Bitcoin Forum

Electrum Seed Guardian - Never lose your bitcoins

Website: http://seedguardian.github.io/ (http://seedguardian.github.io/)
Github repository: https://github.com/seedguardian/seedguardian.github.io (https://github.com/seedguardian/seedguardian.github.io)

Electrum Seed Guardian aims at keeping your electrum seed safe and secure. It splits your electrum seed in shares of 15 words, using Shamir's Secret Sharing Scheme.

Split of a secret is powerful, as it avoids the lose of your secret. If shares are correctly hidden and geographically distributed, risks like fire, theft, loss are a lot reduced.

Shares made of words rather than hexadecimal allows you to write them down manually without errors. You coould make a shared paper wallet without any printer, this is good if you can't (or don't want) to trust your printer.

This software is just new, so use it at your own risk.

You are welcome to report issues here or on github.

Do I need to save my seed on paper and use that wallet forever without worrying about doing any other backups?

Electrum seed is sufficient to recreate your wallet. So you could use electrum to generate a seed, write it down somewhere and you have your cold wallet. But there are risks with this method. You could lose the paper with the seed, or it could burn, or someone could use it if the paper is found.

That's why i created seed guardian. You split electrum seed, let's say in 3 shares with a threshold of 2. You write down the 15 words of each share on a different paper, and hide each paper in a different place. For example, one on an encrypted usb drive, one with your papers at home, one at work. If one of these papers is lost or burnt or stolen, you still could recreate the seed with the two others. If someone find one of the three papers, he can't do anything with it.

this is very cool.  I will use it.

Nice. Don't forget to keep a copy of the software (you could get it from github here : https://github.com/seedguardian/seedguardian.github.io (https://github.com/seedguardian/seedguardian.github.io)) and to use it offline.

RagnarDanneskjold found a bug :
When threshold is not equals to 2, the seed is not reconstructed correctly.

Avoid using this software for anything but test.

Bug is fixed.

I would like to thank the anonymous donator.

https://blockchain.info/fr/tx/7ffbd2c7fd6951f227f8f10b5b4f40497bb84b5454ca2748a53200d76823bf7d (https://blockchain.info/fr/tx/7ffbd2c7fd6951f227f8f10b5b4f40497bb84b5454ca2748a53200d76823bf7d)

This is a wonderful tool :)

Thank you so much for sharing it with the community!

Will donate $5 in just a minute.

Madmat,
Trying to use it right now. It won't let me supply an existing seed.

What PRAND source are you using to generate these seeds, and how many bits of entropy does it use?

Why can't I supply my own seed that electrum generates?

At first, thank you for the donation.

If there is a bug, I will fix it tomorrow, I only have a phone with me today. Please do an exact description of the steps leading to the problem, so I could easily reproduce it.

Seedgiardian uses the random source provided by secrets.js, and it is 128bits, as spectrum does.

I reproduced the bug on my phone. I don't need more information to fix it. I am going to debug tomorrow.

Awesome. Thank you!

Bug fixed. You could see the diff here : https://github.com/seedguardian/seedguardian.github.io/commit/54e3dcb97d810c0b2e2601916ba05e322baaad76 (https://github.com/seedguardian/seedguardian.github.io/commit/54e3dcb97d810c0b2e2601916ba05e322baaad76)

Thanks!!

You are welcome.

If you find other bugs, you could report them here : https://github.com/seedguardian/seedguardian.github.io/issues

This is really cool.

How does everyone distribute the new seed parts? Do you write them down and hide them in difference places? Or encrypt them and put them on different cloud storage servers or something?

You have different options.
First, to avoid fire risks or thief risk, you must hide them in different places. you could hide one in your house, one in your parent's house and one at work, with a threshold of two.

If you want, you could write it down on a paper and hide the paper, but you could also hide them in a book, just by adding a dot near the 15 words in the text of the book, in the order you find them. You could make a qrcode with the 15 words, print it on a sticker and stick it to the back of a book or something else, noone will notice it, even if it not hidden.

You could write an email with the 15 words hidden in white on white and send this email to yourself. Make sure you use double authentication for your mail.

Your imagination is your friend.

I have plans to add functionalities :
1. get the first address of the electrum wallet without the need of electrum
2. paperwallet, with one share and its qrcode, and first address and its qrcode

I need time to do that, and i won't have any during august. Maybe september.

Awesome, thanks!

Those are some really good ideas too.

I also found: http://passguardian.com/

Some ideas:
Support of BIP39 and/or the possibility to use 128-256 bit mnemonics.
Displaying the shares as mnemonic / qrcode / hex

Maybe i'll fork and will try it by myself. AngularJS is just great to play with :)

Passguardian is great. I use it for bip38 passphrase.

I am going to read bip39, as i don't know it.

If you fork the code, don't hesitate to do some pull requests, any help is welcome.

So basically you are protecting your private keys with BIP 38 passwords + use passguardian to split the keys. Isn't this kind of an overkill?

yea thats more good than save internet if thats about milliion bucks in bitcoin .
prepare more good than speculation.

I don't do that. i split the bip38 password with passguardian, not the key.

Ahh, that makes perfectly good sence. Might want to implement this myself! Thank your for the idea.

Everyone here could help this little project by doing following things:

  1. Test it and use it  http://seedguardian.github.io/ (http://seedguardian.github.io/)
  2. Report bugs  https://github.com/seedguardian/seedguardian.github.io/issues (https://github.com/seedguardian/seedguardian.github.io/issues)
  3. Develop it, by forking it and do some pull requests  https://github.com/seedguardian/seedguardian.github.io (https://github.com/seedguardian/seedguardian.github.io)
  4. Give bitcoins: 15zvrQeY3jPmqQGUPYZBRVfmfBy5Deo7FA

You don't need to use bip39 to convert the hex shares into mnemonics. Electrums own mnemonic.py  file (in lib/) can do just that:


The functions are mn_encode() and mn_decode().

seedguardian uses mnemonic.js which is a reimplementation of mnemonic.py.

https://github.com/seedguardian/seedguardian.github.io/blob/master/lib/js/mnemonic.js (https://github.com/seedguardian/seedguardian.github.io/blob/master/lib/js/mnemonic.js)

Good to know :).