Questions tagged [replay-attack]

A type of an attack against the security of a system by recording its encrypted communication, and later replaying it in unmodified or slightly modified form.

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How does Bitcoin Cash implement replay protection?

Bitcoin Cash says that they are providing replay protection for their fork. How does this replay protection work?
Murch
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What is transaction replay and replay protection?

With everyone and their dog making new blockchains forked from the bitcoin blockchain, there is a lot of talk about replay protection. What is a transaction replay? What does replay protection do?
Dr.Haribo
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What would happen if you send Bitcoin (BTC) to a Bitcoin Cash (BCH, aka BCC) address?

Could someone please explain what happens if someone sends bitcoin to a Bitcoin Cash address after the August 1st fork? Would there be a way to recover them?
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What should I do if my friend runs a Bitcoin business but doesn't understand how it works?

My friend doesn't listen to his head of engineering and doesn't fully understand how decentralized consensus based systems like Bitcoin really work. He seems to think a new untested/buggy implementation with conflicting consensus rules can be made…
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What is the best way to prevent replay attacks in the event of a bitcoin hard fork?

I originally thought it would be relatively simple to add replay attack protection (change something about how the tx hash is generated) in the event of a fork. But the BU folks mentioned that this would break SPV clients (including many mobile…
Brian Armstrong
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after hard fork won't every new transaction go on both chains?

I don't understand why I'm reading that after a hard fork, the existing transactions would be on both chains but the new transactions will only be on one or the other (resulting in 2 different chains, thus an altcoin). Won't even new transactions…
RentFree
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How does Bitcoin Gold implement replay protection?

The creators of Bitcoin Gold claim that they have implemented full replay protection. How does this replay protection work?
Andrew Chow
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Is there a time limit how long a signed transaction is valid?

When splitting coins from a hard fork and signing the transaction on the forked coin, is there a time/block limit when the transaction gets invalid on the BTC chain, so a potentially possible replay attack gets invalid forever? Imagine this…
A1m
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If Btc2x doesn't have replay protection does that mean all transactions can be automatically replayed in btc2x?

I believe btc will have a lot higher economic activity at the time of the fork. If anyone sends funds in btc, what stops someone who don't like btc2x to just replay that same transaction on btc2x? This will shuffle around funds, to different…
Kristoffer Nolgren
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How does the Segwit2x fork implement replay protection?

The creators of the Segwit2x fork claim that they are working on some sort of replay protection. What replay protection do they have and how does this replay protection work?
Andrew Chow
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Replay attacks: can a coinbase transaction be replayed?

I'm pretty sure that I understand how replay attacks work: A malicious node takes a valid transaction from chain A, and replays it on chain B. Other nodes on chain B see the transaction as valid and therefore it is included in both chains, instead…
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How was Ethereum hard fork's replay attack was handled?

On etherum, there was a hard fork which resulted in ETH and ETC. My reading indicates that it suffered problem of replay-attack. Question: How was this problem resolved for Ethereum? In my understanding, replay-attack protection requires another…
Yuki Inoue
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What prevents a malicious user creating a new transaction using signatures of an old mined transaction if the inputs have the exact same balance?

I am NOT talking about double spending. I am talking about this type of scenario: Let's say address A has 1 BTC balance initially. A valid transaction is created and for simplicity's sake, assume all the balance is transferred to address B in a…
D. Doshi
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Why do we refer to previous transactions in each transaction?

Isn't it enough to just have the Input Address, Output Address, Amount and Signature for each transaction?
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Limit tx to SegWit1x or 2x chain

Given the lack of replay protection when the SegWit2x fork splits off a different chain is there a safe mechanism to broadcast a tx so that it will only be accepted by the 1x or 2x chain nodes? If the answer is no would an option be to run both a…
sipsorcery
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