475 sats \ 3 replies \ @freetx 1 Feb \ on: Mercury layer AMA bitcoin
I've read thru the website and although much of the math / crypto goes over my head, I understand the principle of it and appreciate it.
A few questions:
  • It sounds like LN with regard to clients needing to be online? Or am I mistaken?
  • Also, is it correct to say that clients must ensure that they keep backup of transaction states?
  • What happens if the SE goes completely offline (all servers destroyed for example)?
  • Lastly I'm a little unclear of who would be running the SE? Is this a federation? How would we know about federation membership? etc?
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172 sats \ 2 replies \ @tptrevethan OP 1 Feb
  1. No - you don't need to be online - either for chain-watching or receiving. Transfers happen in a two steps operation: send and receive. But receive can be done at any time - don't have to be online at the same time.
The backup transactions have an absolute timelock - so there is no way a previous owner can broadcast before the timelock. If the operator is shut down, the owner needs to be online when the timelock becomes valid.
  1. Yes. However the operator keeps and encrypted transfer message (which is just an encrypted blob to them) which can be used to recover the wallet if all you have is the seed. Obviously if the operator is shut down, you need the backup data.
  2. In case operator shut down, all owners need to wait for the timelock expiry, and make sure their backup is confirmed in the time window (using CPFP if necessary to bump the fee - wallets can be configured to do this automatically).
  3. We (Commerceblock - a UK company since 2017) will run a mainnet server - as a single entity. Obviously trust is required - which can grow over time as reputation increases from reliability. Anyone else can run their own. Federation is possible - current implementation would need to be extended.
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150 sats \ 1 reply \ @freetx 1 Feb
Thanks for the reply:
So appox how many blocks is the timelock?
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124 sats \ 0 replies \ @tptrevethan OP 1 Feb
It is up to the user (the server can't enforce or see) but clients will use a default value.
For a long lifetime coin, this should be months.
For the DIFFERENCE on transfer:
It needs to be long enough to get the backup confirmed in that time. Assuming a CPFP to bump fees to the required fast confirmation level, this can be a short as a few hours.
However this becomes less secure for low value coins (where fees might be high in the future).
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