OpenJDK 1.23 · java.security.spec.ECFieldF2m · APIdia, the JavaDoc alternative

Modifier and Type	Field and Description
private final int[]	ks
private final int	m
private BigInteger	rp

Constructor Summary

Access	Constructor and Description
public	ECFieldF2m(int with 2^`m` being the number of elements. m) Creates an elliptic curve characteristic 2 finite field which has 2^`m` elements with normal basis.
public	ECFieldF2m(int with 2^`m` being the number of elements. m, BigInteger the BigInteger whose i-th bit corresponds to the i-th coefficient of the reduction polynomial. rp) Creates an elliptic curve characteristic 2 finite field which has 2^`m` elements with polynomial basis.
public	ECFieldF2m(int with 2^`m` being the number of elements. m, int[] the order of the middle term(s) of the reduction polynomial. Contents of this array are copied to protect against subsequent modification. ks) Creates an elliptic curve characteristic 2 finite field which has 2^`m` elements with polynomial basis.

Method Summary

Modifier and Type	Method and Description
public boolean	Returns: true if `obj` is an instance of ECFieldF2m and both `m` and the reduction polynomial match, false otherwise. equals(Object the object to be compared. obj) Overrides java.lang.Object.equals. Compares this finite field for equality with the specified object.
public int	Returns: the field size in bits. getFieldSize() Implements java.security.spec.ECField.getFieldSize. Returns the field size in bits which is `m` for this characteristic 2 finite field.
public int	Returns: `m` with 2^`m` being the number of elements. getM() Returns the value `m` of this characteristic 2 finite field.
public int[]	Returns: an integer array which contains the order of the middle term(s) of the reduction polynomial for polynomial basis or null for normal basis. A new array is returned each time this method is called. getMidTermsOfReductionPolynomial() Returns an integer array which contains the order of the middle term(s) of the reduction polynomial for polynomial basis or null for normal basis.
public BigInteger	Returns: a BigInteger whose i-th bit corresponds to the i-th coefficient of the reduction polynomial for polynomial basis or null for normal basis. getReductionPolynomial() Returns a BigInteger whose i-th bit corresponds to the i-th coefficient of the reduction polynomial for polynomial basis or null for normal basis.
public int	Returns: the hash code value for this characteristic 2 finite field hashCode() Overrides java.lang.Object.hashCode. Returns the hash code value for this characteristic 2 finite field.

Inherited from java.lang.Object:: clone finalize getClass notify notifyAll toString wait wait wait

Field Detail

ks	back to summary
private final int[] ks

m	back to summary
private final int m

rp	back to summary
private BigInteger rp

Constructor Detail

ECFieldF2m back to summary

ECFieldF2m	back to summary
public ECFieldF2m(int m) Creates an elliptic curve characteristic 2 finite field which has 2^`m` elements with normal basis. Parameters m:int with 2^`m` being the number of elements. Exceptions IllegalArgumentException: if `m` is not positive.

public ECFieldF2m(int m)

Creates an elliptic curve characteristic 2 finite field which has 2^m elements with normal basis.

Parameters

m:int: with 2^m being the number of elements.

Exceptions

IllegalArgumentException:: if m is not positive.

ECFieldF2m back to summary

ECFieldF2m	back to summary
public ECFieldF2m(int m, BigInteger rp) Creates an elliptic curve characteristic 2 finite field which has 2^`m` elements with polynomial basis. The reduction polynomial for this field is based on `rp` whose i-th bit corresponds to the i-th coefficient of the reduction polynomial. Note A valid reduction polynomial is either a trinomial (X^`m` + X^`k` + 1 with `m` > `k` >= 1) or a pentanomial (X^`m` + X^`k3` + X^`k2` + X^`k1` + 1 with `m` > `k3` > `k2` > `k1` >= 1). Parameters m:int with 2^`m` being the number of elements. rp:BigInteger the BigInteger whose i-th bit corresponds to the i-th coefficient of the reduction polynomial. Exceptions NullPointerException: if `rp` is null. IllegalArgumentException: if `m` is not positive, or `rp` does not represent a valid reduction polynomial.

public ECFieldF2m(int m, BigInteger rp)

Creates an elliptic curve characteristic 2 finite field which has 2^m elements with polynomial basis. The reduction polynomial for this field is based on rp whose i-th bit corresponds to the i-th coefficient of the reduction polynomial.

Note

A valid reduction polynomial is either a trinomial (X^m + X^k + 1 with m > k >= 1) or a pentanomial (X^m + X^k3 + X^k2 + X^k1 + 1 with m > k3 > k2 > k1 >= 1).

Parameters

m:int: with 2^m being the number of elements.
rp:BigInteger: the BigInteger whose i-th bit corresponds to the i-th coefficient of the reduction polynomial.

Exceptions

NullPointerException:: if rp is null.
IllegalArgumentException:: if m is not positive, or rp does not represent a valid reduction polynomial.

ECFieldF2m back to summary

ECFieldF2m	back to summary
public ECFieldF2m(int m, int[] ks) Creates an elliptic curve characteristic 2 finite field which has 2^`m` elements with polynomial basis. The reduction polynomial for this field is based on `ks` whose content contains the order of the middle term(s) of the reduction polynomial. Note A valid reduction polynomial is either a trinomial (X^`m` + X^`k` + 1 with `m` > `k` >= 1) or a pentanomial (X^`m` + X^`k3` + X^`k2` + X^`k1` + 1 with `m` > `k3` > `k2` > `k1` >= 1), so `ks` should have length 1 or 3. Parameters m:int with 2^`m` being the number of elements. ks:int[] the order of the middle term(s) of the reduction polynomial. Contents of this array are copied to protect against subsequent modification. Exceptions NullPointerException: if `ks` is null. IllegalArgumentException: if`m` is not positive, or the length of `ks` is neither 1 nor 3, or values in `ks` are not between `m`-1 and 1 (inclusive) and in descending order.

public ECFieldF2m(int m, int[] ks)

Creates an elliptic curve characteristic 2 finite field which has 2^m elements with polynomial basis. The reduction polynomial for this field is based on ks whose content contains the order of the middle term(s) of the reduction polynomial.

Note

A valid reduction polynomial is either a trinomial (X^m + X^k + 1 with m > k >= 1) or a pentanomial (X^m + X^k3 + X^k2 + X^k1 + 1 with m > k3 > k2 > k1 >= 1), so ks should have length 1 or 3.

Parameters

m:int: with 2^m being the number of elements.
ks:int[]: the order of the middle term(s) of the reduction polynomial. Contents of this array are copied to protect against subsequent modification.

Exceptions

NullPointerException:: if ks is null.
IllegalArgumentException:: ifm is not positive, or the length of ks is neither 1 nor 3, or values in ks are not between m-1 and 1 (inclusive) and in descending order.

Method Detail

equals back to summary

equals	back to summary
public boolean equals(Object obj) Overrides java.lang.Object.equals. Compares this finite field for equality with the specified object. Parameters obj:Object the object to be compared. Returns:boolean true if `obj` is an instance of ECFieldF2m and both `m` and the reduction polynomial match, false otherwise. Annotations @Override

public boolean equals(Object obj)

Overrides java.lang.Object.equals.

Compares this finite field for equality with the specified object.

Parameters

obj:Object: the object to be compared.

Returns:boolean

true if obj is an instance of ECFieldF2m and both m and the reduction polynomial match, false otherwise.

Annotations

@Override

getFieldSize back to summary

getFieldSize	back to summary
public int getFieldSize() Implements java.security.spec.ECField.getFieldSize. Returns the field size in bits which is `m` for this characteristic 2 finite field. Returns:int the field size in bits.

public int getFieldSize()

Implements java.security.spec.ECField.getFieldSize.

Returns the field size in bits which is m for this characteristic 2 finite field.

Returns:int: the field size in bits.

getM back to summary

getM	back to summary
public int getM() Returns the value `m` of this characteristic 2 finite field. Returns:int `m` with 2^`m` being the number of elements.

public int getM()

Returns the value m of this characteristic 2 finite field.

Returns:int: m with 2^m being the number of elements.

getMidTermsOfReductionPolynomial	back to summary
public int[] getMidTermsOfReductionPolynomial() Returns an integer array which contains the order of the middle term(s) of the reduction polynomial for polynomial basis or null for normal basis. Returns:int[] an integer array which contains the order of the middle term(s) of the reduction polynomial for polynomial basis or null for normal basis. A new array is returned each time this method is called.

getMidTermsOfReductionPolynomial

back to summary

public int[] getMidTermsOfReductionPolynomial()

Returns an integer array which contains the order of the middle term(s) of the reduction polynomial for polynomial basis or null for normal basis.

Returns:int[]: an integer array which contains the order of the middle term(s) of the reduction polynomial for polynomial basis or null for normal basis. A new array is returned each time this method is called.

getReductionPolynomial	back to summary
public BigInteger getReductionPolynomial() Returns a BigInteger whose i-th bit corresponds to the i-th coefficient of the reduction polynomial for polynomial basis or null for normal basis. Returns:BigInteger a BigInteger whose i-th bit corresponds to the i-th coefficient of the reduction polynomial for polynomial basis or null for normal basis.

getReductionPolynomial

back to summary

public BigInteger getReductionPolynomial()

Returns a BigInteger whose i-th bit corresponds to the i-th coefficient of the reduction polynomial for polynomial basis or null for normal basis.

Returns:BigInteger: a BigInteger whose i-th bit corresponds to the i-th coefficient of the reduction polynomial for polynomial basis or null for normal basis.

hashCode	back to summary
public int hashCode() Overrides java.lang.Object.hashCode. Returns the hash code value for this characteristic 2 finite field. Returns:int the hash code value for this characteristic 2 finite field Annotations @Override

hashCode

back to summary

public int hashCode()

Overrides java.lang.Object.hashCode.

Returns the hash code value for this characteristic 2 finite field.

Returns:int

the hash code value for this characteristic 2 finite field

Annotations

@Override

public Class ECFieldF2m

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