Security-wise, would it be a good or bad idea to use my Bitcoin private key as a NXT wallet passphrase?
Since it is impractical to brute force a Bitcoin private key, it should be safe enough to use as a NXT passphrase too, right?
I'm curious because if it works, then it would be one less thing to remember. The idea that the private key for an existing Bitcoin address can also act as the "key" for a NXT address is an attractive one.
And could this work for other coins too? Could I use a Bitcoin private key to unlock a Dogecoin address? Or a Namecoin address? Could I print a paper wallet with a private key that contains - in addition to bitcoins, a variety of different cryptocurrencies inside it as well?
EDIT: What about using Electrum seeds as NXT passphrases? They look pretty similar (i.e. 12 random words).
Well the only issue I can see is if you lose one wallet you lose them all. But I'm no expert.