It is evident that multisig is the most important thing in bitcoin in these days.
I have personally taken a look of what is possible to test today and here's what I have found.
There are at least three very interesting groups of smart people who are offering solutions based on multisig P2sh technology:
- Bitgo.com
- Cryptocorp.com
- Greenaddress.it
What I have understood:
Bitgo.comIt's ready to be explored by the end user. I have personally spoken to Will. He has been very nice to me in explaining the "pending" state of the transaction (which is due simply to confirmation phase). It is still hard to use it on a mobile but I have understood that it's going to improve.
At Inside Bitcoins conference they have announced the "corporate wallet" in which the spending authority can be shared among various members of an organization.
I think this is today the most straightforward solution to start to use multisig technology.
The controls they do before signing the transaction are still in an initial phase and you cannot set any of them (at least in the normal individual wallet). The corporate wallet is much more advanced. In this environment you can set daily expenses and other "brakes". I have been told they are thinking about extending some of the features also to the individual wallet in the future.
The three keys are generated and stored in your browser and they resides in the local storage. Two of them are printable and storable (together with the script). [from:Bitgo]BitGo only ever sees 1 of the 3 keys in a multi-sig wallet. That key is generated on their servers and stored securely [please see their post below for further details].
In this way you are substantially in control of your money because you keep two keys sufficient to move your money (it is better to keep one of them offline in a safe place).
Cryptocorp.coIt is not yet usable for a semi-geek like me. I am extremely fascinated by the concept:
You create the keys in the way you like and you give one of the private keys to cryptocorp. When you make a transaction automatically the service should perform a complex reasoning on the risk of the transaction based on you habit, your actual balance and I don't know what else and give your transaction a risk rate.
Based on the rate the service can sign along the transaction, ask you for a second factor authentication or also refuse to sign it.
I think their approach is very peculiar and for this reason they add a very special thing to the landscape of the offering in this field.
Greenaddress.itWith greenaddress.it you are a shareholder of 50% of the share of your bitcoins for limited periods of time and this is maybe for a good reason (I was skeptic at first).
For what I understand they want to "secure your bitcoin" but also to be a reference point for all your counterparts who are warranted by the service that you are not trying to double spend.
You hopefully receive in return, when the service will be understood and trusted, an immediate trust to the transaction by your merchant and you won't have to wait to leave the shop.
For the merchant the fact that the transaction come from a service that controls double spending attempts should be of some warranty per se.
You can set a time at the end of which you can withdraw all your funds through a website they have set up for this purpose (
https://greenaddress.github.io/gentle/#/view1). In this way you can have the total of control of your money back.
I personally find this idea very good for day by day expenses if the merchants start to rely on their reputation as a double spender preventer.
The problem in my opinion is that the nLockTime transaction and the solution in general is hard to explain and to trust for the normal user.
The service come with the most rich parametrization of the expenses to date (not available yet) and with an android app, four different type of second factor authentication and hd wallets.
This last characteristic is very interesting because you can and actually give always a new address to be payed to but they share the same seed with the usual benefit of being able to backup only the mnemonic.
As a side note I have not obviously had the chance to test Cosign (by bitpay) but the mock up is fantastic.
I find all this services a fantastic new possibility and I have written this to outline especially the
differences among them I have noticed.
Tell me your opinion and point out my errors or misunderstandings.
I think it is crucial to develop different services that cover different needs for the end user and the multisig technology give this possibility.
EDIT: 1. corrected the part regarding the key generation with Bitgo
2. The parametrization of the expenses on greenaddress.it is not yet available (corrected).
3. Corretto il sito di cryptocorp (non é .com)
