Bitcoin Forum

Was hoping to get an answer from the technically minded on here.

Is it possible to create a wallet, or address, that can only send btc to specific, nominated addresses?

I thought this may be possible by using a smart contract and would like to hear if it is possible.

No.  Sounds like an x-y problem.  What is the "X"?  What are you trying to accomplish?

I'm pretty sure currently that something like that isn't supported by Bitcoin itself. However, you could probably implement something like that using a Blockchain wallet and its API.

For example, a magazine subscription.

I set up an address with 1 btc in it. I use this specific address to pay for the magazine subscription. In order to make it secure, I nominate that my address can only send to the magazines nominated address and possibly another of my own addresses (in order for me to transfer funds out if I discontinue buying the magazine).

What exactly is this supposed to accomplish? If you can move money to your own address at any time, how is that different from just having the money in your own address in the first place? And if you can't move money to your own address, why not just give all the money to the magazine and ask for a pro-rated refund if you change your mind?

Or the magazine can send out a monthly invoice to their customers and only mail the magazine to those who have made payment by the mailing date.

If my wallet is compromised then funds at that specific address cannot be moved away from my control.

And, I hope it would be easier than giving a service all my bitcoin and then having to ask for a refund if I want to change or discontinue my service. I have had issues in the past with subscription services charging beyond time or overcharging after subscription has been changed.

I suppose it might be a way to compartmentalise my funds.

Thanks for the replies, I had no idea whether this was useful or necessary but I didnt have the tech know how to flesh it out.

Except they can. If you can move the funds to your own address, so can whoever compromised your wallet. And because they've compromised the wallet, they can then move the funds from your address to their own.

Fair enough. But if I have separate wallets, lets say a hot wallet and a cold wallet, if my 'back up' address is my cold wallet, then I'm supposing that it wouldnt be under threat? (ie if a hot address could only send to a cold address and 1 other address.)

I am thinking that any kind of recurring payment for services will more than likely be kept 'hot'.

I think OP's requirement boils down to keeping one's private keys safe.

Just sign your transaction offline.

There is one thing that you can do. You can have an address to which you send multiple transactions of the exact amount needed for your monthly subscription. Then you create two transactions for each of those inputs. One transaction spends the input to the magazine's address and the other transaction spends it to your cold wallet. You sign those transactions and then delete the private key for your address. Now you can only send to the magazine or your cold wallet.

This is something worth trying!