iaik.security.ec.math.field

Interface FieldElement

All Superinterfaces:

Cloneable, GenericFieldElement

All Known Implementing Classes:

BinaryFieldElement, PrimeFieldElement

public interface FieldElement
extends GenericFieldElement

This interface represents elements of finite fields and provides the most important arithmetical methods.

Author:

Christian Hanser, Sebastian Ramacher

See Also:

Field, BinaryFieldElement, PrimeFieldElement

Method Summary

Modifier and Type	Method and Description
FieldElement	add(GenericFieldElement b) Adds b to this.
FieldElement	addBase(GenericFieldElement B) Adds b to this where b is an element of the underlying base field.
FieldElement	clone() Clones the value of this field element.
FieldElement	divide(GenericFieldElement b) Divides this and another field elements.
FieldElement	exponentiate(BigInteger n) Raises this to the power n.
int	getBit(int index) Returns the value of a certain bit of this.
FieldElement	invert() Sets this to its inverse.
FieldElement	multiply(BigInteger n) Multiples this by n.
FieldElement	multiply(GenericFieldElement b) Multiplies this with b which is an element of the same field.
FieldElement	multiplyByBase(GenericFieldElement b) Multiplies this with b which is an element of the base field.
FieldElement	multiplyByBaseOutOfPlace(GenericFieldElement b) Multiplies this with b which is an element of the base field, where a new object holding the result is created.
FieldElement	multiplyOutOfPlace(BigInteger n) Multiples this by n, where a new object holding the result is created.
FieldElement	multiplyOutOfPlace(GenericFieldElement b) Multiplies this with b which is an element of the same field, where a new object holding the result is created.
FieldElement	negate() Returns the negative of this.
FieldElement	square() Computes the square of this in-place.
FieldElement	squareOutOfPlace() Computes the square of this, where a new object holding the result is created.
FieldElement	squareRoot() Computes the square root of this.
FieldElement	subtract(GenericFieldElement b) Subtracts b from this.
boolean	testBit(int index) Tests whether a certain bit of this is set.
BigInteger	toBigInteger() Returns the BigInteger-representation of this instance.

Methods inherited from interface iaik.security.ec.math.field.GenericFieldElement

addOutOfPlace, equals, exponentiate, exponentiateByPowerOf2, exponentiateOutOfPlace, exponentiateOutOfPlace, getField, hashCode, isOne, isZero, negateOutOfPlace, subtractOutOfPlace, toByteArray, toString

Method Detail

negate

FieldElement negate()

Description copied from interface: GenericFieldElement

Returns the negative of this. This functions works in-place.

Specified by:

negate in interface GenericFieldElement

Returns:

the negative of this

add

FieldElement add(GenericFieldElement b)

Description copied from interface: GenericFieldElement

Adds b to this. This functions works in-place.

Specified by:

add in interface GenericFieldElement

Parameters:

b - the second addend

Returns:

the sum of this and b

addBase

FieldElement addBase(GenericFieldElement B)

Description copied from interface: GenericFieldElement

Adds b to this where b is an element of the underlying base field.

Specified by:

addBase in interface GenericFieldElement

Parameters:

B - the second addend

Returns:

the sum of this and b

subtract

FieldElement subtract(GenericFieldElement b)

Description copied from interface: GenericFieldElement

Subtracts b from this. This functions works in-place.

Specified by:

subtract in interface GenericFieldElement

Parameters:

b - the subtrahend

Returns:

the difference of this and b

invert

FieldElement invert()

Description copied from interface: GenericFieldElement

Sets this to its inverse.

Specified by:

invert in interface GenericFieldElement

Returns:

the inverse of this

multiply

FieldElement multiply(GenericFieldElement b)

Description copied from interface: GenericFieldElement

Multiplies this with b which is an element of the same field.

Specified by:

multiply in interface GenericFieldElement

Parameters:

b - the second factor

Returns:

the product of this and b

multiplyOutOfPlace

FieldElement multiplyOutOfPlace(GenericFieldElement b)

Description copied from interface: GenericFieldElement

Multiplies this with b which is an element of the same field, where a new object holding the result is created.

Specified by:

multiplyOutOfPlace in interface GenericFieldElement

Parameters:

b - the second factor

Returns:

the product of this and b

multiply

FieldElement multiply(BigInteger n)

Description copied from interface: GenericFieldElement

Multiples this by n.

Specified by:

multiply in interface GenericFieldElement

Parameters:

n - the factor

Returns:

the product of this and n

multiplyOutOfPlace

FieldElement multiplyOutOfPlace(BigInteger n)

Description copied from interface: GenericFieldElement

Multiples this by n, where a new object holding the result is created.

Specified by:

multiplyOutOfPlace in interface GenericFieldElement

Parameters:

n - the factor

Returns:

the product of this and n

multiplyByBase

FieldElement multiplyByBase(GenericFieldElement b)

Description copied from interface: GenericFieldElement

Multiplies this with b which is an element of the base field.

Specified by:

multiplyByBase in interface GenericFieldElement

Parameters:

b - the second factor

Returns:

the product of this and b

multiplyByBaseOutOfPlace

FieldElement multiplyByBaseOutOfPlace(GenericFieldElement b)

Description copied from interface: GenericFieldElement

Multiplies this with b which is an element of the base field, where a new object holding the result is created.

Specified by:

multiplyByBaseOutOfPlace in interface GenericFieldElement

Parameters:

b - the second factor

Returns:

the product of this and b

divide

FieldElement divide(GenericFieldElement b)

Description copied from interface: GenericFieldElement

Divides this and another field elements.

Specified by:

divide in interface GenericFieldElement

Parameters:

b - the divisor

Returns:

the quotient of this and b

square

FieldElement square()

Description copied from interface: GenericFieldElement

Computes the square of this in-place.

Specified by:

square in interface GenericFieldElement

Returns:

the square of this

squareOutOfPlace

FieldElement squareOutOfPlace()

Description copied from interface: GenericFieldElement

Computes the square of this, where a new object holding the result is created.

Specified by:

squareOutOfPlace in interface GenericFieldElement

Returns:

the square of this

exponentiate

FieldElement exponentiate(BigInteger n)

Description copied from interface: GenericFieldElement

Raises this to the power n. Works in-place.

Specified by:

exponentiate in interface GenericFieldElement

Parameters:

n - the exponent

Returns:

the nth power of this

squareRoot

FieldElement squareRoot()

Computes the square root of this.

Specified by:

squareRoot in interface GenericFieldElement

Returns:

a field element representing the square root of this

testBit

boolean testBit(int index)

Tests whether a certain bit of this is set.

Parameters:

index - the index of the bit

Returns:

true if the bit is 1; false otherwise

getBit

int getBit(int index)

Returns the value of a certain bit of this.

Parameters:

index - the index of the bit

Returns:

the value of a certain bit, i.e. 0 or 1

toBigInteger

BigInteger toBigInteger()

Returns the BigInteger-representation of this instance.

Returns:

the BigInteger-representation

clone

FieldElement clone()

Clones the value of this field element.

Specified by:

clone in interface GenericFieldElement

Returns:

the clone