Quote from: Abdussamad on March 03, 2015, 04:51:38 AM

You can do this with electrum 2.0 using the command line:

Code:

electrum --entropy= make_seed
electrum --entropy=3959389439878943984398743 make_seed

Please be careful if you use this feature. The entropy integer replaces some of the entropy which Electrum would normally use; if the entropy integer is long enough (39 digits for a 128 bit seed), it will replace almost all of the entropy which Electrum normally uses.

If your integer comes from a good source of entropy, then none of this is any concern. But if not, you're asking for trouble.

Quote from: zemario on March 02, 2015, 04:51:13 PM

My favorite way of creating keys is manually feeding a very long string of gebrish to a brain wallet tool.

If by gibberish you mean dice roles, a well-shuffled deck, or similar, I'd say that's a very good way to generate a wallet. If you mean "banging on the keyboard for a while", I'd be concerned. If you're going to go through all the effort to make your own entropy and store it cold, please take the extra step of using a real entropy source. Otherwise, your "banging on the keyboard" may end up making your wallet weaker than if you had just used the default OS-provided source of pseudo-entropy in the first place (as most wallets do, including Electrum).

If you're getting your entropy from a good source, you can do something like this do convert it to an integer for use with Electrum 2.x (at the command line; if you're on Windows, you need to download Python 3 first, and it's called python.exe instead of python3):

Code:

python3 -c "import hashlib;print(int.from_bytes(hashlib.sha256(input('entropy> ').encode()).digest()[:int(input('bits> '))//8],'big'))"

entropy> ks 3s 9c jc kh 3c td tc 4c 9h 4h 7c 2c 6d ac 9d qc 3h as ts 8s 5d ad 2h 5s
bits> 128

183982767129046887860016900583690846407

In that case, I used a well-shuffled deck. You only really need the first 25 cards, but a few more wouldn't hurt. I entered "128" for the estimate of bits, this number should be somewhere between 8 and the seed length in bits, usually 128. If you're using a well-shuffled deck, entering 128 is fine, but if you're using something else and if you overestimate how much entropy you've got, you'll end up decreasing the security of your wallet (because of what I described above), so just be careful

. For 6-sided dice, you'd need 50 rolls for 128 bits. For 20-sided, 30 rolls. If you're feeling lazy, you can decrease this, but you must decrease the bit count proportionally (and then Electrum will fill in the rest from the OS's pseudo-entropy).