11
votes
What is Monero's mechanism for defending against a double-spend attack?
Double spends are prevented by the use of key images, which are sent along with each output being spent in a transaction, and which are checked for uniqueness before allowing the transaction.
In the ...
- 34.9k
10
votes
Accepted
What is Monero's mechanism for defending against a double-spend attack?
Each transaction generates a key image. In the CryptoNote protocol, key images used more than once are rejected by the blockchain as double-spends. When a new transaction is received, the miner need ...
- 2,501
8
votes
How does the recent patched key image exploit work in practice?
Looks like it was being exploited on Bytecoin
For example, these 2 transactions spend the output 26e8958fc2b227b045c3f489f2ef98f0d5dfac05d3c63339b13802886d53fc05 twice!
http://chainradar.com/bcn/...
- 19.9k
7
votes
Accepted
How does the recent patched key image exploit work in practice?
Given a finite group of integers, any group element Z in a group of order n, Z^n will always equal the identity element (order == number of elements in group). ECC has an equivalent abstraction - ...
- 906
7
votes
How does RingCT prevent doublespend ?
RingCT does not create fake outputs. Here is a good dumbed-down explanation of its principle: ELI5: How does RingCT work?
Therefore there is no difference between "normal" transactions and RingCT ...
- 594
4
votes
Monero double spends in the txpool
First one to get in a block wins, there can be no other way as far as I understand. I mean, who has the authority to say which one came first?
For this, we have PoW and the blockchain - to avoid ...
- 19.9k
4
votes
How does the recent patched key image exploit work in practice?
The above answer by Lee Clagett is also helpful for understanding how the exploit on Bytecoin took place, which is different and less effective than the exploit discovered by MRL. The attacker first ...
- 2,475
3
votes
Accepted
Calculating the cost of a double spending attack
It depends heavily on how much work has to be (provably) redone. If you act upon a transaction that has just hit the txpool, there is not work yet to be redone by a miner, so it's cheap. Same as for ...
- 34.9k
1
vote
Accepted
What prevents double-spending?
1st (1 Monero) + 3rd (100 Monero) = 4th_Mine (90 Monero) + range proof balancing (11 Monero)
2nd (1 Monero) + 3rd (100 Monero) = 5th_Mine (90 Monero) + range proof balancing (11 Monero)
Let's call ...
- 19.2k
1
vote
Accepted
Acquiring greater than 51% of the Monero network can pose what kind of risks?
As I understand it, if a mining operator was to attain 51% of the network, they can perform a double spend.
This is one thing they could do, yes.
But would this be detected?
You cannot detect a ...
- 19.2k
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