goblin_element operator-= (const goblin_element &other)
 
std::array< goblin_element, 2 > checked_unconditional_add_sub (const goblin_element &other) const
 
goblin_element operator* (const Fr &scalar) const
 
goblin_element conditional_negate (const bool_ct &predicate) const
 
goblin_element conditional_select (const goblin_element &other, const bool_ct &predicate) const
 Selects this if predicate is false, other if predicate is true.
 
goblin_element normalize () const
 
goblin_element reduce () const
 
goblin_element dbl () const
 
NativeGroup::affine_element get_value () const
 
Builder * get_context () const
 
Builder * get_context (const goblin_element &other) const
 
goblin_element get_standard_form () const
 
OriginTag get_origin_tag () const
 
void set_origin_tag (const OriginTag &tag) const
 
void set_free_witness_tag ()
 Set the free witness flag for the goblin element's tags.
 
void unset_free_witness_tag ()
 Unset the free witness flag for the goblin element's tags.
 
uint32_t set_public () const
 Set the witness indices representing the goblin element to public.
 
const Fq & x () const
 
const Fq & y () const
 
Fq & x ()
 
Fq & y ()
 

Static Public Member Functions

static goblin_element from_witness (Builder *ctx, const typename NativeGroup::affine_element &input)
 
static goblin_element one (Builder *ctx)
 
static goblin_element constant_infinity (Builder *ctx)
 Creates a constant point at infinity with canonical (0, 0) coordinates.
 
static goblin_element batch_mul (const std::vector< goblin_element > &points, const std::vector< Fr > &scalars, const size_t max_num_bits=0, const bool handle_edge_cases=false)
 Goblin style batch multiplication.
 

Static Public Attributes

static constexpr size_t PUBLIC_INPUTS_SIZE = BIGGROUP_PUBLIC_INPUTS_SIZE
 

Private Attributes

Fq _x
 
Fq _y
 

Detailed Description

template<class Builder_, class Fq, class Fr, class NativeGroup>
class bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >

Custom element class for when using goblin.

When using goblin (builder = MEGA and element = bn254), the assumptions and heuristics we apply vary considerably to the "default" case, justifying a separate class (we use a using declaration to make element map to goblin_element if the correct parametrisation is used, see the IsGoblinBigGroup concept for details) Differences between goblin and regular biggroup elements:

  1. state model is different (x/y coordinates are 2 136-bit field_t members instead of 4 68-bit field_t members)
  2. on-curve checks are not applied in-circuit (they are applied in the ECCVM circuit)
  3. we do not need to range-constrain the coordinates to be 136-bits (applied in the Translator circuit)
    Template Parameters
    Builder
    Fq
    Fr
    NativeGroup

Definition at line 31 of file biggroup_goblin.hpp.

Member Typedef Documentation

◆ BaseField

template<class Builder_ , class Fq , class Fr , class NativeGroup >
using bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::BaseField = Fq

Definition at line 34 of file biggroup_goblin.hpp.

◆ biggroup_tag

template<class Builder_ , class Fq , class Fr , class NativeGroup >
using bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::biggroup_tag = goblin_element

Definition at line 36 of file biggroup_goblin.hpp.

◆ bool_ct

template<class Builder_ , class Fq , class Fr , class NativeGroup >
using bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::bool_ct = stdlib::bool_t<Builder>

Definition at line 35 of file biggroup_goblin.hpp.

◆ Builder

template<class Builder_ , class Fq , class Fr , class NativeGroup >
using bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::Builder = Builder_

Definition at line 33 of file biggroup_goblin.hpp.

Constructor & Destructor Documentation

◆ goblin_element() [1/5]

template<class Builder_ , class Fq , class Fr , class NativeGroup >
bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::goblin_element ( )
default

◆ goblin_element() [2/5]

template<class Builder_ , class Fq , class Fr , class NativeGroup >
bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::goblin_element ( const typename NativeGroup::affine_element &  input)
inline

Definition at line 42 of file biggroup_goblin.hpp.

◆ goblin_element() [3/5]

template<class Builder_ , class Fq , class Fr , class NativeGroup >
bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::goblin_element ( const Fq &  x,
const Fq &  y,
bool  assert_on_curve = true 
)
inline

Definition at line 56 of file biggroup_goblin.hpp.

◆ goblin_element() [4/5]

template<class Builder_ , class Fq , class Fr , class NativeGroup >
bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::goblin_element ( const goblin_element< Builder_, Fq, Fr, NativeGroup > &  other)
default

◆ goblin_element() [5/5]

template<class Builder_ , class Fq , class Fr , class NativeGroup >
bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::goblin_element ( goblin_element< Builder_, Fq, Fr, NativeGroup > &&  other)
defaultnoexcept

◆ ~goblin_element()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::~goblin_element ( )
default

Member Function Documentation

◆ batch_mul()

template<typename C , class Fq , class Fr , class G >
goblin_element< C, Fq, Fr, G > bb::stdlib::element_goblin::goblin_element< C, Fq, Fr, G >::batch_mul ( const std::vector< goblin_element< Builder_, Fq, Fr, NativeGroup > > &  points,
const std::vector< Fr > &  scalars,
const size_t  max_num_bits = 0,
const bool  handle_edge_cases = false 
)
static

Goblin style batch multiplication.

In goblin-style arithmetization, the operands (points/scalars) for each mul-accumulate operation are decomposed into smaller components and written to an operation queue via the builder. The components are also added as witness variables. This function adds constraints demonstrating the fidelity of the point/scalar decompositions given the indices of the components in the variables array. The actual mul-accumulate operations are performed natively (without constraints) under the hood, and the final result is obtained by queueing an equality operation via the builder. The components of the result are returned as indices into the variables array from which the resulting accumulator point is re-constructed.

Note
Because this is the only method for performing Goblin-style group operations (Issue #707), it is sometimes used in situations where one of the scalars is 1 (e.g. to perform P = P_0 + z*P_1). In this case, we perform a simple add accumulate instead of a mul-then_accumulate.
Template Parameters
CCircuitBuilder
FqBase field
FrScalar field
GNative group
Parameters
points
scalars
max_num_bits
Returns
element<C, Fq, Fr, G>

Definition at line 39 of file biggroup_goblin_impl.hpp.

◆ checked_unconditional_add()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
goblin_element bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::checked_unconditional_add ( const goblin_element< Builder_, Fq, Fr, NativeGroup > &  other) const
inline

Definition at line 147 of file biggroup_goblin.hpp.

◆ checked_unconditional_add_sub()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
std::array< goblin_element, 2 > bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::checked_unconditional_add_sub ( const goblin_element< Builder_, Fq, Fr, NativeGroup > &  other) const
inline

Definition at line 232 of file biggroup_goblin.hpp.

◆ checked_unconditional_subtract()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
goblin_element bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::checked_unconditional_subtract ( const goblin_element< Builder_, Fq, Fr, NativeGroup > &  other) const
inline

Definition at line 148 of file biggroup_goblin.hpp.

◆ conditional_negate()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
goblin_element bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::conditional_negate ( const bool_ct &  predicate) const
inline

Definition at line 239 of file biggroup_goblin.hpp.

◆ conditional_select()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
goblin_element bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::conditional_select ( const goblin_element< Builder_, Fq, Fr, NativeGroup > &  other,
const bool_ct &  predicate 
) const
inline

Selects this if predicate is false, other if predicate is true.

Parameters
other
predicate
Returns
goblin_element

Definition at line 254 of file biggroup_goblin.hpp.

◆ constant_infinity()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
static goblin_element bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::constant_infinity ( Builder *  ctx)
inlinestatic

Creates a constant point at infinity with canonical (0, 0) coordinates.

Note
For witness infinity points, use from_witness(ctx, affine_element::infinity()) instead.

Definition at line 140 of file biggroup_goblin.hpp.

◆ convert_constant_to_fixed_witness()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
void bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::convert_constant_to_fixed_witness ( Builder *  builder)
inline

Creates fixed witnesses from a constant element.

Definition at line 102 of file biggroup_goblin.hpp.

◆ dbl()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
goblin_element bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::dbl ( ) const
inline

Definition at line 274 of file biggroup_goblin.hpp.

◆ fix_witness()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
void bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::fix_witness ( )
inline

Fix a witness. The value of the witness is constrained with a selector

Definition at line 112 of file biggroup_goblin.hpp.

◆ from_witness()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
static goblin_element bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::from_witness ( Builder *  ctx,
const typename NativeGroup::affine_element &  input 
)
inlinestatic

Definition at line 83 of file biggroup_goblin.hpp.

◆ get_context() [1/2]

template<class Builder_ , class Fq , class Fr , class NativeGroup >
Builder * bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::get_context ( ) const
inline

Definition at line 301 of file biggroup_goblin.hpp.

◆ get_context() [2/2]

template<class Builder_ , class Fq , class Fr , class NativeGroup >
Builder * bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::get_context ( const goblin_element< Builder_, Fq, Fr, NativeGroup > &  other) const
inline

Definition at line 312 of file biggroup_goblin.hpp.

◆ get_origin_tag()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
OriginTag bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::get_origin_tag ( ) const
inline

Definition at line 332 of file biggroup_goblin.hpp.

◆ get_standard_form()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
goblin_element bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::get_standard_form ( ) const
inline

Definition at line 330 of file biggroup_goblin.hpp.

◆ get_value()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
NativeGroup::affine_element bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::get_value ( ) const
inline

Definition at line 289 of file biggroup_goblin.hpp.

◆ incomplete_assert_equal()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
void bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::incomplete_assert_equal ( const goblin_element< Builder_, Fq, Fr, NativeGroup > &  other,
const std::string  msg = "goblin_element< Builder_, Fq, Fr, NativeGroup >::incomplete_assert_equal" 
) const
inline

Asserts that two goblin elements are equal (i.e., x, y coordinates are equal).

Parameters
other
msg

ECCVM ensures that point-at-infinity is canonically represented as (0, 0), so comparing coordinates is sufficient.

Definition at line 76 of file biggroup_goblin.hpp.

◆ normalize()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
goblin_element bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::normalize ( ) const
inline

Definition at line 262 of file biggroup_goblin.hpp.

◆ one()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
static goblin_element bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::one ( Builder *  ctx)
inlinestatic

Definition at line 127 of file biggroup_goblin.hpp.

◆ operator*()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
goblin_element bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::operator* ( const Fr &  scalar) const
inline

Definition at line 237 of file biggroup_goblin.hpp.

◆ operator+()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
goblin_element bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::operator+ ( const goblin_element< Builder_, Fq, Fr, NativeGroup > &  other) const
inline

Definition at line 150 of file biggroup_goblin.hpp.

◆ operator+=()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
goblin_element bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::operator+= ( const goblin_element< Builder_, Fq, Fr, NativeGroup > &  other)
inline

Definition at line 222 of file biggroup_goblin.hpp.

◆ operator-() [1/2]

template<class Builder_ , class Fq , class Fr , class NativeGroup >
goblin_element bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::operator- ( ) const
inline

Definition at line 216 of file biggroup_goblin.hpp.

◆ operator-() [2/2]

template<class Builder_ , class Fq , class Fr , class NativeGroup >
goblin_element bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::operator- ( const goblin_element< Builder_, Fq, Fr, NativeGroup > &  other) const
inline

Definition at line 156 of file biggroup_goblin.hpp.

◆ operator-=()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
goblin_element bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::operator-= ( const goblin_element< Builder_, Fq, Fr, NativeGroup > &  other)
inline

Definition at line 227 of file biggroup_goblin.hpp.

◆ operator=() [1/2]

template<class Builder_ , class Fq , class Fr , class NativeGroup >
goblin_element & bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::operator= ( const goblin_element< Builder_, Fq, Fr, NativeGroup > &  other)
default

◆ operator=() [2/2]

template<class Builder_ , class Fq , class Fr , class NativeGroup >
goblin_element & bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::operator= ( goblin_element< Builder_, Fq, Fr, NativeGroup > &&  other)
defaultnoexcept

◆ reduce()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
goblin_element bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::reduce ( ) const
inline

Definition at line 268 of file biggroup_goblin.hpp.

◆ set_free_witness_tag()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
void bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::set_free_witness_tag ( )
inline

Set the free witness flag for the goblin element's tags.

Definition at line 343 of file biggroup_goblin.hpp.

◆ set_origin_tag()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
void bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::set_origin_tag ( const OriginTag &  tag) const
inline

Definition at line 334 of file biggroup_goblin.hpp.

◆ set_public()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
uint32_t bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::set_public ( ) const
inline

Set the witness indices representing the goblin element to public.

Each coordinate (x, y) is represented using 2 native field elements (lo, hi). Total: 4 field elements per goblin element.

Returns
uint32_t The index into the public inputs array at which the representation of the goblin element starts

Definition at line 364 of file biggroup_goblin.hpp.

◆ unset_free_witness_tag()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
void bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::unset_free_witness_tag ( )
inline

Unset the free witness flag for the goblin element's tags.

Definition at line 352 of file biggroup_goblin.hpp.

◆ validate_on_curve()

template<class Builder_ , class Fq , class Fr , class NativeGroup >
void bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::validate_on_curve ( ) const
inline

Definition at line 122 of file biggroup_goblin.hpp.

◆ x() [1/2]

template<class Builder_ , class Fq , class Fr , class NativeGroup >
Fq & bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::x ( )
inline

Definition at line 376 of file biggroup_goblin.hpp.

◆ x() [2/2]

template<class Builder_ , class Fq , class Fr , class NativeGroup >
const Fq & bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::x ( ) const
inline

Definition at line 373 of file biggroup_goblin.hpp.

◆ y() [1/2]

template<class Builder_ , class Fq , class Fr , class NativeGroup >
Fq & bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::y ( )
inline

Definition at line 377 of file biggroup_goblin.hpp.

◆ y() [2/2]

template<class Builder_ , class Fq , class Fr , class NativeGroup >
const Fq & bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::y ( ) const
inline

Definition at line 374 of file biggroup_goblin.hpp.

Member Data Documentation

◆ _x

template<class Builder_ , class Fq , class Fr , class NativeGroup >
Fq bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::_x
private

Definition at line 380 of file biggroup_goblin.hpp.

◆ _y

template<class Builder_ , class Fq , class Fr , class NativeGroup >
Fq bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::_y
private

Definition at line 381 of file biggroup_goblin.hpp.

◆ PUBLIC_INPUTS_SIZE

template<class Builder_ , class Fq , class Fr , class NativeGroup >
constexpr size_t bb::stdlib::element_goblin::goblin_element< Builder_, Fq, Fr, NativeGroup >::PUBLIC_INPUTS_SIZE = BIGGROUP_PUBLIC_INPUTS_SIZE
staticconstexpr

Definition at line 39 of file biggroup_goblin.hpp.

The documentation for this class was generated from the following files: