[feature Request] import existing private keys instead of sending BTC to eclair

[renepickhardt]

Some guy making a parody of my Lightning Network myth debunking video (in which I mentioned eclair as a wallet with a good user experience) actually talks about real user experience issue with Eclair mobile wallet in his video https://www.youtube.com/watch?v=3sNEx2VHKSs (around minute 5)

He describes the process to send BTC via the lightning network on eclair like this

install wallet --> Send on chain btc to that wallet (wait for 3 confirmations) --> connect node / open channel --> wait another 3 confirmations --> Send bitcoin over lightning.

My suggestion: if eclair would allow to import private keys one would not only have to wait less in order for the BTC to be transfered to eclair but we would also save an unnecessary onchain transaction.

the process would then look like:

install wallt --> import private keys (no waiting needed) 
--> connect node / open channel --> wait confirmation
 --> send bitcoin over lightning

this would effectively reduce the starting process by 50% of time.

Not sure if this issue should be posted here and not in the general eclair repo or even as a suggestion to the lightning-dev list. Well I start small (:

[sstone]

Importing private keys is imho useful only as a last resort (like when your old wallet won't work any more and all you can do is export private keys and import them in another wallet). It makes backup/restore much more complex and error-prone and can have unwanted side-effects (you import a non-segwit UTXO then you have a potential malleability issue, ...). AFAIK most wallets recommend that you don't import old private keys but swipe them instead (i.e. spend them and send the funds to your wallet).

Also, eclair-mobile follows BIP49 so if you restore a BIP49 seed from another wallet you'll be able to use it right away.