We'd still want to validate the given key matches the key size for the given block and we'd still want an attribute that exposes the actual key size of the cipher so we aren't parsing names to figure it out. So it'd be like

```python
class TDES64(object):
    block_size = 64
    key_size = 64
    name = "3DES"

    def __init__(self, key):
        self.key = key
        super(TDES64, self).__init__()
        # Check self.key matches the key size
```

So I think the biggest thing the ``TDES64`` vs ``TDES`` buys us is the ability to flag cipher key sizes as weak while other key sizes of the same size are strong. I'm -0 on it but if you feel strongly about it then it probably makes sense to bring it up on the mailing list.