A new type of wallet - delayed multisig

[dnydublin12]

Thinking about MtGx and particularly Bitstamp. Maybe there is a need for a new type of wallet.

Bitstamp seem to have being doing everything quite well, keeping most of the funds in offline wallets. The money that was hacked was from a hot wallet. Petty cash, if you like, which they would understandably need to have easily accessible and in a hot wallet for operational reasons.

But did it need to be an 'instant' hot wallet?

What if we had a new type of wallet, that was a type of multisig wallet. Delayed transaction multisig wallet.

Transactions initiated with this type of wallet would not be executed immediately, but would always be marked for processing, in X blocks (36 for 6 hour delay, 72 for 12, 144 for a day). The ability to post date transactions is already built into bitcoin, so would just be a matter of having a special case of multisig.

If the owner of the wallet noticed that an undesired transaction had being placed, they would be able to use a separate signature to mark the transaction as invalid.

Use case is for people and companies like Bitstamp who want to have monies in hot wallet and are happy to forgo instant transactions in their wallets, in the interest of extra security and a chance to undo transactions within a certain timeframe. Like a half way house in terms of security between an offline wallet and a hot wallet.

What do you think?

[Zendikar]

Sounds like people should just use their own wallets rather than an online one.

[mnemonick]

I think this is great idea!

I will add that there should be multisignature delayed wallets with included special "fast" address, where out transactions will be processed in normal way, fast and one-signature.
Such address will be helpful if You would like to make quick transfer of Your coins.

[dnydublin12]

You would have a different wallet for that. So you would transfer from your delayed multisig wallet into your instant hot wallet as much as you think you might need in the next couple of hours.

If you allowed special 'fast' address, the hacker could just do the same.

[mnemonick]

You would have a different wallet for that. So you would transfer from your delayed multisig wallet into your instant hot wallet as much as you think you might need in the next couple of hours.

If you allowed special 'fast' address, the hacker could just do the same.

No, because You will only have private keys for this address. I mean this private key should be not stored with private keys of multisignature wallet.

[jackjoker]

Have you work on it or just think ?

[dnydublin12]

just thinking for the moment. Wonder is there a need?

I think probably if it was something that was generally a good idea and not done before I'd email the dev group and then maybe propose a BIP (I think thats the recommended process?). I am a developer (but not on bitcoin or altcoin so far) but don't want to waste my time/their time or embarrass myself if its been done already or is not useful for some reason I'm not aware of.

[DannyHamilton]

You've asked the same question here:
https://bitcointalk.org/index.php?topic=916622.0

It's generally a bad idea to post the exact same question in two different places.

You end up with a split conversation where nobody knows what has already been said.

Here's my response from your other thread:

You'll want to take the time to really think through all the possible situations and attacks that might be possible with something like this.

If a mining pool doesn't see the second signature in time, what happens when they eventually include the transaction in a block (after X blocks have occurred)?

How would this be different from a mining pool refusing to honor the second signature and including the transaction in a block (after X blocks), or would it be different?

Couldn't an attacker eat up all of the memory (or disk space) of the mining pools by generating these transactions as fast as they can so that the pools need to store millions of transactions that aren't ready to be confirmed, and then transmitting the "cancel" signature before the deadline?