__init__(self, dec_keys=[], verify_keys=[], IV=None)
(Constructor)

Initialize the decryption cipher. The parameters used here are
the following:
    
    dec_keys - Keys to try for decrypting the stream. The key
               which was actually used for decryption of the
               stream is assigned to the decryptionKey property
               of the instance.
    verify_keys - Keys which are used to verify the signature(s)
                  that are appended to the cipher packet. The key
                  which was actually used for verifying the
                  signature is assigned to the verifyKey property
                  of the instance.
    IV - In case you passed a user-defined block chaining mode IV
         to the encryption cipher class, you must also pass it
         to the decryption. Special value None means to use the
         default IV defined in _Imports.py.
         
All arguments except dec_keys and verify_keys have safe defaults.

__new__(S, ...)

Returns:

a new object with type S, a subtype of T