The Best Multi-Signature Wallets for Bitcoin
What is a Multi-Signature Bitcoin Wallet?
A multi-signature Bitcoin wallet, sometimes abbreviated to simply a 'multi-sig' wallet, is a piece of software for receiving, storing, and sending Bitcoins which requires two or more people to authorize every transaction.
What that means is that in order to spend money from a multi-signature wallet more than one password is required, and these passwords would usually be known and controlled by different people.
Having this requirement for more than one person to authorize transactions adds an extra layer of security onto a Bitcoin wallet, because even if one person's computer is hacked into by thieves, or if one person's password is compromised, the funds held in the wallet are still safe. A user who only makes occasional payments may choose to have a friend or family member act as the second signature on their account, or a business may offer to co-sign transactions if you go through an additional identity verification procedure in order to help you improve the security of your wallet.
Joint authorization can also be used by family members to set up joint accounts, in much the same way that you may have a joint bank account.
Another use for multi-signature wallets is within business, where one person may adminster the finances, keeping the books in order and initiating payments, but another person may need to 'sign off' on payments before they are actually sent out. The use of a multi-sig wallet makes this common business practice much quicker and easier.
Copay - Multi-Sig Desktop Wallet
Copay is an open source, decentralized software system for creating multi-signature wallets.
The Copay software was developed by the popular digital currency payments processor Bitpay for their own internal use within the company, and was subsequently released to the public under an open source license which means that anybody can copy the code and create their own version of Copay, as long as they share any improvements or additions they make to the code.
The software is almost entirely decentralized, requiring only a small amount of contact with servers, which anyone can set up and run themselves, and storing coins locally on the user's own machine. Over time Bitpay hope to make this software completely decentralized by removing all requirements for central servers.
Copay is currently available as a browser extension for Chrome or Firefox, or as an Android app. There is also a web wallet version of the software.
BitGo was the first company to release a multi-sig wallet, and today boasts of 'bank grade security for your Bitcoin'.
The BitGo system produces 3 keys for every wallet, 2 of which are required to authorize any transaction. You are given two of the keys, whilst BitGo themselves controls the third.
In addition to multi-sig capability the BitGo wallet also offers 24/7 monitoring and alerts, and an enterprise account option with spending limits, corporate treasury policies, and additional approval requirements for large transactions.
MultiSig+ is a multi-everything wallet. Not only is it multi-signature, it is also multi-currency - which means that you can use it for Litecoin and Dogecoin as well as Bitcoin, and there are even plans to expand this to cover a range of other digital currencies as well. Not only that, but it also describes itself as having 'multi-factor' authorization, meaning that more than just a password is required to log in.
All of this makes MultiSig+ so secure that al paid accounts come with a 125% guarantee, so that if any coins are stolen from your wallet the company behind this product promises to pay you back everything you lost plus an extra 25%!
All accounts have a primary account holder who can authorize transactions, and a set number of additional account holders who may only be able to initiate transactions but not authorize them.
A range of membership plans are available, from the free starter package which limits you to a maximum of 5 multi-sig transactions per month, up to the enterprise plus package which allows for unlimited transactions, up to 5 admins, 15 authorized authenticators (to approve transactions) and up to 100 additional users.