I’m not sure payment channels are really necessary for normal commerce like checking out at a convenience store. How long does it take for 0 confirmation or 1 confirmation?
Needless to say, slower transactions are fine for venmo type transactions. As long as the user doesn’t have to keep their screen open the whole time it’s doing its thing.
Grin has the lowest risk of loss of funds from all crypto I know because it is interactive. If you safely store your backup seed and use a properly secure password, there is less chance to lose funds compared to Venmo or any banking App. Banks can fall, Grin can only fall if some major mistake is made, like with the inflation bug. The chance of that ever happening again is very small.
Only downside is the need for grin to unlock your wallet to receive. Using a hardware wallet makes grin much more safe. I wish we had an oficially suported HW wallet
MimbleWimble is one single transaction, we can exchange outputs, like mwixnet did for fast txs maybe, privacy is must have for Grin, at usual blockchain POW is in the last place..
Then channels should be perfect solution for fast txs while we have no DAG or Blockchain with 1sec blocks, seems like cause memory is not fast enough yet.
Lightning is a bit riskier. Transaction channels work like a 2/2 multisig with both users having a revokation key. Quite similar to Grin on chain transaction, but in grin when both parties have signed and the transaction is broadcasted and appears online, its final. The difference with Grin is that the transaction directly appears on chain, making it final. In lightening, only when a channel is closed, all transactions are truly finalized and all parties receve their share on-chain. In the mean time, disputes can occur. Attacks are possible and your wallet (or watch towers) need to stay vigilant and setle any disputes within the dispute setlement time (normally 24 hours). Lets say someone does a DOS attack on your lightning node bringing it offline, funds in your channel can be stolen by the other party broadcasting an old state.
Also, if you lose your lightning node, regaining access to opened channels is hard. If you restore your wallet from seed, you do not automatically see opened channels. Lightning is therefore much more complex than Grin on chain transaction because your wallet has to mitigate all the potential attacks. Also there are privacy concerns with lightening, options to block or sensor transactions, centralization concerns etc. Hopefully all these challenges will be solved over time.
In this case, Grin is honestly just slightly better than Venmo because it offers privacy.
The slower speed is negligible when just sending money to friends because it can happen asynch.
There’s a slight UX annoyance compared to Venmo because of the round robin stuff that needs to happen to finalize transactions, but that can be turned into a benefit with a good UI (swipe to finalize / accept with a fun animation)
