So, say i find 3 confirmations acceptably safe. That's exactly 3 confirmations in litecoin too for the same safety?
That's 30 minutes vs 6 minutes (it was 2min/block iirc)... on average.
Yes. (It's 2.5 min so 7.5 min).
Why are we still using bitcoin instead of litecoin again? because it's most accepted?
1. Yes, because it's more accepted. If we switched to a new currency every year because of some alleged trivial benefit, we would miss the point.
2. Decreasing the average block time has the obvious benefit of reducing time for confirmations. But it has equally obvious disadvantages:
a. There is more forking, meaning an attacker has more effective hashrate. I've ignored inadvertent forking completely in the paper, but it starts being a problem if we go wild with reducing the time constant.
b. There are more blocks, and hence more block headers. For a full node this is negligible but for an SPV (aka lightweight) client this makes a world of difference, especially if it is to be run on weak mobile devices.
So some tradeoff needs to be chosen. It can be argued that 2.5 min is better than 10 min, but it's far from clear-cut.
3. It doesn't really matter ultimately. If you can afford to wait more than a few seconds, you can usually afford to wait an hour. If not, I believe the gap can be bridged with
Trustless, instant, off-the-chain Bitcoin payments.
4. Because Litecoin might be more prone to botnets.
You could arrange bitcoin so that you had to submit n different PoW hashes in each block; each of which met a difficulty target (about n-fold lower than the current one).
Interesting, need to think about this.
DAG stands for Directed Acyclic Graph. The PoS article you linked to mentions this once, not going into detail. I think it refers to the structure of the block relations. The blockchain currently forms a tree, where different branches are not reconcilable, with one having to be eventually forfeighted. I guess the proposal is to make it possible for branches to join back. I don't know of any such proposals though.
Thanks. It's probably the blocktree thing then.
This is indeed what a DAG is and I think we're thinking about the same proposal. I might try linking to it sometime.
