Quote from: mjglqw on November 08, 2019, 08:24:33 AM

As far as I know, the receiver cant get tricked assuming:

The receiver has had his bitcoin address ready(probably pre-copied address to his notes app, or a screenshotted QR code)
The receiver is viewing his bitcoin address through a reputable and untampered app(Mycelium, Electrum, etc)

a sybil attack is theoretically possible. if the sender sets up lots of malicious nodes (or electrum servers), the receiver might connect to them and become separated from the honest network. this opens them up to double spending, de-anonymization, and DOS attacks.
https://en.bitcoin.it/wiki/Weaknesses#Sybil_attack

Quote from: johnwhitestar on November 08, 2019, 08:33:55 AM

I was thinking about the receiver that is using bitcoin-qt wallet.
So if he connects to the forked BTC blockchain he'll download wrong blocks then the sender will send him BTC, a valid transaction on the forked blockchain, and then the receiver will go home, connect to the right blockchain and see the transaction has never occurred.

the attack is theoretically possible but extremely unlikely because it requires mining blocks at the current difficulty level.