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 | |
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ECFieldF2m(m: Int) Creates an elliptic curve characteristic 2 finite field which has 2^ |
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ECFieldF2m(m: Int, rp: BigInteger!) Creates an elliptic curve characteristic 2 finite field which has 2^ |
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ECFieldF2m(m: Int, ks: IntArray!) Creates an elliptic curve characteristic 2 finite field which has 2^ |
Public methods | |
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open Boolean |
Compares this finite field for equality with the specified object. |
open Int |
Returns the field size in bits which is |
open Int |
getM() Returns the value |
open 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. |
open 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. |
open Int |
hashCode() Returns a hash code value for this characteristic 2 finite field. |
Public constructors
ECFieldF2m
ECFieldF2m(m: Int)
Creates an elliptic curve characteristic 2 finite field which has 2^m
elements with normal basis.
Parameters | |
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m |
Int: with 2^m being the number of elements. |
Exceptions | |
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java.lang.IllegalArgumentException |
if m is not positive. |
ECFieldF2m
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 | |
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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 | |
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java.lang.NullPointerException |
if rp is null. |
java.lang.IllegalArgumentException |
if m is not positive, or rp does not represent a valid reduction polynomial. |
ECFieldF2m
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 | |
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java.lang.NullPointerException |
if ks is null. |
java.lang.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. |
Public methods
equals
open fun equals(other: Any?): Boolean
Compares this finite field for equality with the specified object.
Parameters | |
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obj |
the object to be compared. |
Return | |
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Boolean |
true if obj is an instance of ECFieldF2m and both m and the reduction polynomial match, false otherwise. |
getFieldSize
open fun getFieldSize(): Int
Returns the field size in bits which is m
for this characteristic 2 finite field.
Return | |
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Int |
the field size in bits. |
getM
open fun getM(): Int
Returns the value m
of this characteristic 2 finite field.
Return | |
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Int |
m with 2^m being the number of elements. |
getMidTermsOfReductionPolynomial
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 | |
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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
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 | |
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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
open fun hashCode(): Int
Returns a hash code value for this characteristic 2 finite field.
Return | |
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Int |
a hash code value. |