Bitcoin Forum

Everybody, i have a BIG question.

Is there any multi-owner wallets? Something like a wallet that more users can acces using different ID's, And if someone makes a tranzaction, everybody else must approve it first.

Thank you for writing an answer. It helps me a lot.

I will give someone a little bit of BTC if the answer he gives to me is perfect (he offers me a service name and explains about it), if needed, If you want that, write the address or Coinbase e-mail.

Use a multisig wallet.

Armory and Electrum would be best choice.

Edit: Sorted according to my likes.

• Armory (https://bitcoinarmory.com/)
• Coinb.in (https://coinb.in/#newMultiSig)
• Electrum (https://electrum.org/#home)
• mSIGNA (https://ciphrex.com/products/)
• Copay (https://copay.io/)
• Coinkite (http://blog.coinkite.com/post/102291566521/bitcoin-multisig)

Ok, how does it work? I mean, tell me one that is easy to use, secure, and tell me how to create one. I will look up for multisig so I can see what it is.

I am very poor at explanation. If you want to get a better(/best) answer, it is good to wait for DannyHamilton's post but I am not sure he will post here. ::)

Multisig addresses needs m-of-n signatures when sending a transaction. Here n refers to maximum number of signatures you need and m refers to minimum number of signatures you need to send a transaction successfully.

Let's say, there are 5 people in your office and you want at-least 4 of them to approve a transaction. Then, you create a 4-of-5 multisig address. If you want to spend an amount from that wallet, minimum of 4 staffs need to approve it, so if only 3 staffs approved it, the funds won't be moved.

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"Easy" differs from person to person. If you have a good internet connection and good storage - min. 60+ GB((which I assume you have), then Armory is best choice. If you want to go for lighter ones, I suggest Electrum. If you want to use existing addresses of staffs to sign the transaction, Coinb.io will be a good choice. You must download the zip and better not to upgrade it.

P.S. Electrum have limitations, i.e., you can only create 2-of-2 or 2-of-3 which isn't good if you want more than 2 staffs to approve the transaction.

Edit: Tutorials:

Armory: http://bitforum.info/t/armory-lockbox-multi-sig/271
Coinb.in: http://www.deepdotweb.com/tor-bazaar-multisig-guide/ and
Electrum: http://www.deepdotweb.com/2015/03/21/multi-signature-transactions-electrum-2-0/ and https://gist.github.com/atweiden/7272732 (coders).
mSIGNA: http://www.nicolascourtois.com/bitcoin/paycoin_multisig_tutorial_3e.pdf
Coinkite: http://blog.coinkite.com/post/102291566521/bitcoin-multisig

And how do they sign the transactions?

Like normal addresses. Assume there are 6 staff and you need at-least 5 staff to approve the transaction. You create a 5-of-6 multisig address. This is how you create a transaction:

#1: Staff-1 create a transaction and sign it with his/her key.
#2: Staff-1 sends that signed transaction to Staff-2.
#3: Staff-2 signs it with his/her key and sends the signed transaction to Staff-3.
#4: Staff-3 signs it with his/her key and sends the signed transaction to Staff-4.
#5: Staff-4 signs it with his/her key and sends the signed transaction to Staff-5.
#6: Staff-5 signs it with his/her key.
#7: Staff-5 broadcast/push the transaction.

If you want all(six) staffs to approve the transaction, then you create a 6-of-6 multisig address. If you do, there will be a slight change in steps.

#6: Staff-5 signs it with his/her key and sends the signed transaction to Staff-6.
#6: Staff-6 signs it with his/her key.
#7: Staff-6 broadcast/push the transaction.

I would recommend multi sig Armory. UI s not the best possible but it does the job.