SipHash128 (Bouncy Castle Library 1.85 API Specification)
Date: 2026-07-12

org.bouncycastle.crypto.macs

## Class SipHash128

- java.lang.Object
- - org.bouncycastle.crypto.macs.SipHash
  - - org.bouncycastle.crypto.macs.SipHash128

- All Implemented Interfaces:
    Mac

      public class SipHash128
      extends SipHash

  Implementation of SipHash with 128 bit output.

  Based on the `SipHash` and the C reference implementation https://github.com/veorq/SipHash.

- - ### Field Summary

    - ### Fields inherited from class org.bouncycastle.crypto.macs.SipHash

      `c, d, k0, k1, m, v0, v1, v2, v3, wordCount, wordPos`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `SipHash128()` SipHash128-2-4
    `SipHash128(int c, int d)` SipHash128-c-d

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `long` | `doFinal()`
    `int` | `doFinal(byte[] out, int outOff)` Compute the final stage of the MAC writing the output to the out parameter.
    `java.lang.String` | `getAlgorithmName()` Return the name of the algorithm the MAC implements.
    `int` | `getMacSize()` Return the block size for this MAC (in bytes).
    `void` | `reset()` Reset the MAC.

    - ### Methods inherited from class org.bouncycastle.crypto.macs.SipHash

      `applySipRounds, init, processMessageWord, rotateLeft, update, update`

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Constructor Detail

    - #### SipHash128

          public SipHash128()

      SipHash128-2-4

    - #### SipHash128

          public SipHash128(int c,
                            int d)

      SipHash128-c-d
      Parameters:
        `c` - the number of compression rounds
        `d` - the number of finalization rounds

  - ### Method Detail

    - #### getAlgorithmName

          public java.lang.String getAlgorithmName()

      Description copied from interface: `Mac`
      Return the name of the algorithm the MAC implements.
      Specified by:
        `getAlgorithmName` in interface `Mac`
      Overrides:
        `getAlgorithmName` in class `SipHash`
      Returns:
        the name of the algorithm the MAC implements.

    - #### getMacSize

          public int getMacSize()

      Description copied from interface: `Mac`
      Return the block size for this MAC (in bytes).
      Specified by:
        `getMacSize` in interface `Mac`
      Overrides:
        `getMacSize` in class `SipHash`
      Returns:
        the block size for this MAC in bytes.

    - #### doFinal

          public long doFinal()
                       throws DataLengthException,
                              java.lang.IllegalStateException

      Overrides:
        `doFinal` in class `SipHash`
      Throws:
        `DataLengthException`
        `java.lang.IllegalStateException`

    - #### doFinal

          public int doFinal(byte[] out,
                             int outOff)
                      throws DataLengthException,
                             java.lang.IllegalStateException

      Description copied from interface: `Mac`
      Compute the final stage of the MAC writing the output to the out parameter.

      doFinal leaves the MAC in the same state it was after the last init.

      Specified by:
        `doFinal` in interface `Mac`
      Overrides:
        `doFinal` in class `SipHash`
      Parameters:
        `out` - the array the MAC is to be output to.
        `outOff` - the offset into the out buffer the output is to start at.
      Throws:
        `DataLengthException` - if there isn't enough space in out.
        `java.lang.IllegalStateException` - if the MAC is not initialised.

    - #### reset

          public void reset()

      Description copied from interface: `Mac`
      Reset the MAC. At the end of resetting the MAC should be in the in the same state it was after the last init (if there was one).
      Specified by:
        `reset` in interface `Mac`
      Overrides:
        `reset` in class `SipHash`