Question about re-using old private kyes

Accordingly to the history-revision attack, an attacker acquires old private keys that have once controlled many coins, but that doesn’t any longer. But doesn’t that imply that these spent outputs have already had their coin days consumed on the main chain and therefor the attacker is competing “against his own coins”?

I mean if the attacker stake these coins, the stake will not be able to accumulate more then 60*nbrCoins and the spent coins could potentially have much more coin days consumed on the main chain. If the coins had basically no coin days, the attacker could accumulate a stake where these coins get more coin days on the attack chain, but during that time the main chain will also get more chain trust.

Right?

EDIT: If I get this right, it implies that the odds of pulling of an attack using old private keys gets even smaller which is good news.

I haven’t been able to convince anyone to sell me – or any of a number of sock puppet accounts – old keys from addresses that had more than 100k PPC in each. I guess that’s a good thing, too.

Yes my question is purely of academical interest. I want to better understand how Peercoin works.

is it possible to get old testnet keys that had more than 100k testPPC in them? (seems a bit easier to accomplish, instead of mainnet coins)

Hi, i’m an investor and i’m definitely interested in the peercoin project.
I’m very curious to understand how peercoin deals with the history attack issue, is that an issue for PPC ? ???

Welcome to the forum wise investor! You raise a serious question. Fortunately, there are lots of bright people here who have answers.

Check out:

There are also links at the bottom of that post that will direct you to even more in-depth discussion on this important topic.

[quote=“learnmore, post:6, topic:2674”]Welcome to the forum wise investor! You raise a serious question. Fortunately, there are lots of bright people here who have answers.

Check out:

There are also links at the bottom of that post that will direct you to even more in-depth discussion on this important topic.[/quote]

TY for your answer, do you know where i can find stats about number of coins used for minting in the past 2 years?

Have a look at these amazing charts maintained by mably.

https://www.google.com/fusiontables/DataSource?docid=1yFAWEkXqKXuKwwtCuh47lKuyw3HJAi3tPxlO3RgI#chartnew:id=5

The first tab contains all the raw data from Block #1 onward.

[quote=“learnmore, post:8, topic:2674”]Have a look at these amazing charts maintained by mably.

https://www.google.com/fusiontables/DataSource?docid=1yFAWEkXqKXuKwwtCuh47lKuyw3HJAi3tPxlO3RgI#chartnew:id=5

The first tab contains all the raw data from Block #1 onward.[/quote]

Thanks for the link I’ve just discovered the charts from mably, great work! I was looking for this kind of data too

[quote=“GLock, post:9, topic:2674”][quote=“learnmore, post:8, topic:2674”]Have a look at these amazing charts maintained by mably.

https://www.google.com/fusiontables/DataSource?docid=1yFAWEkXqKXuKwwtCuh47lKuyw3HJAi3tPxlO3RgI#chartnew:id=5

The first tab contains all the raw data from Block #1 onward.[/quote]

Thanks for the link I’ve just discovered the charts from mably, great work! I was looking for this kind of data too[/quote]

You’re welcome, happy to help :slight_smile:

Yes, the attacker is competing with the main chain. If the coins have been used for minting the whole time on the main chain, then the attacker only gets a negligible advantage (on his chain the coins were not spent so they have a little more age).

These coins may still help him to build an attack, but it needs other coins. Basically, he needs more than the average amount of coins minting since the start of the history revision.

[quote=“LeChatNoir, post:5, topic:2674”]Hi, i’m an investor and i’m definitely interested in the peercoin project.
I’m very curious to understand how peercoin deals with the history attack issue, is that an issue for PPC ? ???[/quote]

This thread could prove very useful to you:

In this thread I present all of the most common myths about Peercoin along with some arguments.

There are some prominent people spreading these myths about Peercoin that are quite active on social media. I’m not naming names, but I’ve actually had engaged in email conversations with may of them. So far not a single one of them have presented attackts/information that the Peercoin community isn’t already aware of.

Actually the most evil attack vectors that I’m aware of, have been presented by the community itself. Sunny knows about them. What are we doing about it? Different people are doing different things. There is Peerbox, cold minting and a pretty healthy discussion about these things in general.

If there is ONE thing that we could improve on, I think, it is to create a decentralized p2p exchange for PPC vs BTC/LTC/XXX. Fiat is less important here I think. But a pool with high liquidity, so that people who like to trade and want to do so in high volume, can do so without sending them coins to a centralized exchange. Just my 5 satoshis.

Ok ty everybody, pillow i’ve already read the thread with the debunked myths it was very useful.

I think it will not be the fairset distributed coin that will win the cryptocurrencies race. It will not be the most accepted, it will not be the oldest one and it will not be the coin with the most futures built in.
I’m sure it is the coin which provide the strongest network at the lowest cost to win the cryptocurrency race, that’s why i’m very interested in peercoin.

I define network strength as the ratio ($ bad actor has to spend to compromise the protocol) / ($ market capitalization of the coin).
Bitcoin’s network strength is actually very very low in my opinion, i think you can shut down the network by spending no more then 3/100 of the total market capitalization.
And after that we must consider all POW coins will become weaker and weaker with time because centralization of mining and decreasing block rewards will push down the ratio even more.

Now my question is, what’s the network strength ratio for peercoin and how do you think it will evolve over time? If you have to draw a chart of the ratio how would it be?

[quote=“LeChatNoir, post:13, topic:2674”]I define network strength as the ratio ($ bad actor has to spend to compromise the protocol) / ($ market capitalization of the coin).

Now my question is, what’s the network strength ratio for peercoin and how do you think it will evolve over time? If you have to draw a chart of the ratio how would it be?[/quote]

About 10% of peercoin are minting. Assuming the attacker is not already minting, he has to get 10% of all peercoins minting for him to do a 51% attack reliablly. After the attack, if the price peercoin drop to near zero, the attacker “spends” the amount of 10% peercoin’s market cap. There are other scenarios, e.g. the attacker buys less coin and could attack the network by pure chance. If the attacker spend 2.5% of peercoin market cap and starts attack today, he will have one chance every several months. It’s much more difficult than attacking bitcoin as you pointed out – 2.5% of bitcion marketcap can almost allow you to take the network over.

I guess peercoin now is 2-3 times more secure than bitcoin in that sense.

Once cold storage secure minting is implemented I expect more people will be willing to mint, making the attack even more difficult – the attacker will have to have more – up to 51% of all – peercoins. Distributed exchange will help, too, because a large sum of peercoins are sitting in btc-e’s cold wallet, not minting. For bitcoin as the block reward gets halved, more miners will be out of business, the network secure factor will be even lower.

How do you know 10% of peercoins are minting? Is that percentage improving over time?
Since network security is proportional to % of peercoins minting, wouldn’t be a good idea to increase PoS minting reward to 3% per year?

[quote=“LeChatNoir, post:15, topic:2674”]How do you know 10% of peercoins are minting? Is that percentage improving over time?
Since network security is proportional to % of peercoins minting, wouldn’t be a good idea to increase PoS minting reward to 3% per year?[/quote]

The evidence is in the link I gave.
See previous discussion such as Minting with capped maximum stake

To the exception of the non hashcash Primecoin - It has 2 anti-centralization features. 1) Brute force hashing random numbers, under rigid guidelines (the more CPU, the stronger) does not work - there’s no known guidelines to find prime chains
2) Elastic reward recalibration, in real time (reward gets immediately lower if difficulty would happen to rise)