'Encrypt a piece of data with RSA.
:Parameter plaintext: The piece of data to encrypt with RSA. It may not
be numerically larger than the RSA module (**n**).
:Type plaintext: byte string or long
:Parameter K: A random parameter (*for compatibility only. This
value will be ignored*)
:Type K: byte string or long
:attention: this function performs the plain, primitive RSA encryption
(*textbook*). In real applications, you always need to use proper
cryptographic padding, and you should not directly encrypt data with
this method. Failure to do so may lead to security vulnerabilities.
It is recommended to use modules
`Crypto.Cipher.PKCS1_OAEP` or `Crypto.Cipher.PKCS1_v1_5` instead.
:Return: A tuple with two items. The first item is the ciphertext
of the same type as the plaintext (string or long). The second item
is always None.'

def encrypt(self, plaintext, K):

    return pubkey.pubkey.encrypt(self, plaintext, K)
