Public Member Functions | Protected Attributes | List of all members
arithm::Field Class Reference

Models a mathematical field with a given additive order, multiplicative order, addition, multiplication, unit and zero. More...

#include <field.hpp>

+ Inheritance diagram for arithm::Field:
+ Collaboration diagram for arithm::Field:

Public Member Functions

 Field (mpz_class aOrder)
 Constructs a Field instance by setting only the value of addOrder, generator and multOrder being set to 1 and 0.
 Field (mpz_class aOrder, mpz_class mOrder, mpz_class gen)
 Constructs a Field instance by setting the values of addOrder, multOrder and generator.
Additive element operations
virtual Elmt addition (Elmt e1, Elmt e2)
 Returns $e_1 + e_2$ as an element of this field.
virtual Elmt addInverse (Elmt e)
 Returns $-e$ as an element of the field.
Additive array operations
ArrayOfElmts addition (ArrayOfElmts e1, ArrayOfElmts e2)
 Returns $R ~|~ R_i = e_{1,i} + e_{2,i}$. If the sizes mismatch, exits with exitcode 1.
ArrayOfElmts addInverse (ArrayOfElmts a)
 Returns $R ~|~ R_i = (-1) \times a_i$ as an array of elements of this field.
Elmt sum (ArrayOfElmts a)
 Returns $s = \sum a_i$ as an element of this field.
Obtaining field elements
Elmt getZero ()
 Returns the neutral element for addition.
ArrayOfElmts getZero (unsigned int n)
 Returns an array of field elements containging n copies of the neutral element for addition.
Data about the field.
mpz_class getAddOrder ()
unsigned int getLeafSize ()
 Returns the byte size the leaves representing element of this group must have.
virtual std::string getType ()
 Returns a string containing the name of this Group.
- Public Member Functions inherited from arithm::Group
 Group (mpz_class order, mpz_class gen)
 Sets the attributes of a new group instance.
virtual verifierUtils::ByteTree * toByteTree ()
 Returns the bytetree representation of this group.
virtual Elmt multiplication (Elmt e1, Elmt e2)
 Returns the product of the two elements as an element of this group.
virtual Elmt multInverse (Elmt e)
 Returns $e^{-1}$ as an element of this group.
virtual Elmt exponentiation (Elmt e, Elmt s)
 Returns the $e^s$ as an element of this group.
bool compare (Elmt e1, Elmt e2)
 Returns true if e1 and e2 have identical values, false otherwise.
ArrayOfElmts multiplication (ArrayOfElmts e1, ArrayOfElmts e2)
 Returns $R ~|~ R_i = e_{1,i} \times e_{2,i}$ as an array of elements of this group.
ArrayOfElmts multInverse (ArrayOfElmts e)
 Returns $R ~|~ R_i = e_i^{-1}$ as an array of elements of this group.
ArrayOfElmts exponentiation (ArrayOfElmts e, ArrayOfElmts s)
 Returns $R ~|~ R_i = e_i^{s_i}$ as an array of elements of this group.
Elmt product (ArrayOfElmts e)
 Returns $r = \prod e_i$ as an element of this group.
Elmt expProduct (ArrayOfElmts e, ArrayOfElmts s)
 Returns $r = \prod e_i^{s_i}$ as an element of this group.
bool compare (ArrayOfElmts e1, ArrayOfElmts e2)
 Returns true if e1 and e2 have identical values component-wise, false if at least one of the component is different.
virtual Elmt encode (std::vector< uint8_t > message)
 Encodes the message into a element of this group.
virtual std::vector< uint8_t > decode (Elmt e)
 Returns the element encoded in the element given as a paramater.
Elmt getOne ()
 Returns an element containing the unit of this group.
ArrayOfElmts getOne (unsigned int n)
 Returns an array containing n copies of the unit of this group.
Elmt getElmt (mpz_class repr)
 Returns the element of this group which has repr as a representative.
Elmt getElmt (verifierUtils::ByteTree *bt)
 Returns the element of this group which bt as a bytetree representation.
ArrayOfElmts getArray (verifierUtils::ByteTree *bt)
 Returns the array of elements of this group which has bt as a bytetree representation.
virtual ArrayOfElmts getRandArray (cryptoTools::PRG *prg, unsigned int nr, unsigned int n0)
 Returns an array of elements of size n0 derived using a prg.
mpz_class getMultOrder ()
 Returns the multiplicative generator of this group.
Elmt getGenerator ()
 Returns the multiplicative generator of this group as an element of this group.
ArrayOfElmts getGenerator (unsigned int n)
 Returns an array containing n copies of the multiplicative order of this group.
virtual bool isIn (mpz_class repr)
 Returns true if the element of representative repr is in this group.

Protected Attributes

mpz_class addOrder
 The additive order (characteristic) of the field.
- Protected Attributes inherited from arithm::Group
mpz_class multOrder
 The order of this multiplicative group.
mpz_class generator
 The generator to use for this group.

Detailed Description

Models a mathematical field with a given additive order, multiplicative order, addition, multiplication, unit and zero.

It is a virtual class providing an interface that has to be implemented by every field used in verificatum.

Definition at line 32 of file field.hpp.

Constructor & Destructor Documentation

Field::Field ( mpz_class  aOrder)

Constructs a Field instance by setting only the value of addOrder, generator and multOrder being set to 1 and 0.

Definition at line 18 of file field.cpp.

: Group(1,0)
{
addOrder = aOrder;
}
Field::Field ( mpz_class  aOrder,
mpz_class  mOrder,
mpz_class  gen 
)

Constructs a Field instance by setting the values of addOrder, multOrder and generator.

Definition at line 24 of file field.cpp.

:
Group(mOrder,gen)
{
addOrder = aOrder;
}

Member Function Documentation

Elmt Field::addInverse ( Elmt  e)
virtual

Returns $-e$ as an element of the field.

Reimplemented in arithm::ModField.

Definition at line 42 of file field.cpp.

{
return Elmt(0,this);
}
ArrayOfElmts Field::addInverse ( ArrayOfElmts  a)

Returns $R ~|~ R_i = (-1) \times a_i$ as an array of elements of this field.

Definition at line 70 of file field.cpp.

{
ArrayOfElmts result;
for (unsigned int i=0; i<a.size(); i++)
result.addElmt(addInverse(a.getElmt(i)));
return result;
}
Elmt Field::addition ( Elmt  e1,
Elmt  e2 
)
virtual

Returns $e_1 + e_2$ as an element of this field.

Reimplemented in arithm::ModField.

Definition at line 36 of file field.cpp.

{
return Elmt(0,this);
}
ArrayOfElmts Field::addition ( ArrayOfElmts  e1,
ArrayOfElmts  e2 
)

Returns $R ~|~ R_i = e_{1,i} + e_{2,i}$. If the sizes mismatch, exits with exitcode 1.

Definition at line 53 of file field.cpp.

{
if (e1.size() != e2.size())
{
std::cout<<"ERROR: in Field.addition(e1,e2), sizes of "
<<"e1 and e2 mismatch."
<<"\ne1.size()"<<e1.size()
<<"\ne2.size()"<<e2.size()<<std::endl;
exit(1);
}
ArrayOfElmts result;
for (unsigned int i=0; i<e1.size(); i++)
result.addElmt(addition(e1.getElmt(i),e2.getElmt(i)));
return result;
}
mpz_class Field::getAddOrder ( )
Returns
The addOrder attribute.

Definition at line 113 of file field.cpp.

{
return addOrder;
}
unsigned int Field::getLeafSize ( )
virtual

Returns the byte size the leaves representing element of this group must have.

Reimplemented from arithm::Group.

Definition at line 119 of file field.cpp.

{
return ((unsigned int)mpz_sizeinbase(
addOrder.get_mpz_t(), 16)+1)/2;
}
std::string Field::getType ( )
virtual

Returns a string containing the name of this Group.

Reimplemented from arithm::Group.

Reimplemented in arithm::ModField.

Definition at line 126 of file field.cpp.

{
return "Field";
}
Elmt Field::getZero ( )

Returns the neutral element for addition.

Definition at line 93 of file field.cpp.

{
return Elmt(0,this);
}
ArrayOfElmts Field::getZero ( unsigned int  n)

Returns an array of field elements containging n copies of the neutral element for addition.

Definition at line 99 of file field.cpp.

{
ArrayOfElmts result;
for (unsigned int i=0; i<n; i++)
result.addElmt(getZero());
return result;
}
Elmt Field::sum ( ArrayOfElmts  a)

Returns $s = \sum a_i$ as an element of this field.

Definition at line 79 of file field.cpp.

{
Elmt result = getZero();
for (unsigned int i=0; i<a.size(); i++)
result = addition(result, a.getElmt(i));
return result;
}

Member Data Documentation

mpz_class arithm::Field::addOrder
protected

The additive order (characteristic) of the field.

Definition at line 38 of file field.hpp.

The documentation for this class was generated from the following files:
Generated on Sun Sep 30 2012 15:28:22 for VerificatumVerifier by doxygen 1.8.1.2