# XECPrivateKey Added in[API level 33](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) # XECPrivateKey ``` interface XECPrivateKey : PrivateKey, XECKey ``` |----------------------------------------------------------------------------------------------------------------------------------| | [java.security.interfaces.XECPrivateKey](https://developer.android.com/reference/kotlin/java/security/interfaces/XECPrivateKey#) | An interface for an elliptic curve private key as defined by RFC 7748. These keys are distinct from the keys represented by`ECPrivateKey`, and they are intended for use with algorithms based on RFC 7748 such as the XDH`KeyAgreement`algorithm. An XEC private key is an encoded scalar value as described in RFC 7748. The decoding procedure defined in this RFC includes an operation that forces certain bits of the key to either 1 or 0. This operation is known as "pruning" or "clamping" the private key. Arrays returned by this interface are unpruned, and implementations will need to prune the array before using it in any numerical operations. ## Summary | Inherited constants || |---|---| | From class[PrivateKey](https://developer.android.com/reference/kotlin/java/security/PrivateKey.html#) |------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | [Long](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-long/index.html) | [serialVersionUID](https://developer.android.com/reference/kotlin/java/security/PrivateKey.html#serialVersionUID:kotlin.Long)
The class fingerprint that is set to indicate serialization compatibility with a previous version of the class.
| || | Public methods || |------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | abstract[Optional](https://developer.android.com/reference/kotlin/java/util/Optional.html#)\<[ByteArray](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-byte-array/index.html)!\>! | [getScalar](https://developer.android.com/reference/kotlin/java/security/interfaces/XECPrivateKey#getScalar())`()` Get the scalar value encoded as an unpruned byte array. | | Inherited functions || |---|---| | From class[Destroyable](https://developer.android.com/reference/kotlin/javax/security/auth/Destroyable.html#) |------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | [Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [destroy](https://developer.android.com/reference/kotlin/javax/security/auth/Destroyable.html#destroy())`()`
Destroy this`Object`. Sensitive information associated with this`Object`is destroyed or cleared. Subsequent calls to certain methods on this`Object`will result in an`IllegalStateException`being thrown. The default implementation throws`DestroyFailedException`. Android note: Up to and including API 25 this method did not have a default implementation. Implementations of this interface must provide a concrete implementation of this method in order to work on older versions of Android.
| | [Boolean](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-boolean/index.html) | [isDestroyed](https://developer.android.com/reference/kotlin/javax/security/auth/Destroyable.html#isDestroyed())`()`
Determine if this`Object`has been destroyed. The default implementation returns false. Android note: Up to and including API 25 this method did not have a default implementation. Implementations of this interface must provide a concrete implementation of this method in order to work on older versions of Android.
| || | From class[Key](https://developer.android.com/reference/kotlin/java/security/Key.html#) |------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | [String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)! | [getAlgorithm](https://developer.android.com/reference/kotlin/java/security/Key.html#getAlgorithm())`()`
Returns the standard algorithm name for this key. For example, "DSA" would indicate that this key is a DSA key. See the key related sections (KeyFactory, KeyGenerator, KeyPairGenerator, and SecretKeyFactory) in the[Java Security Standard Algorithm Names Specification](https://docs.oracle.com/en/java/javase/17/docs/specs/security/standard-names.html)for information about standard key algorithm names.
| | [ByteArray](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-byte-array/index.html)! | [getEncoded](https://developer.android.com/reference/kotlin/java/security/Key.html#getEncoded())`()`
Returns the key in its primary encoding format, or null if this key does not support encoding.
| | [String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)! | [getFormat](https://developer.android.com/reference/kotlin/java/security/Key.html#getFormat())`()`
Returns the name of the primary encoding format of this key, or null if this key does not support encoding. The primary encoding format is named in terms of the appropriate ASN.1 data format, if an ASN.1 specification for this key exists. For example, the name of the ASN.1 data format for public keys is*SubjectPublicKeyInfo* , as defined by the X.509 standard; in this case, the returned format is`"X.509"`. Similarly, the name of the ASN.1 data format for private keys is*PrivateKeyInfo* , as defined by the PKCS #8 standard; in this case, the returned format is`"PKCS#8"`.
| || | From class[XECKey](https://developer.android.com/reference/kotlin/java/security/interfaces/XECKey) |---------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | [AlgorithmParameterSpec](https://developer.android.com/reference/kotlin/java/security/spec/AlgorithmParameterSpec.html#)! | [getParams](https://developer.android.com/reference/kotlin/java/security/interfaces/XECKey#getParams())`()`
Returns the algorithm parameters associated with the key.
| || ## Public methods ### getScalar Added in[API level 33](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` abstract fun getScalar(): Optional! ``` Get the scalar value encoded as an unpruned byte array. A new copy of the array is returned each time this method is called. | Return || |--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | [Optional](https://developer.android.com/reference/kotlin/java/util/Optional.html#)<[ByteArray](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-byte-array/index.html)!>! | the unpruned encoded scalar value, or an empty Optional if the scalar cannot be extracted (e.g. if the provider is a hardware token and the private key is not allowed to leave the crypto boundary). |