Bitcoin Forum

Hi

I have seen some websites that have an address that starts with a 3. For example Bit-X and some multisig addresses.
They are all valid, but I have no clue how to get one.
Are they normal addresses? Is there any way to vanity gen one?

Thanks

That is a multi-sig address.

Here: https://en.bitcoin.it/wiki/Multisignature (https://en.bitcoin.it/wiki/Multisignature)

here you go

https://bitcointalk.org/index.php?topic=365550.0


hope it helps

Thanks man! Have been searching for this for a long time!

Or in case you are a visual learner there's a couple videos on youtube. James D'Angelo does great videos but his demonstration uses a custom python script, so if you want to follow along with his you need to download that and run python along with your wallet. The 1st one is how to do it in bitcoin core wallet. The second video shows you how to do it through SSH with bitcoind and rpc commands.

Bitcoin Core Wallet - How To Create a Multisig Address and Spend From It  (https://www.youtube.com/watch?v=YN2Vyu9RupU)
Bitcoind RPC - Bitcoin M-of-N Multisig Addresses (https://www.youtube.com/watch?v=ZKRLJGBMqWo)
Python RPC Bitcoind - Bitcoin 101 - Multi-Signature Addresses (https://www.youtube.com/watch?v=zIbUSaZBJgU)

Greenaddress.it

bitaddress which generates paper wallets I believe gives you an address with either 5 or 3.

No.

There are currently no standard bitcoin addresses that start with a 5.

There are five different initial characters for standard bitcoin addresses:

• 1 - All standard Pay-to-pubkey-hash (P2PKH) addresses start with a 1
• 3 - All standard Pay-to-script-hash (P2SH) addresses start with a 3
• m or n - All testnet Pay-to-pubkey-hash (P2PKH) addresses start with either an 'm' or an 'n'
• 2 - All testnet Pay-to-script-hash (P2SH) addresses start with a 2

All I see above are online methods. Is there any way, I can create MultiSig address offline, like I can do with the bitaddress code ?

Sure.

• Disconnect computer from internet
• Install Bitcoin Core
• Choose the "Receive" tab
• Click the "Request Payment" button
• Store a copy of the address generated that starts with a 1 (I'll use the phrase your_address_here later to refer to this address)
• Choose "Help" from menu
• Choose "Debug Window"
• Choose "Console" in the Debug window
• Type: dumpprivkey your_address_here
• It would probably be a good idea to securely store a copy of this private key
• Type: createmultisig 1 '[your_address_here]'
• Store a copy of the address generated that starts with a 3
• Store a copy of the redeemScript
• Remove Bitcoin Core from the computer

Apart from Bitcoin Core which Danny suggested above you can also use latest version of Electrum (https://electrum.org/#download) which supports Multisig and I believe it can be done off-line. cmiiw

Read the guide here: https://electrum.orain.org/wiki/Multisig_Wallets

But make sure you understand what you're doing and that you can send funds from the multisig address before storing large sum of btc in it. The best way to make sure is send a small amount of bitcoin say 0.001 to it and then try to send it to another address.

Some people also suggested on reddit (https://www.reddit.com/r/Bitcoin/comments/35ks4c/is_there_a_guide_on_how_to_setup_a_multisig_wallet/) that it can be done using coinkite & coinb.in too but I don't know if it's secure or not therefore I can't recommend it but you can read more about those and see if you find them safe and doable.

Hello , I think an address that start with 3 is an green address , i know two apps or site that can
do it :

greenaddress.it [Recommanded]
copay.io [Good too]

Xing Ming .