Package org.bouncycastle.pqc.crypto.rainbow

## Class RainbowSigner

- java.lang.Object
- - org.bouncycastle.pqc.crypto.rainbow.RainbowSigner

- All Implemented Interfaces:
    `MessageSigner`

      public class RainbowSigner
      extends java.lang.Object
      implements MessageSigner

  It implements the sign and verify functions for the Rainbow Signature Scheme. Here the message, which has to be signed, is updated. The use of different hash functions is possible.

  Detailed information about the signature and the verify-method is to be found in the paper of Jintai Ding, Dieter Schmidt: Rainbow, a New Multivariable Polynomial Signature Scheme. ACNS 2005: 164-175 (https://dx.doi.org/10.1007/11496137_12)

- - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `RainbowSigner()` |

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `byte[]` | `generateSignature​(byte[] message)` | This function signs the message that has been updated, making use of the private key.
    `void` | `init​(boolean forSigning, CipherParameters param)` | initialise the signer for signature generation or signature verification.
    `boolean` | `verifySignature​(byte[] message, byte[] signature)` | This function verifies the signature of the message that has been updated, with the aid of the public key.

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

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

- - ### Constructor Detail

    - #### RainbowSigner

          public RainbowSigner()

  - ### Method Detail

    - #### init

          public void init​(boolean forSigning,
                           CipherParameters param)

      Description copied from interface: `MessageSigner`
      initialise the signer for signature generation or signature verification.
      Specified by:
        `init` in interface `MessageSigner`
      Parameters:
        `forSigning` - true if we are generating a signature, false otherwise.
        `param` - key parameters for signature generation.

    - #### generateSignature

          public byte[] generateSignature​(byte[] message)

      This function signs the message that has been updated, making use of the private key.

      For computing the signature, L1 and L2 are needed, as well as LES should be solved for each layer in order to find the Oil-variables in the layer.

      The Vinegar-variables of the first layer are random generated.

      Specified by:
        `generateSignature` in interface `MessageSigner`
      Parameters:
        `message` - the message
      Returns:
        the signature of the message.

    - #### verifySignature

          public boolean verifySignature​(byte[] message,
                                         byte[] signature)

      This function verifies the signature of the message that has been updated, with the aid of the public key.
      Specified by:
        `verifySignature` in interface `MessageSigner`
      Parameters:
        `message` - the message
        `signature` - the signature of the message
      Returns:
        true if the signature has been verified, false otherwise.