How to confirm transactions in an offline wallet?

[jefferson7]

I'm trying to create a transaction using an on line wallet service to get btc out of my offline core. Creating the raw transaction on line and signing it offline.

I have unconfirmed inputs/balance showing in my offline Core. Is this the reason why my raw transaction that I create on line fails when I run it through the debug window with the message "no inputs found or already spent"? I suspect its because those inputs are unconfirmed as this wallet has not been on line. How can i fix this?

I have core on another machine with the full block chain downloaded, could that be used to confirm these inputs to my offline wallet so that it can find them in order to sign my raw transaction? I know the inputs are there as I checked the address and the on line wallet found them no problem.
Or perhaps the on line wallet can create some kind of transaction to verify the inputs in the offline wallet?

How does the offline wallets balance and transaction history get updated?

[HCP]

According to the "demos" that I've seen, when you're using Core, you need to provide the input information when you're signing the transaction offline: https://people.xiph.org/~greg/signdemo.txt

Essentially, you need to provide the TXIDs, the vouts and the ScriptPubKeys and/or redeemScripts for the inputs that you're using in the transaction.

signrawtransaction "hexstring" ( [{"txid":"id","vout":n,"scriptPubKey":"hex","redeemScript":"hex"},...] ["privatekey1",...] sighashtype )

Sign inputs for raw transaction (serialized, hex-encoded).
The second optional argument (may be null) is an array of previous transaction outputs that this transaction depends on but may not yet be in the block chain.
The third optional argument (may be null) is an array of base58-encoded private keys that, if given, will be the only keys used to sign the transaction.

[dumbtool45]

Amazing how people are never reading what they are posting here.

If you want to do that you have 2 options:

Create the transaction offline and set a good fee, get online with the wallet.

Second, use a bip and input the raw of transaction.

Cheers

[HCP]

@HCP. I would like to know how it is possible to transact the bitcoin when the system is offline. If it is offline it cannot be mined with the network blocks! Can give explanation to know about it.

You don't attempt to broadcast the signed transaction from the offline machine... that is why you need 2 machines for this system.

One "online" machine that has full copy of the blockchain and only public keys... aka. the "watching wallet"... and then one "offline" machine... airgapped, with no blockchain, but with the private keys etc.. After you have created the transaction on the online machine, you transfer to offline machine via usb, sign it with the private keys... then transfer the "signed" transaction back to online machine via usb and broadcast it.


In all honesty, you are just better off getting a hardware wallet... it achieves pretty much the same thing but without the requirement for a second PC and a lot less hassle etc.