This is done through the creation of secondary wallets
with unique private keys that enable the transfers of exact amounts.
In order to do this, PayPal proposed a way to create secondary wallets with their
own unique private keys for buyers and sellers.
With PayPal's system, a secondary wallet has
unique private keys.
Users also determine ownership of these assets via the use of
unique private keys.
The secondary wallets of users, as described in the official patent, would allow
the unique private keys of buyers and sellers to be transferred behind the scenes, to prevent every transaction from being included in blocks and broadcasted to the public Blockchain.