# ECParameterSpec

Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)  
Summary:[Ctors](https://developer.android.com/reference/java/security/spec/ECParameterSpec#pubctors)\|[Methods](https://developer.android.com/reference/java/security/spec/ECParameterSpec#pubmethods)\|[Inherited Methods](https://developer.android.com/reference/java/security/spec/ECParameterSpec#inhmethods)  

# ECParameterSpec

`
public


class
ECParameterSpec
`  
`

extends `[Object](https://developer.android.com/reference/java/lang/Object)`


``


implements

`[AlgorithmParameterSpec](https://developer.android.com/reference/java/security/spec/AlgorithmParameterSpec)`


`

|---|------------------------------------|
| [java.lang.Object](https://developer.android.com/reference/java/lang/Object) ||
| ↳ | java.security.spec.ECParameterSpec |

<br />

*** ** * ** ***

This immutable class specifies the set of domain parameters used with elliptic curve cryptography (ECC).  
**See also:**

- [AlgorithmParameterSpec](https://developer.android.com/reference/java/security/spec/AlgorithmParameterSpec)

## Summary

|                                                                                                                                                                                                                                                                          ### Public constructors                                                                                                                                                                                                                                                                           ||
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---|
| ` `[ECParameterSpec](https://developer.android.com/reference/java/security/spec/ECParameterSpec#ECParameterSpec(java.security.spec.EllipticCurve,%20java.security.spec.ECPoint,%20java.math.BigInteger,%20int))`(`[EllipticCurve](https://developer.android.com/reference/java/security/spec/EllipticCurve)` curve, `[ECPoint](https://developer.android.com/reference/java/security/spec/ECPoint)` g, `[BigInteger](https://developer.android.com/reference/java/math/BigInteger)` n, int h) ` Creates elliptic curve domain parameters based on the specified values. |

|                                                                                                                              ### Public methods                                                                                                                              ||
|----------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| ` int`                                                                                       | ` `[getCofactor](https://developer.android.com/reference/java/security/spec/ECParameterSpec#getCofactor())`() ` Returns the cofactor.                                          |
| ` `[EllipticCurve](https://developer.android.com/reference/java/security/spec/EllipticCurve) | ` `[getCurve](https://developer.android.com/reference/java/security/spec/ECParameterSpec#getCurve())`() ` Returns the elliptic curve that this parameter defines.              |
| ` `[ECPoint](https://developer.android.com/reference/java/security/spec/ECPoint)             | ` `[getGenerator](https://developer.android.com/reference/java/security/spec/ECParameterSpec#getGenerator())`() ` Returns the generator which is also known as the base point. |
| ` `[BigInteger](https://developer.android.com/reference/java/math/BigInteger)                | ` `[getOrder](https://developer.android.com/reference/java/security/spec/ECParameterSpec#getOrder())`() ` Returns the order of the generator.                                  |

| ### Inherited methods |
|-----------------------|---|
| From class` `[java.lang.Object](https://developer.android.com/reference/java/lang/Object)` ` |--------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | ` `[Object](https://developer.android.com/reference/java/lang/Object)          | ` `[clone](https://developer.android.com/reference/java/lang/Object#clone())`() ` Creates and returns a copy of this object.                                                                                                                                                      | | ` boolean`                                                                     | ` `[equals](https://developer.android.com/reference/java/lang/Object#equals(java.lang.Object))`(`[Object](https://developer.android.com/reference/java/lang/Object)` obj) ` Indicates whether some other object is "equal to" this one.                                           | | ` void`                                                                        | ` `[finalize](https://developer.android.com/reference/java/lang/Object#finalize())`() ` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.                                                          | | ` final `[Class](https://developer.android.com/reference/java/lang/Class)`<?>` | ` `[getClass](https://developer.android.com/reference/java/lang/Object#getClass())`() ` Returns the runtime class of this`Object`.                                                                                                                                                | | ` int`                                                                         | ` `[hashCode](https://developer.android.com/reference/java/lang/Object#hashCode())`() ` Returns a hash code value for the object.                                                                                                                                                 | | ` final void`                                                                  | ` `[notify](https://developer.android.com/reference/java/lang/Object#notify())`() ` Wakes up a single thread that is waiting on this object's monitor.                                                                                                                            | | ` final void`                                                                  | ` `[notifyAll](https://developer.android.com/reference/java/lang/Object#notifyAll())`() ` Wakes up all threads that are waiting on this object's monitor.                                                                                                                         | | ` `[String](https://developer.android.com/reference/java/lang/String)          | ` `[toString](https://developer.android.com/reference/java/lang/Object#toString())`() ` Returns a string representation of the object.                                                                                                                                            | | ` final void`                                                                  | ` `[wait](https://developer.android.com/reference/java/lang/Object#wait(long,%20int))`(long timeoutMillis, int nanos) ` Causes the current thread to wait until it is awakened, typically by being*notified* or*interrupted*, or until a certain amount of real time has elapsed. | | ` final void`                                                                  | ` `[wait](https://developer.android.com/reference/java/lang/Object#wait(long))`(long timeoutMillis) ` Causes the current thread to wait until it is awakened, typically by being*notified* or*interrupted*, or until a certain amount of real time has elapsed.                   | | ` final void`                                                                  | ` `[wait](https://developer.android.com/reference/java/lang/Object#wait())`() ` Causes the current thread to wait until it is awakened, typically by being*notified* or*interrupted*.                                                                                             | ||

## Public constructors

### ECParameterSpec

Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)  

```
public ECParameterSpec (EllipticCurve curve, 
                ECPoint g, 
                BigInteger n, 
                int h)
```

Creates elliptic curve domain parameters based on the specified values.

<br />

|                                    Parameters                                     ||
|---------|--------------------------------------------------------------------------|
| `curve` | `EllipticCurve`: the elliptic curve which this parameter defines. <br /> |
| `g`     | `ECPoint`: the generator which is also known as the base point. <br />   |
| `n`     | `BigInteger`: the order of the generator`g`. <br />                      |
| `h`     | `int`: the cofactor. <br />                                              |

|                                                                Throws                                                                ||
|--------------------------------------------------------------------------------------------------------|------------------------------|
| [NullPointerException](https://developer.android.com/reference/java/lang/NullPointerException)         | if`curve`,`g`, or`n`is null. |
| [IllegalArgumentException](https://developer.android.com/reference/java/lang/IllegalArgumentException) | if`n`or`h`is not positive.   |

## Public methods

### getCofactor

Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)  

```
public int getCofactor ()
```

Returns the cofactor.

<br />

|           Returns           ||
|-------|----------------------|
| `int` | the cofactor. <br /> |

### getCurve

Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)  

```
public EllipticCurve getCurve ()
```

Returns the elliptic curve that this parameter defines.

<br />

|                                                                      Returns                                                                      ||
|-------------------------------------------------------------------------------------------|--------------------------------------------------------|
| [EllipticCurve](https://developer.android.com/reference/java/security/spec/EllipticCurve) | the elliptic curve that this parameter defines. <br /> |

### getGenerator

Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)  

```
public ECPoint getGenerator ()
```

Returns the generator which is also known as the base point.

<br />

|                                                                  Returns                                                                   ||
|-------------------------------------------------------------------------------|-------------------------------------------------------------|
| [ECPoint](https://developer.android.com/reference/java/security/spec/ECPoint) | the generator which is also known as the base point. <br /> |

### getOrder

Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)  

```
public BigInteger getOrder ()
```

Returns the order of the generator.

<br />

|                                                    Returns                                                     ||
|----------------------------------------------------------------------------|------------------------------------|
| [BigInteger](https://developer.android.com/reference/java/math/BigInteger) | the order of the generator. <br /> |