1. You get proven semantic security - that is nobody can learn anything other than the message length - for whatever you're splitting. If you divide up an AES k

1. You get proven semantic security - that is nobody can learn anything other than the message length - for whatever you're splitting. If you divide up an AES key into chunks an attacker would get partial knowledge of the key from one of those chunks. 2. You get to pick how many parts are needed to reconstruct, e.g. three of seven parts required.