On an air-gap computer (meant to be a raspberry pi in the near future) that was never connected to Internet, following my own entropy scheme (using a 6-side dice and different easily auditable platform-independent / multi-platforms applications such as bitaddress.org), I have securely created different private keys for long-term deep cold storage bitcoin addresses - destined to hold not only my bitcoins but more importantly those of my family members and close friends (so I can't mess up).

So I am now looking for someone able to develop a highly secure, easily auditable, platform-independent (not based on electrum or armory) and evolutive solution to sign offline transactions from these cold storage addresses. The proposed offline signature solution must:

. Take into account that these cold storage addresses may sometimes be multisig addresses;
. Be easily upgradable as the Bitcoin protocol evolves.

The whole solution should be able to also be ported on raspberry pi running ubuntu or tails or similar.

Selection of the developer will be based on his capacity to demonstrate perfect understanding of the Bitcoin protocol and of my requirements - as well as to provide a simple, easily auditable, and evolutive solution. Bounty to be determined directly with the developer of the project.

Hi,

A few days ago I made a few transactions - paying each time the usual 0.0001 BTC fee - with the following addresses (involving tiny amounts for testing purposes):

1NFo5qAsCm5Uc633LdivSu7QUF2kh2PSrw

1BA4xtowWC3HqsYWwWZcKmKLmUgSaw9diG

1P4nHtswu8CiZDHiPZX486m35BedGpk1gX

None of the transactions have confirmed yet and at this stage I really don't know why and what to do - as I have already checked the details of the transactions (with a couple of debug tools) and could not find anything wrong. Help would be greatly appreciated as I intend to store fairly large amounts of btc on these cold storage addresses but first really need to identify what went wrong. Thanks!

Hello,

I have created safely different private keys for long term cold storage addresses on an air gap machine using dices and different easily auditable platform-independent / multi-platforms software like bitaddress.org

After creation of these cold storage addresses, I made a test to redeem funds from them - before committing on storing larger amounts of bitcoins on them.

So I have been looking for secure and easily auditable platform-independent / multi-platforms ways to sign offline transactions from these cold storage addresses (the same way I was using secure and easily auditable platform-independent / multi-platforms to generate private keys).

So far I found only  two tools to do so and I used both of them. These tools generated raw transactions that I carefully checked before broadcasting them using https://blockchain.info/pushtx

These 2 tools are:

https://www.strongcoin.com/downloads/offlineTransaction.zip

http://offlinewallet.appspot.com/

However, the offline signed transactions generated through these 2 tools would not confirm and I don't know why (of course, I don't care about the tiny amounts of money involved - as this was just for testing purposes before committing larger amounts of btc, as I said at the beginning).

Here are the 3 cold storage addresses involved in these different non-confirmed transactions.

1NFo5qAsCm5Uc633LdivSu7QUF2kh2PSrw

1BA4xtowWC3HqsYWwWZcKmKLmUgSaw9diG

1P4nHtswu8CiZDHiPZX486m35BedGpk1gX

Therefore I am still stuck on finding a secure and easily auditable platform-independent / multi-platforms to sign offline transactions). I dont want to use Electrum or Armory - which are not independent enough - in my opinion. Would you have any insights?

Thanks for your support!