def encipher_rsa(pt, puk):
    """
    In RSA, a message `m` is encrypted by computing
    `m^e` (mod `n`), where ``puk`` is the public key `(n,e)`.

    Examples
    ========

    >>> from sympy.crypto.crypto import encipher_rsa, rsa_public_key
    >>> p, q, e = 3, 5, 7
    >>> puk = rsa_public_key(p, q, e)
    >>> pt = 12
    >>> encipher_rsa(pt, puk)
    3

    """
    n, e = puk
    return pow(pt, e, n)