To answer that question the best is to explain the SELL process:
- The user want to SELL bitcoin
- The bitcoin machine provides a fresh new public address for the transfer
- The user sends the bitcoins to that address
- Bitcoin network detects the transfer sent and issues a ticket with a confirmation code
- The user waits for some minutes while the transaction is confirmed (the ATM can be used by other people)
- After some confirmations the user scans the “ticket with the confirmation code” in the QR reader.
- The ATM validates the confirmation and gives money out if everything is valid.
Optionally the operator can activate the extra security option. In the step 4 the machine can be configured so that a PIN code is inserted. This PIN code is then required later on in step 6. This is made in case a camera would record the ticket received.