cedric posted this 7 years ago
Hello,
I have a stupid question but I would really like to have an answer.
With ringCT I understand that nobody can see the amount of XMR in transactions except the sender and the receiver.
Now let's assume I have an UTXO with 0.001 XMR. What prevents me to broadcast transactions on the network with 0.01 XMR fees, thus sending negative balances (0.001 - 0.01 = - 0.099), spamming the network and creating new XMR from thin air. Of course I will not profit these XMR they will go to the miners, but I can still spam the network? If I am a miner I would also have incentive to do so...
Maybe a stupid question, but how can we know there is enough XMR to pay miner fees (so we know the transaction is valid)?
Hi, cedric.
The problem you described is central to the Confidential Transactions scheme (common to both Maxwell's original version and RingCT) which is solved by a technique called range proof. Here's the original CT paper (https://people.xiph.org/~greg/confidential_values.txt) that explains it, and here's an answer I posted to StackExchange (https://monero.stackexchange.com/q/3035/506) that explains it differently.
Hope it helps!