How to secure a Bitcoin
How to secure a Bitcoin


A Swiss bank account in your pocket. Bitcoin multiple signature (multisig) addresses maximise security against loss, theft, hack and seizure due to the nature of the split responsibility and / or redundancy required for spending. By way of explanation, let's say I want to start a family fund, in Bitcoin. I make a 2 of 5 multisig wallet; 2 signatures required of 5 possible to spend from this address. Of the 5 generated keys, I send one key to my father. One to my mother (they live separately). One to my brother. I keep one and I send a backup paper key to a trusted family friend. Requiring at least 2 signatures immediately cuts almost any unintentional loss. Let that sink in. It is almost impossible for anyone to seize, steal, hack the funds away. It is almost impossible for you to lose access to the funds. Instant spending is easy enough with any 2 members present. Businesses, Trusts or Governments might require more signatures to avoid collusion. Herein I provide a detailed explanation and code of how to create and use your own multisig address. Full code can be found at our Github page

Multisig

Keys

Multiple signatures require multiple keys. To generate fresh keys we use the random key generator provided by bitcoin.

from bitcoin import *

# private keys
k1 = random_key()
k2 = random_key()
k3 = random_key()
k4 = random_key()
k5 = random_key()

print("Private keys: these are the keys you need to disperse. Do not save copies. It would defeat the point.")
print(k1)
print(k2)
print(k3)
print(k4)
print(k5)

# public keys
p1 =  privtopub (k1) 
p2 =  privtopub (k2)
p3 =  privtopub (k3)
p4 =  privtopub (k4)
p5 =  privtopub (k5)
        

 

Redeem script

We can use the above keys to generate a redeem script and multisig address.

k = 2 # signitures required
n = 5 # keys generated

script =  mk_multisig_script ([p1 ,p2 ,p3 ,p4 ,p5], k, n)
address = scriptaddr(script)

print(script)
print(address)
        

 

Spending

Now you have a multisig address with the redeem script and keys to distribute. To test the spending, you will need to send some bitcoin to your new multisig address. Once sent, you can test the funds were received with:

unspentData = unspent(address)
print(unspentData)

unspentOutput = unspentData["output"]
          


To spend funds you will need any 2 of the 5 generated to sign the new transaction.

spendSats = 10000 # satoshis to spend
addSpend = '112eMCQJUkUz7kvxDSFCGf1nnFJZ61CE4W' # address to receive new transaction
tx =  mktx (unspentOutput, addSpend+':'+str(spendSats))
print(tx)

# Now, let’s sign it with keys 1 and 3:
sig1 =  multisign (tx, 0, script, k1)
sig2 =  multisign (tx, 0, script, k3)

tx2 =  apply_multisignatures (tx, 0, script, [sig1, sig2])
print(tx2)

# And now we push:
eligius_pushtx (tx2 )
            
                      


Financial sovereignty. It's that easy, thanks to Bitcoin.


AlexanderBradley
AlexanderBradley

http://sunflower.capital


How to secure a Bitcoin
How to secure a Bitcoin

A Swiss bank account in your pocket. Bitcoin multiple signature (multisig) addresses maximise security against loss, theft, hack and seizure due to the nature of the split responsibility and / or redundancy required for spending.

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