Added in API level 1

ECFieldF2m

open class ECFieldF2m : ECField

kotlin.Any
↳	java.security.spec.ECFieldF2m

This immutable class defines an elliptic curve (EC) characteristic 2 finite field.

Summary

Public constructors
`ECFieldF2m(m: Int)` Creates an elliptic curve characteristic 2 finite field which has 2^`m` elements with normal basis.
`ECFieldF2m(m: Int, ks: IntArray!)` Creates an elliptic curve characteristic 2 finite field which has 2^`m` elements with polynomial basis.
`ECFieldF2m(m: Int, rp: BigInteger!)` Creates an elliptic curve characteristic 2 finite field which has 2^`m` elements with polynomial basis.

Public methods
open Boolean	`equals(other: Any?)` Compares this finite field for equality with the specified object.
open Int	`getFieldSize()` Returns the field size in bits which is `m` for this characteristic 2 finite field.
open Int	`getM()` Returns the value `m` of this characteristic 2 finite field.
open IntArray!	`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.
open 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.
open Int	`hashCode()` Returns a hash code value for this characteristic 2 finite field.

Public constructors

ECFieldF2m

Added in API level 1

ECFieldF2m(m: Int)

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
`java.lang.IllegalArgumentException`	if `m` is not positive.

ECFieldF2m

Added in API level 1

ECFieldF2m(
    m: Int, 
    ks: IntArray!)

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`	IntArray!: the order of the middle term(s) of the reduction polynomial. Contents of this array are copied to protect against subsequent modification.

Exceptions
`java.lang.NullPointerException`	if `ks` is null.
`java.lang.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.

ECFieldF2m

Added in API level 1

ECFieldF2m(
    m: Int, 
    rp: BigInteger!)

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

Public methods

equals

Added in API level 1

open fun equals(other: Any?): Boolean

Compares this finite field for equality with the specified object.

Parameters
`obj`	the object to be compared.

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

getFieldSize

Added in API level 1

open fun getFieldSize(): Int

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

Return
`Int`	the field size in bits.

getM

Added in API level 1

open fun getM(): Int

Returns the value m of this characteristic 2 finite field.

Return
`Int`	`m` with 2^`m` being the number of elements.

getMidTermsOfReductionPolynomial

Added in API level 1

open fun getMidTermsOfReductionPolynomial(): IntArray!

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.

Return
`IntArray!`	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

Added in API level 1

open fun getReductionPolynomial(): 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.

Return
`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

Added in API level 1

open fun hashCode(): Int

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

Return
`Int`	a hash code value.