ImportError: No module named Crypto.PublicKey如何解决？

Question

sudo python RsaCtfTool.py --publickey key.pem --uncipherfile cipher.bin --attack fermat

Traceback (most recent call last):
  File "RsaCtfTool.py", line 19, in <module>
    from Crypto.PublicKey import RSA
ImportError: No module named Crypto.PublicKey

如上