Reserve balance

jubalix · January 31, 2014, 9:30pm

if i am minting, and use a reserve balance

how is the reserve balance chosen, from what addresses…does it matter?

what happens in I change reserve balance during minting

(a) up

(b) down

I imagine I should turn minting off before changing reserve balance

sigmike · February 1, 2014, 9:03am

[quote=“jubalix, post:1, topic:2011”]if i am minting, and use a serve balance

how is the reserve balance chosen, from what addresses…does it matter?[/quote]

The code is here and here.

Here’s how I understand the algorithm (in the situation you describe):

all your received transactions are shuffled
only valid transactions are kept (not spent, etc.)
if a transaction amount matches the requested amount (i.e. balance - reserve), it’s used
it tries 1000 random sets of transactions and selects the closest to the requested amount
if you have any single transaction whose amount is closer than this set, use it
else use the set

So it tries to find a set of transactions whose sum is the closest to your balance minus the reserve. This process may involve randomness.

[quote=“jubalix, post:1, topic:2011”]what happens in I change reserve balance during minting

(a) up
(b) down

I imagine I should turn minting off before changing reserve balance[/quote]

If you change it using RPC, it’s stored immediatly and used the next time the algorithm above is run (about 0.5s later if minting is enabled). If you change it in the config file I think you must restart it.

jubalix · February 1, 2014, 10:21am

thanks!!!

sigmike · February 1, 2014, 11:59am

I think it may matter because the coin age is ignored during this selection. For example if you have a transaction output that equals the requested coins, it will always be used even if it doesn’t have enough coin age. It will be dismissed only later during PoS check. If you have other transactions with enough coin age they won’t be used at all.

But I guess this is a rare case where the consequences are not tragic (you miss some chances to find a PoS, but you still accumulate coin age and do not reduce the reward you’ll eventually get). It’s solvable but probably not worth the work right now.

The code says you can use a -printselectcoin debug flag to log the selected set.

NewMoneyEra · February 2, 2014, 4:45am

[quote=“sigmike, post:2, topic:2011”]The code is here and here.

Here’s how I understand the algorithm (in the situation you describe):

all your received transactions are shuffled
only valid transactions are kept (not spent, etc.)
if a transaction amount matches the requested amount (i.e. balance - reserve), it’s used
it tries 1000 random sets of transactions and selects the closest to the requested amount
if you have any single transaction whose amount is closer than this set, use it
else use the set

So it tries to find a set of transactions whose sum is the closest to your balance minus the reserve. This process may involve randomness.[/quote]

Thank You very much Sigmike!

I really appreciate you reducing some of these processes in the code to English language logic.

This type of effort from you really helps me understand better.

Please do more like this on any aspect of PoS minting whenever you get the desire.

I applaud you. And, if you will post a Public Address I will send you a PPC donation.

Because, unfortunately, I am not a coder here is something I am reduced to just wonder about:
Paper Wallet Proof-of-Stake minting?
Could software be designed to be a PoS-minting Watch-only wallet? That is could a wallet possibly have a PPC Public Address but not have the Private Key and still participate in PoS minting? Perhaps if the Private Key has signed to allow minting?

sigmike · February 5, 2014, 6:48am

[quote=“NewMoneyEra, post:5, topic:2011”]I really appreciate you reducing some of these processes in the code to English language logic.

This type of effort from you really helps me understand better.

Please do more like this on any aspect of PoS minting whenever you get the desire.[/quote]

I will try. I’m considering drawing schematics of some of the internal processes of peercoin (for example in Drakon). I think this kind of schematics are understandable by everyone if the steps are in plain english with the least possible technical terms. But I’m not sure I’ll have time for that. I may at least write a technical FAQ.

Thank you. I put an address in my signature.

[quote=“NewMoneyEra, post:5, topic:2011”]Because, unfortunately, I am not a coder here is something I am reduced to just wonder about:
Paper Wallet Proof-of-Stake minting?
Could software be designed to be a PoS-minting Watch-only wallet? That is could a wallet possibly have a PPC Public Address but not have the Private Key and still participate in PoS minting? Perhaps if the Private Key has signed to allow minting?[/quote]

I think Sunny King is already planning a solution but I don’t know if he mentioned how or when.

For the network to be secure, you need to prove you own aged coins to generate a PoS block (otherwise anyone could easily destroy the network by generating as many blocks as they want). Right now the only way to prove that you own them is by signing a transaction with the private key of your coins.

But the bitcoin system is very flexible so we can quite easily change the protocol to allow special transaction (that was done to allow multisig for example).

Most of the transactions are simple “pay to address”. That means they have a script attached that says “you can do whatever you want with these coins if you can sign with the private key of address X.”
On multisig transactions, the script says (for example) “you can do whatever you want if you can sign with 2 private keys of addresses X, Y and Z.”

In our case we could allow transactions with a script that says “you can generate a PoS block if you can sign with the private key of address X, and whatever you want if you can sign with the private key of address Y.”
This way you could have a private key that can only be used as PoS. You could keep it unlocked without too much risk.

We would have to force the output to be the same as the input in this PoS block (which is not the case right now: you can change your client to make it move your coin when it finds a PoS block).

I don’t know if there already are such transactions in bitcoin where a signature is only valid in a specific context. I think it should work. It’d probably require a new script “word” (something like “are we doing PoS?”).

It would also help on the issue mentioned above where you don’t know which coins are really used for minting.

Building a good user interface for that may take some time.

I think that’s one possible solution. There are certainly others.

Anyway I think we can’t implement a solution only on the client side because when you received your coin it was explicitly said that only your private key can use them and the protocol obeys that even during PoS. We need to change the protocol (i.e. all clients).

NewMoneyEra · February 7, 2014, 6:53am

[quote=“sigmike, post:6, topic:2011”][quote=“NewMoneyEra, post:5, topic:2011”]I really appreciate you reducing some of these processes in the code to English language logic.