3 ms·

Possible the thought is that in a country where online transactions are not well monitored, it might take a while to be traced down. Personally, I don't unders

Possible the thought is that in a country where online transactions are not well monitored, it might take a while to be traced down. Personally, I don't understand how one time use money cards would have any preventions to prevent the same thing from happening. One could send someone to buy a stack of them with a wad of cash, and the original store the cards are delivered to might be tracked, but after that, what else is there? The money gets transferred out, and they might not even know what the purchase was. There are more private cryptocurrencies, but it's near mathematically provable that all with sufficient transaction history and brute forcing capability are traceable. In the case of law enforcement, all they have to do is sit in these transactions until the have the CPU power to break them. I'd had to be the one that used cryptocurrency to buy something illegal knowing that 50 copies of the ledger exist on other people's computers.

nostrademons 7y ago
Note that brute-forcing an exponential-time algorithm is not generally possible. If you have an algorithm with a runtime of 10^N, then after N=61 the runtime of the algorithm will be greater than the age of the universe expressed in the Planck Time. For a 2^N algorithm it'd take about N=202. If you're willing to talk in nanoseconds instead of Planck Times (chosen because our current understanding of physics breaks down at that scale), it's more like N=26 for the 10^N case. Practically speaking, though, users of privacy coins are usually looking for plausible deniability rather than total untraceability. The legal standard for criminal cases is "beyond a reasonable doubt"; if there's even a 50% chance that you're just an innocent person caught up by circumstances, you'll have trouble convincing a jury of guilt.
- not_a_cop75 7y ago
  I like your thinking, but all of this is assuming that runtime for something stays precisely the same no matter what. Most operations are at least reasonably parallelizable, and I would argue that cryptocurrency depends largely parallel operations, which in general should mean that breaking it is also a parallel operation. Plus with advances in quantum computing, regular computing and storage, it's hard to be sure how long any of this information will be stored for or long long someone would crack it for, or wait for it to be crackable. Also, you imply that some amazing computational shortcuts aren't ever going to be arrived at. This historically, is hard to be sure of. Not saying everything will be broken, but more of it is all the time.

nostrademons 7y ago

Note that brute-forcing an exponential-time algorithm is not generally possible. If you have an algorithm with a runtime of 10^N, then after N=61 the runtime of the algorithm will be greater than the age of the universe expressed in the Planck Time. For a 2^N algorithm it'd take about N=202. If you're willing to talk in nanoseconds instead of Planck Times (chosen because our current understanding of physics breaks down at that scale), it's more like N=26 for the 10^N case. Practically speaking, though, users of privacy coins are usually looking for plausible deniability rather than total untraceability. The legal standard for criminal cases is "beyond a reasonable doubt"; if there's even a 50% chance that you're just an innocent person caught up by circumstances, you'll have trouble convincing a jury of guilt.

not_a_cop75 7y ago
I like your thinking, but all of this is assuming that runtime for something stays precisely the same no matter what. Most operations are at least reasonably parallelizable, and I would argue that cryptocurrency depends largely parallel operations, which in general should mean that breaking it is also a parallel operation. Plus with advances in quantum computing, regular computing and storage, it's hard to be sure how long any of this information will be stored for or long long someone would crack it for, or wait for it to be crackable. Also, you imply that some amazing computational shortcuts aren't ever going to be arrived at. This historically, is hard to be sure of. Not saying everything will be broken, but more of it is all the time.