The use of time blocks in the transaction process has the effect of producing a natural, in-built 2-factor authentication system.
This forces the transactions to occur in real-time.
The first factor requires the transaction to be cryptographically signed by both the expecting sender and receiver.
The second factor results from the sender having to send the proposed transfer code to the expecting receiver, through an agreed transmission medium (E.g. Sms, internet messaging apps, etc), in order to correctly sign the details using the expected receiver’s wallet address (public key).
The transaction expires if this process is not completed within the assigned time block, E.g. 90s.