Bitcoin is decentralized at it's core and it's protocol has been designed to ensure that no 3rd party ever needs to hold bitcoins. The blockchain is a perfect database that can be viewed by everyone.
Why does the 3rd party ever need to hold bitcoins and keep a separate database? Why does any exchange need to hold bitcoins?
All they need to do is function as a trusted 3rd party who fairly arbitrates and manages the final transaction.
I agree completly.
There are people concerned about "polluting" the blockchain with exess information, totally unwarranted considering the geometric growth of harddrive capacity exeeds moors law.
The initial idea is just to make a blockchain that, instead of coins, has information of which briefcase owns an asset.
Ie. this blockchain would not include coin transactions, but it would include asste transaction.
Let's make an example: You have a wal.. er briefcase which has generated 10000 assets named "KONIAINC". You have sold 100 of them to someone, who tells he's address is SfdfhHDfHjjfJDfj1212JJFDfk. You make a transaction where you give 100 of your assets from your briefcase to that addressand sign it. This transaction is assured just like bitcoin transaction.
So basicly it's a bitcoin, but replace word "coin" with "share" and "wallet" with "briefcase".
By linking stock blockchain to bitcoin blockchain is not necessary, but it could make certain things easier.