[quote=“crypto_coiner, post:27, topic:3247”]Very intriguing project.
A couple of questions.
- Where are the messages stored?[/quote]
Messages are stored in a parasitic cloud storage initially, and then eventually a sidechain/bittorrent as well.
The Peercoin blockchain stores the key pointing to the external datastore, as well as verifies the user attached to an externally stored message.
Wait and see. 
Interesting historical link of the day:
In that thread, Satoshi speaks about the idea of sending messages via the blockchain. Quotes:
I very much wanted to find some way to include a short message, but the problem is, the whole world would be able to see the message. As much as you may keep reminding people that the message is completely non-private, it would be an accident waiting to happen.Unfortunately, ECDSA can only sign signatures, it can’t encrypt messages, and we need the small size of ECDSA. RSA can encrypt messages, but it’s many times bigger than ECDSA.
We can figure out the best way to do this much later. It could use a separate (maybe existing) e-mail or IM infrastructure to pass messages, and instead of RSA, maybe just put a hash of the message in the transaction to prove that the transaction is for the order described in the message. The message would have to include a salt so nobody could brute force the hash to reveal a short message.