I have been asked to recover some tether that have been sent to the wrong address... Sitting on the blockchain in a multisig copay account.

I have written small php command line tools to reproduce the case and learn more about how Bitcoin works. I am a software developer working mostly with NEM where the blockchain is very different. I have learned a lot about multisig on Bitcoin, OP_RETURNs used in omni (usdt being a smartproperty on the omni layer), and many more awesome things about hierarchical key generation, key derivation functions, and many more subjects.

Script are written in PHP with laravel/zero and can be found here:

• BIP32+44 HD Addresses Generation Tool on Github

• BIP39 Seed Derivation (get Private Keys) on Github

• My P2SH Colored Transaction creation on Github

But I struggle getting back those tether to another address. Of course, I own the 3 cosigners configured with copay, but I am too much of a noob to get those tether back. Fact is, the NEM blockchain is very different when it comes to multisig and custom assets. So I went through the learning process for HD keys and XPRV and XPUBs. Which I also built a command for. A command that, provided with the right derivation path and xpubs or mnemonics, will generate the same cosigners xpubs as copay displays in the multisig wallet information page.

Here is a link to the BitcoinTalk thread where you will find a screenshot and more details about the transaction i am trying to create. Maybe someone here might help as this requires deep understanding of Bitcoin Multisig, HD Key Derivations, OP_RETURN and Colored Coins.

The challenge is quite amazing and let me learn tons of things, but watching serialized data I think I am getting crazy, I can't get it done, please hAlp ! x:)

PS: <3 Bitcoin