Here is how i propose it will work:
A block has 6 segments
0. Block ID (sequential #)
1. Data
2. Public key
3. Address hash
4. Transactions (just like BTC or LTC)
5. Append

Two block chains exist, a full chain, which has the data block and a lite chain, which has no data block. A given node has full lite chain and as many blocks of full chain as user specified space allows.

Network will accept a request to "change block segments 1 through 3" only from the node that has address which is the result of hashing the published hash using the published key. (think RSA asymmetric keys here)


When ownership of the block is being transferred:

1. Owner, who currently has the private key generates such a hash that when encrypted with public key results in the address of the buyer. (basically owner has to decrypt new address using his 2 private primes)
2. Owner submits the block to the network for update.
3. Miners find such an "append" string that the contents of the parts 1 through 5 match a standard hash.
4. When append is found the block is now accepted by the network.
5. At this point the buyer can request the network to update the block again, but this time the new owner will provide new public key and new hash for his own address, which match his private keys. Owner can also provide new contents for the "Data" segment.

What yall think?