Will i lose my bitcoin in this case?
No since you send the coins to yourself you just have to wait for a confirmation in the receiving wallet as well as the sending wallet in order to avoid that the wallets get confused. The nature of the attack is only that the transaction ID is modified but the coins still go to the same place and come from the same place. Bitcoin dont actually go anywhere, but lets just assume that it works like that. Your wallet will see the transaction twice. The one you create and its modified twin, both are identical but have different names. Once one twin is confirmed the other becomes invalid as bitcoins can not be spend twice. You have to wait for this confirmation in order to avoid issues, nothing else. If your wallet still shows the wrong balance once one of the TX is confirmed just reset it. How this works depends on your wallet.
But even if he didn't send coins to himself, he wouldn't be in danger of losing coins. If he sent coins to somebody as a payment, the same scenario that you have described above should just be respected.
Yes, but OP might be in danger if they received the coins.
As I got it with these malleability attacks, only need that we need to respect is being patient and waiting for that first confirmation, in order not to send another payment and cause the double spending problem.
Yes, but consider the follow scenario. Alice sends coins to Bob. They know eachother so there is no trust issue. They both consider the TX done and confirmed the moment it was broadcasted. A short time later Alice sends coins to pavs94 and the wallet Alice uses selects the unspend change from the transaction to Bob. Under normal circumstances this would not be an issue because the TX from A to B will confirm with the TX ID it had when Alice issue it. Due to the malleability attack however it might be the twin that gets confirmed. As such the follow up transaction from Alice to pavs94 that uses the unconfirmed change will get invalid. It would point to a transaction that is now invalid and thus can never confirm.
That is why its important to wait for one confirmation not only on the receiving end, but also on the sending end. Well, unless you hand pick the inputs you use and avoid the above issue yourself, but that is not common as most wallets do not even allow such a thing.
OK I see. I understand now! You are very good in explaining stuff! Thanks a lot!
