Public Key Encryption (PKE)
===========================

**Data Types**:

:PKEEncKey: The RSA public key for public-key encryption with RSA.
:PKEDecKey: The RSA private key, used for RSA decryption.

**Functions**:

.. function:: PKEKeyGen() (PKEEncKey, PKEDecKey, error)

    Generate a 2048-bit RSA key pair for public-key encryption.

    :rtype: PKEEncKey, PKEDecKey, error

.. function:: PKEEnc(ek PKEEncKey, plaintext []byte) ([]byte, error)

    Use the RSA public key to encrypt a message.

    :param ek: RSA encryption (public) key
    :type ek: PKEEncKey
    :param plaintext: Message to encrypt, no longer than 126 bytes
    :type plaintext: []byte

    :rtype: []byte, error

.. function:: PKEDec(dk PKEDecKey, ciphertext []byte) ([]byte, error)

    Use the RSA private key to decrypt a ciphertext.

    :param ek: RSA encryption (private) key
    :type ek: PKEDecKey
    :param ciphertext: Message to decrypt
    :type ciphertext: []byte

    :rtype: []byte, error

.. warning::
    PKEEnc does not support very long plaintext.