Is it possible to add coins to a wallet that were never mined?

Question

Since Monero's transactions are basically anonymous, is it possible to create coins that were never mined, so they don't originate in any coinbase? I understand that it's possible to add up all the coinbase amounts to ascertain some supply figure of the currency, but what about theoretical coins that could be created outside the coinbase, particularly if they are facilitated by Monero's opaque blockchain?

Is this hack theoretically possible?

Answer 1

It must be impossible. The underlying math is such that it is provably impossible. So no, it's not theoretically possible. Theoretical possibility would mean a broken coin.

I could imagine 2 ways to create coins in a TX:

• Successfully double-spend the same output. However, this is not possible because of the key images mechanism.
• Cheat the sum(in) == sum(out) equation, and make an output of greater amount than you have the 'right' to. However, this is not possible because of Pedersen commitment and range proofs.

Answer 2

That is not possible in Monero but is a definite problem in other coins such as Zcash.