You are doing everything on another person's gadget. Any verification Square can come up with, can be bypassed by simply not implementing it.
Verified icon? Easy JPG
Encoded credit card #s? Who said the fraudsters would need to use your tool?
Square Verified badge? Easily copied.
It basically boils down to trust issue, early on, consumers will just be unaware of how vulnerable they are, but then stories will start popping up all over the place about how so and so, paid with a credit card for a taxi ride using Square, and then got hit with $5K in credit card fraud.
As BigO said (or implied at least) above any such device needs to be mine. I should get a transaction ID from the seller and use an encrypted text message or other interaction with my bank to forward the money to the seller - on completion they see their tx-ID as paid and I go on my way with my acquired goods.
The Square system is like me handing over a pot with all my money in it and saying "take what you like". Whilst the above is akin to me passing the money to an esscrow (my bank) and them checking it is OK and telling the receiver of the funds.
Sure a fraudster can get hold of a fake merchant ID and encode the transaction value, ID and their merchant ID with an acquired private key - but that merchant ID can just be locked when fraud is spotted and decrypting the data off the wire is going to require lots of resources.
You are doing everything on another person's gadget. Any verification Square can come up with, can be bypassed by simply not implementing it.
Verified icon? Easy JPG
Encoded credit card #s? Who said the fraudsters would need to use your tool?
Square Verified badge? Easily copied.
It basically boils down to trust issue, early on, consumers will just be unaware of how vulnerable they are, but then stories will start popping up all over the place about how so and so, paid with a credit card for a taxi ride using Square, and then got hit with $5K in credit card fraud.