What is Multi-Sig (Multiple Signature)
Typically a Bitcoin transaction is signed with a single key. One key to authorize moving Bitcoin from one address to another. This functionality is not sufficient for some use cases. The simplest example would be a 2-of-2 multi-sig, if this kind of contract is setup, you will have to supply 2 keys to allow the network to move your Bitcoin.
A typical example of how this would be useful is a 2-of-3. On the creation of the contract you would supply 3 keys, any transactions would require 2 of them to be supplied. So, we can imagine the “owner” of the Bitcoin giving one key to a lawyer, one to a trusted family member and one for themselves. This way if any one of the keys are lost, you are able to access the Bitcoin using just 2 of the keys.
