Module java.base
Package java.security

# Interface PrivateKey

All Superinterfaces:
  `Destroyable`, `Key`, `Serializable`

All Known Subinterfaces:
  `DHPrivateKey`, `DSAPrivateKey`, `ECPrivateKey`, `EdECPrivateKey`, `RSAMultiPrimePrivateCrtKey`, `RSAPrivateCrtKey`, `RSAPrivateKey`, `XECPrivateKey`

public interface PrivateKey extends Key, Destroyable
A private key. The purpose of this interface is to group (and provide type safety for) all private key interfaces.

Note: The specialized private key interfaces extend this interface. See, for example, the `DSAPrivateKey` interface in `java.security.interfaces`.

Implementations should override the default `destroy` and `isDestroyed` methods from the `Destroyable` interface to enable sensitive key information to be destroyed, cleared, or in the case where such information is immutable, unreferenced. Finally, since `PrivateKey` is `Serializable`, implementations should also override `ObjectOutputStream.writeObject(java.lang.Object)` to prevent keys that have been destroyed from being serialized.

Since:
  1.1
See Also:
  - `Key`
  - `PublicKey`
  - `Certificate`
  - `Signature.initVerify(java.security.PublicKey)`
  - `DSAPrivateKey`
  - `RSAPrivateKey`
  - `RSAPrivateCrtKey`

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `static final long`
  `serialVersionUID`
  Deprecated.
  A `serialVersionUID` field in an interface is ineffectual.

- ## Method Summary

  ### Methods declared in interface javax.security.auth.Destroyable

  `destroy, isDestroyed`

  ### Methods declared in interface java.security.Key

  `getAlgorithm, getEncoded, getFormat`

- ## Field Details

  - ### serialVersionUID

    @Deprecated static final long serialVersionUID
    Deprecated.
    A `serialVersionUID` field in an interface is ineffectual. Do not use; no replacement.
    The class fingerprint that is set to indicate serialization compatibility with a previous version of the class.
    See Also:
      - Constant Field Values