net.i2p.crypto.eddsa.math.bigint

Class BigIntegerFieldElement

java.lang.Object

net.i2p.crypto.eddsa.math.FieldElement

net.i2p.crypto.eddsa.math.bigint.BigIntegerFieldElement

All Implemented Interfaces:

Serializable

public class BigIntegerFieldElement
extends FieldElement
implements Serializable

A particular element of the field \Z/(2^255-19).

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
(package private) BigInteger	bi Variable is package private for encoding.

Fields inherited from class net.i2p.crypto.eddsa.math.FieldElement

f

Constructor Summary

Constructors

Constructor and Description
BigIntegerFieldElement(Field f, BigInteger bi)

Method Summary

Modifier and Type	Method and Description
FieldElement	add(FieldElement val) Adds another field element to this one.
FieldElement	addOne() Adds one to this field element.
FieldElement	cmov(FieldElement val, int b) Conditional move - sets this element to val if b is 1, otherwise leaves it unchanged.
FieldElement	divide(BigInteger val)
FieldElement	divide(FieldElement val) Divides this field element by another one.
boolean	equals(Object obj)
int	hashCode()
FieldElement	invert() Computes the multiplicative inverse of this field element.
boolean	isNonZero() Checks if this field element is non-zero.
FieldElement	mod(FieldElement m)
FieldElement	modPow(FieldElement e, FieldElement m)
FieldElement	multiply(FieldElement val) Multiplies this field element by another one.
FieldElement	negate() Negates this field element.
FieldElement	pow(FieldElement e)
FieldElement	pow22523() Raises this field element to the power of $2^{252} - 3$.
FieldElement	square() Squares this field element.
FieldElement	squareAndDouble() Squares this field element and doubles the result.
FieldElement	subtract(FieldElement val) Subtracts another field element from this one.
FieldElement	subtractOne() Subtracts one from this field element.
String	toString()

Methods inherited from class net.i2p.crypto.eddsa.math.FieldElement

isNegative, toByteArray

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

bi

final BigInteger bi

Variable is package private for encoding.

Constructor Detail

BigIntegerFieldElement

public BigIntegerFieldElement(Field f,
                              BigInteger bi)

Method Detail

add

public FieldElement add(FieldElement val)

Description copied from class: FieldElement

Adds another field element to this one.

Specified by:

add in class FieldElement

Parameters:

val - the field element to add

Returns:

the sum of this element and val

addOne

public FieldElement addOne()

Description copied from class: FieldElement

Adds one to this field element.

Overrides:

addOne in class FieldElement

Returns:

this element plus one

cmov

public FieldElement cmov(FieldElement val,
                         int b)

Description copied from class: FieldElement

Conditional move - sets this element to val if b is 1, otherwise leaves it unchanged.

Specified by:

cmov in class FieldElement

Parameters:

val - the field element to potentially assign

b - the condition: 1 means assign val, 0 means keep this element

Returns:

this element, potentially modified

divide

public FieldElement divide(BigInteger val)

divide

public FieldElement divide(FieldElement val)

Description copied from class: FieldElement

Divides this field element by another one.

Overrides:

divide in class FieldElement

Parameters:

val - the divisor

Returns:

this element divided by val

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

invert

public FieldElement invert()

Description copied from class: FieldElement

Computes the multiplicative inverse of this field element.

Specified by:

invert in class FieldElement

Returns:

the multiplicative inverse of this element

isNonZero

public boolean isNonZero()

Description copied from class: FieldElement

Checks if this field element is non-zero.

Specified by:

isNonZero in class FieldElement

Returns:

true if this element is not equal to zero, false otherwise

mod

public FieldElement mod(FieldElement m)

modPow

public FieldElement modPow(FieldElement e,
                           FieldElement m)

multiply

public FieldElement multiply(FieldElement val)

Description copied from class: FieldElement

Multiplies this field element by another one.

Specified by:

multiply in class FieldElement

Parameters:

val - the multiplier

Returns:

the product of this element and val

negate

public FieldElement negate()

Description copied from class: FieldElement

Negates this field element.

Specified by:

negate in class FieldElement

Returns:

the negation of this element

pow

public FieldElement pow(FieldElement e)

pow22523

public FieldElement pow22523()

Description copied from class: FieldElement

Raises this field element to the power of $2^{252} - 3$.

Specified by:

pow22523 in class FieldElement

Returns:

this element raised to the power of $2^{252} - 3$

square

public FieldElement square()

Description copied from class: FieldElement

Squares this field element.

Specified by:

square in class FieldElement

Returns:

this element squared

squareAndDouble

public FieldElement squareAndDouble()

Description copied from class: FieldElement

Squares this field element and doubles the result.

Specified by:

squareAndDouble in class FieldElement

Returns:

(this element squared) * 2

subtract

public FieldElement subtract(FieldElement val)

Description copied from class: FieldElement

Subtracts another field element from this one.

Specified by:

subtract in class FieldElement

Parameters:

val - the field element to subtract

Returns:

the difference of this element and val

subtractOne

public FieldElement subtractOne()

Description copied from class: FieldElement

Subtracts one from this field element.

Overrides:

subtractOne in class FieldElement

Returns:

this element minus one

toString

public String toString()

Overrides:

toString in class Object