Current Proof of Stake Difficulty

[crypto_coiner]

I don’t have a quantitative idea of Nu’s security, though I know qualitatively, it is (much) higher than a system like, say Bitcoin

[cryptog]

0.000263 now.

[mhps]

The difficulty went up a little when there were several votings for things other than the usual liquidity pool grants. Some motions had unusually high share days such as

[Passed] Reduce the total displayed supply of NSR by 10,000

Hi @tomjoad Here are the details for the Motion Vote on e0b3f80e5d9f58d3c3df27e346b61233b9cd5153: e0b3f80e5d9f58d3c3df27e346b61233b9cd5153 Blocks: 5004 (50.040000%) Share Days: 1810040176 (54.118211%)

suggesting that some big amount of shares came out from sleeping to vote. [edit to note: Not necessarily specifically for the motion in the example. it’s possible that all motions in this period had greater share days % than blocks %, if the holder(s) of aged shares felt s/he might as well vote for all motions s/he supports when not sleeping.]

Now the difficulty is taking a nose dive to 0.00025266. My shares are finding record breaking number of POS blocks. Is it because those voting shares go back to sleep again? Huge amount of shares stop minting and go to exchanges before buy back?

[crypto_coiner]

Huge amount of shares stop minting and go to exchanges before buy back?

Do you suggest that these nushareholders aim at selling high for that buy back and buying back low later?

[mhps]

Selling (of course) for a better price.

[mhps]

By my estimate there are ~210 million shares minting.

When a chunk of 10k shares finds a new POS block, the chunk will not be allowed to find a new block in 5020 new POS blocks. It takes some other chunk’s finding a new block to advance this chunk’s position in the queue of 5020 by 1. This means that if there are less than 50.2 million shares (5020 chunks) minting, the Nu network will get stuck.

Wow. We are just 4 times above the critical point.

[crypto_coiner]

Can the “5020” size be changed by motion?

[mhps]

Can the “5020” size be changed by motion?

It can. Changing it would be a hard fork. Peercoin also has this issue but it is not as critical as there isn’t the minimum minting amount requirement or chunking. Theoretically one Peercoin user can generate 520 utxos and keep the network away from this problem (but s/he has to put the 520 utxos in place before the blockchain is stuck!). For Nu if one user wants to do this s/he has to control 50.2 million shares.

[cryptog]

0.000267 now.

[masterOfDisaster]

When a chunk of 10k shares finds a new POS block, the chunk will not be allowed to find a new block in 5020 new POS blocks.

Why? Is this another limit in addition to the minimum age of UTXOs that is required to find a block?

My understanding is (was?) that the probability for an UTXO to find a block depends only depends on the difficulty and requires the minimum age of the UTXO to be reached.

[Nagalim]

The minimum age as written in the source code is a time: 72460*60 seconds. This is despite a block being found or not. That means if you are the only one minting with only 10,000 nsr, you will mint once a week and push 1 block forward each week.

The critical number @mhps is referring to (which I actually think is 10080*10,000 = 100.8 million nsr) is the minimum number to have real competition for each block and to keep blocks being minted on a minute by minute basis. The network will not get stuck, but there is still danger there none the less.

[mhps]

@mhps
When a chunk of 10k shares finds a new POS block, the chunk will not be allowed to find a new block in 5020 new POS blocks.

Why? Is this another limit in addition to the minimum age of UTXOs that is required to find a block?

I made a mistake. When a new POS block is found, the new block cannot move before 5020 more blocks are found. This is a security feature inheritated from Peercoin (520 blocks “stake time”). What matters here is that it will take 7 days (the minimum age) before the new block can mint again in Nu. Assuming 1440 new blocks are found every day, it means that the “waiting queue” is 1440x7 = 10080 blocks long, instead of 5020.

We are only two times above the critical point. Hope this is not becoming a trend.

[Nagalim]

the new block cannot move before 5020 more blocks are found

That’s not true. It’s a time thing.
https://bitbucket.org/JordanLeePeershares/nubit/src/6fe88883f316b1ff3448d52438e9d122f808da51/src/main.h?at=master&fileviewer=file-view-default
Line 52

[mhps]

Line 52

For the quoted number you should look at line 48. I think. (why do I remember it is 5020?)

Line 52 is for the 7 day.

[Nagalim]

Yah, that. I may be wrong, actually, and that may just be a target while the actual mechanism is by block. Either way, you’re very right that there’s a critical number of minting shares (100.8 million) and we need to stay well above it.

[mhps]

10.8 million

100.8 million.

we need to stay well above it.

Right.

[cryptog]

Difficulty (PoS) 0.000282 rising.

[cryptog]

Difficulty 0.00028523

By the way the minting difficulty of B&C is 0.00077437.

Does it imply that there is more voting at B&C?

[Nagalim]

not voting, but minting. Note that this can also be indicative of poor distribution.

[cryptog]

minting.

right

poor distribution.

Well I speculate that Nu’s distribution was similar to B&C over the first 3 months after release.
And yet minting difficulty of Nu was rather constant at 0.0002 level but minting difficulty of B&C went up gradually from 0.0002 to 0.0007, according to block explorers:

• https://blockexplorer.nu/charts/posdiff
• https://bcblockexplorer.com/charts/diff

So the distribution would not be the reason to explain the difference in my reasoning.