'Returns the name of the encryption mode to use.
:return:
A unicode string from one of the following: "cbc", "ecb", "ofb",
"cfb", "wrap", "gcm", "ccm", "wrap_pad"'

@property
def encryption_mode(self):

    encryption_algo = self[u'algorithm'].native
    if (encryption_algo[0:7] in set([u'aes128_', u'aes192_', u'aes256_'])):
        return encryption_algo[7:]
    if (encryption_algo[0:6] == u'pbes1_'):
        return u'cbc'
    if (encryption_algo[0:7] == u'pkcs12_'):
        return u'cbc'
    if (encryption_algo in set([u'des', u'tripledes_3key', u'rc2', u'rc5'])):
        return u'cbc'
    if (encryption_algo == u'pbes2'):
        return self[u'parameters'][u'encryption_scheme'].encryption_mode
    raise ValueError(unwrap(u'\n                                                Unrecognized    encryption    algorithm    "%s"\n                                                ', encryption_algo))
