vei сказал(а):
a wallet with lots of fake money in it is probably just difference currency. like $100 USD is ~$8,200 rupees. if they're showing you screenshots of their wallet or even videos, that's probably it, but there is no way to create fake bitcoin on the blockchain that actually transfers as the txid chain will be ignored and dumped.
maybe i'm misunderstanding what you're asking, but i believe you're asking if you can double spend (send fake btc) in exchange for other crypto. if so, to exploit any decentralized blockchain, you'd have to own 51% of the mining pool so that your fraudulent txid stays ahead in the chain and doesn't get forked.
you could technically recompile bitcoin and change the mining fee to 0 and then if you have the crypto, your transaction will show up as sent but eventually be ignored when all miners ignore it. it would never confirm tho, so no exchange would cash you out, as most even wait for 6 confirmations before considering a transaction paid.
if i'm wrong, let me know because i'm more than happy to learn.