Mobile phones support secure (encrypted) data transfer on the internet (the same as is used on computers). So the level of security for the internet traffic is at the very least equal to computers.
Furthemore the data travelling ota (over the air), is to the best of my knowledge also encrypted. So far all the big players (banks, credit companies etc.) are installing, using and developing mobile payment enabling solutions.
So mobile payment is quite secure in this regard. If you however search for the nfc/rfid credit cards used you will find a lot of security issues.
So "dare I say" that mobile payment is more secure than, for example, credit cards? It certainly seems like it.
Furthermore, depending on the payment type a lot of extra security measures can be adopted.