Topic: Curious question regarding block confirmations (Read 484 times)

Indeed, blocks contain the hash of previous block, forming a linked list or chain, thus the blockchain. (tadaaaa !)

However the hash of a previous block can be contained by more than one candidate sibling at a given time, this is fairly common. This could be caused for example by two miners who solved a block almost at the same time and broadcasted their block, or by a double spend attempt. Since the network is distributed there is no way to know what is the "right" block.

The majority of the network picks a block they want to extend (for example, the block that does not contain what they ascertain to be a double spend) and they continue to extend that subchain. The algorithm is designed as to use the longest chain as the "main" chain, however it's fairly common that the majority of the network has a different view on which is the main chain. When this happens a reorganization takes place, and the miners who were working on extending the alternate subchain switch to the correct one.

https://en.bitcoin.it/wiki/Chain_Reorganization

The hash power used to create the orphan subchain is wasted and no coins are credited for it (technically there are, but you can spend them only in the orphan chain which nobody accepts). A fast block rate (such as in litecoin or feathercoin) favors block reorgs, and it's an open debate on what is the best security/speed tradeoff.

There is no possibility to have more chains because every block is based on the previews block. I don't know what it is or how is made, all that I know is that the current block contains the checksum of the previous block who in turn contains the checksum of the block before, or something like this. I'M NOT AN EXPERT so this is what I understood form reading on the internet all day.

I assume such a large confirmations requirement has to deal with the possibility of chain reorganizations. Unlike a double spend for a regular transaction, where 6 confirmations in one chain will usually guarantee the transaction will be found in all competing chains, for the coinbase transaction (new bitcoins mined) a chain fork and reorg will guarantee that the coins mined on the alternate chain will be worthless.

So it makes sense to expect a large number of confirmations before paying the mining shares. On the other hand, if the pool pays using the mined coins themselves, it should have no risk. So the real reasoning could be a bit more complex.

As far as I know, all it does is check how many blocks have passed on the entire network since the block was mined.

I mined before on 2 different pools, one bigger and the other smaller. Noticed a difference in speed of confirmations so thats why I was curious on who is doing the confirmations. Maybe there was a difference in site stats updates  . Anyhow thanks for the info Jaxkr.

I'm not exactly an expert, but I think I know how this works in Bitcoin at least. I assume Litecoin is the exact same, but with some different numbers.
The blocks are verified by the rest of the network. This is to ensure that an invalid block isn't used. Each block must agree with the previous blocks, and each block on top makes all the previous blocks more valid.

I've been mining for only slightly over a month and have been curious about block confirmations when a block is found.

For example pool mining LTC requires 120 confirmations before payment is credited. Is block confirmations done by the finder of the block or the combined pool miners or the entire LTC network?

Anyone experts care to enlighten?