I agree completely.

The timeline and story that was told indeed made no sense and was almost certainly made up. The real story is unknown. We can only infer small bits and pieces from what is visible.

XDN had one-month halving, this has six months, but six months is still not very long. The coin has been out a month and a half and not much has happened. In another 3.5 months unless something changes half the lifetime supply will be sitting in a few miner wallets.

I'll disagree a bit. The original question asked "was there ever" and before the scam it is possible there was a glorious vision. The technology was developed by someone or some group who were highly capable, and probably that was done for more than scamming. It seems to have been coopted at some point.

This may happen but a lot of miners are just on autopilot and won't stop. The hash rate will never literally go to zero. People mine on broken abandoned forks for months if not years. So maybe the 200 minutes becomes 500 or 1000 or whatever. It doesn't really matter because the longer the spiked block times, the faster the difficulty will drop once it starts dropping.

You earlier mentioned that the attacker can keep driving the difficulty up, and this is true, but it changes it from a one time attack to an ongoing attack. If you're going to do that, probably a regular 51% is at least as effective.

The in-progress Surae Noether difficulty algorithm (its somewhere on github) might also be more resistant to these types of attacks. It is designed to resist changes in hash rate that are "unnatural". I haven't looked carefully at this particular scenario though.

I know of one other way to improve resistance against this attack.

We'll probably revisit it with ringct, which changes somewhat how fees work. Making these sorts of changes every time the market fluctuates up or down does not make sense.

If you are talking about me, I haven't even been online for most of the past day. I dropped in and posted a few times. Nothing to do with anyone else. Many of the other posts I'm not even reading.

That's harder to predict. As the price reaches new highs more people who previous didn't care are motivated to dig. If this is a diverse group of people then a slow rise would likely lead to steady digging. But there can be potential "big digs" where one person makes a decision to empty a huge wallet or a set of wallets. There is no way to know when any particular person might be motivated.

The other thing that happens is the supply naturally increases over time due to staking. So the later a dig occurs, the smaller it is in relative terms. In effect there is already a slow expiration of digging built into the current rules.

Huh? Secure against ordinary 51% attacks and against 1000x attacks are two different things. 51% is possible. It isn't cheap or easy, but possible for someone with significant resources.

Monero's hash rate is probably >1/1000 of Bitcoin when adjusted to equivalent energy. It is quite secure against 1000x attacks, especially considering they are not entirely effective as they were against some gen 1 alts. Algorithmically it is reasonably secure against 100x difficulty spike attacks (as are most other current alts such as Dash), though somewhat better than those that don't have a variable blocksize (again such as Dash) to absorb a transaction backlog.

For old wallets yes. Newer wallets use that by default.

Correct

Yup, I said this earlier (at the time the context was hypothetical counterattacks)

It enormous quantities it is. I did some estimates here: https://bitcointalk.org/index.php?topic=1520691.msg15312985#msg15312985

'NotBack you are going of the deep end a bit here.

The difficulty stratosphere attack you've described doesn't work very well against Monero if you work out actual numbers.

If you wanted to drive up the difficulty 1000x then you would need something approaching a billion typical (old, insecure, low powered) botnet nodes. If you wanted to use higher performance computers say from cloud computing you'd need 10 million or so, which is good portion of the capacity of the big cloud computing vendors. To rent that you would have to displace most or all of their other paying customers (or in the case of vendors such as Amazon or Google, their own usage). That won't happen.

Now lets say you did manage to, somehow, drive the difficulty up 1000x. You would drive the average block time from 2 minutes to 2000 minutes which is around a day and a half. The chain would not completely stall, it would continue to generate blocks at this slow rate. Those blocks would feed into the difficulty adjustment and after a few days the block time would rapidly begin to come down. It would still be slow for quite a while, but the severity would subside. Meanwhile, the blocks would be full of high-paying transactions and the block size would increase. The network would hobble along until it self-healed.

If you tried the possibly more plausible 100x version instead of the ridiculous 1000x version, then the block time only goes to 200 minutes, which hardly slower than Bitcoin on a bad day (I've personally waited over an hour for a block). Again, block size adjustment would start to kick in and clear the transaction backlog. Over time (hours to days, not years) the block time would start to come back down pretty fast anyway.

This ignores that Monero with a billion market cap would probably have a much higher baseline hash rate, meaning not only is 1000x implausible but 100x would probably be as well. And a 10x difficulty attack is just purely money for basically no purpose.

Nothing about this is specific to Monero's algorithm, which probably isn't even all that good. This sort of attack won't work against any current alts with faster base block times and difficulty adjustment algorithms that have been battle-tested not only by malicious parties but by auto-switching pools which do this form of "attack" automatically and routinely by rapidly moving massive amounts of hash rate between coins.

The attack works much better against Bitcoin-style coins (1st gen alts mostly) that start with a higher block time and that maintain a fixed difficulty for a (reasonably long) cycle. You drive up the difficulty during one cycle and the difficulty never adjusts at all until the end of the next cycle so there is an unacceptable wait for the whole cycle (2016 blocks in the case of many early alts that just copied Bitcoin).

Try here: https://bitcointalk.org/index.php?topic=653467.0

Under two bucks has a nice ring to it.

My opinion is that digging is largely predictable. Digging will increase when the price reaches new highs, as people who know they have CLAMs to dig but never bothered are motivated into action and the attention from the price increase informs more people about the CLAMs they didn't know they had, then level off.

The last "big dig" was after the large price increase. I predicted at the time that there would be relatively little digging after that digger finished unless the price recovered and once again began to make new highs.

This has not be tested statistically and probably can't be because the data set is too small.

I already explained that the expected value of the next hash attempt is lower if M is higher and if payouts are divided equally* between all accepted shares a depth N (M, a variable). This should be obvious given that the block reward is (approximately, ignoring tx fees) a constant and M is not, but apparently it is not obvious.

If I have misstated something in the above paragraph please let me know because it is still possible I misunderstand your proposal.

* assuming constant difficulty.

Agree with your assessment. Disappointing to see the hardware problems. If I had bought into batch 1 (glad I didn't, but seriously considered it) I would be putting any more purchases on hold until the problems are worked out.

FTFY