•   over 11 years ago

Way to cancel a value message?

I think I know the answer to this (no)

I'm not talking about reverting a transaction. That can be done just by creating a new transaction in the opposite direction.

I'm talking about creating a Value Message, and then the user deciding that they don't want to continue with it. Can it be revoked and the balance reapplied to their account?

I think the answer is no, but the reason I ask is because creating a Value Message is I/O bound. It's slow, whether it's via the local SD card, or remote hosted. Typically, you avoid the impact of such transactions by performing them asynchronously and pre-loading them outside your main UI thread. However, if the user then decides to back out of the transaction, that value is "lost."

In the current implementation, Value Messages are created after the user confirms the transaction. This means there's some lag while it is created, but it does ensure that the message cannot be cancelled or lost.

Anyway, hoping someone can propose a solution that I haven't thought of.


  •   •   over 11 years ago

    That's correct; there's no way to cancel the Value Message. The easiest way to explain why is to realize that Messages are just bytes, and I can send you a copy of them to deposit while still keeping a copy to cancel. Because there's no central system to keep track of us both using our copy, we've cheated the system.

    Users will need to understand that they cannot back out of the transaction in this manner; transactions for goods and services will almost require that the Payer receives their good or service first, providing an impetus on the Payee to accept the Value Message. If the Payer generates the Value Message before receiving said goods/services, the Payee could back out after the message is generated, maliciously or otherwise. They're under no obligation to process the Message and return it; in fact, they could offer to take the Payer's otherwise-useless Message and send it back for a small fee. And then refuse to send it back, too.

    Here's hoping that MintChip Value becomes considered legal tender, to at least require vendors to accept it for purposes of payment. While MintChip is a good approximation of a digital wallet, its inability to shove that $20 bill back in as easily as it came out is indeed a limitation.

  •   •   over 11 years ago

    Hmm, I didn't think about it like that, and of course, that makes a lot of sense.

    Maybe as MintChip matures, the latency can be reduced.

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