It appears to me that if there's a blockchain, then it's there for everyone to review. Your bits and bytes stay forever. Actually, make that megabytes. So putting encrypted data onto a public blockchain meant for open access is going against the purpose of the steem blockchain.

Please put your messages onto your own, freestanding blockchain. In fact, why do you need a block chain at all. Who cares if your cat is lost or you just ate a tuna fish sandwich five years from now?

D o   N o t   c l o g   u p   t h e   s t e e m   b l o c k  c h a i n   w i t h   s u c h   t r i v i a l   n o n s e n s e .