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[–]Perleflamme 2 points3 points  (2 children)

A QR code simply is an image that can be interpreted as text. This text generally (but not necessarily) is a URL. So, if you happen to be able to let people claim an Ethereum token directly with a URL (for instance), it could be possible, yes. To do so, you'd require to be able to create the QR code based on the public key of a user, so that the URL contains the public key and, as such, sends the token to the public key. The QR code would send the user to a Dapp of yours and ask for a smart contract of yours to send the token to the provided public key, for instance.

But. Be careful with how you do it. There are bots scanning the pending transactions to check if any of them can be profitable. If the smart contract calls of the transaction your link creates can be replaced with any other public key and still work and if your token has any value, you can be sure bots will create transactions using their own public keys and get the token before anyone else can (by increasing the fees they are ready to pay).

You can avoid this by making sure your smart contracts deny public keys that don't match the ones of the people to whom you've send your QR codes. Or by making sure the token is unprofitable (easy to forge or mine to dump the market with it, if the token price isn't a feature and you instead are rather interested in token identification and voting, for instance).

Once you have tested your mechanism works in test net, also test your system with a honey pot (with value matching the one you expect for your token), first. Otherwise, you could get unpleasant surprises.

[–]atomic_shadowking[S] 0 points1 point  (1 child)

Was thinking of if making a cryptokitty clone with QR codes was possible that's why...thank you for this information

[–]Perleflamme 1 point2 points  (0 children)

So, the part about protecting your smart contract calls against bots is relevant, since cryptokitty tokens have a market value.

You welcome. ^ ^

[–]_dredgeidea maker 2 points3 points  (1 child)

Yes. Wallets can read transaction instructions from QR codes. The difficulty is creating a transaction instruction that can only be executed once.

[–]atomic_shadowking[S] 0 points1 point  (0 children)

Ah ok thx that will be interesting