KeyEncapsulation (Bouncy Castle Library 1.85 API Specification)
Date: 2026-07-12

org.bouncycastle.crypto

## Interface KeyEncapsulation

- All Known Implementing Classes:
    ECIESKeyEncapsulation, RSAKeyEncapsulation

  Deprecated.
  use `EncapsulatedSecretGenerator` and `EncapsulatedSecretExtractor`

      public interface KeyEncapsulation

  The basic interface for key encapsulation mechanisms.

- - ### Method Summary

    All Methods Instance Methods Abstract Methods Deprecated Methods
    Modifier and Type | Method and Description
    --- | ---
    `CipherParameters` | `decrypt(byte[] in, int inOff, int inLen, int keyLen)` Deprecated. Decapsulate an encapsulated session key.
    `CipherParameters` | `encrypt(byte[] out, int outOff, int keyLen)` Deprecated. Encapsulate a randomly generated session key.
    `void` | `init(CipherParameters param)` Deprecated. Initialise the key encapsulation mechanism.

- - ### Method Detail

    - #### init

          void init(CipherParameters param)

      Deprecated.
      Initialise the key encapsulation mechanism.

    - #### encrypt

          CipherParameters encrypt(byte[] out,
                                   int outOff,
                                   int keyLen)

      Deprecated.
      Encapsulate a randomly generated session key.

    - #### decrypt

          CipherParameters decrypt(byte[] in,
                                   int inOff,
                                   int inLen,
                                   int keyLen)

      Deprecated.
      Decapsulate an encapsulated session key.