[tl;dr: I need to elaborate a procedure to store bitcoins securely, with all the paranoia I can afford to deal with. It needs to be impossible to forget my credentials, to get hacked or to lose everything due to "storage issues".]

I work in IT and a friend of mine that has a vast knowledge in hacking doesn't believe in the potential of Bitcoin.

He says things about bitcoin not being "backed by gold", that the encryption can be broken, that "some exchange in 2015" had disappeared and the money just vanished, or about the MT.Gox incident. I tried to argue but he didn't really listen.

So he proposed to me that he could give me 10 BTCTC, but if I lost it or if "the bubble bursted", I would pay it to him at least two times worth. If I manage to secure it and the value increases, I get half of the profits.

So I need to prepare for him a document with the procedure to generate a safe wallet, safely access it with no traces, hold the bitcoin for some months and present the profits on his table. The problem is I don't know a lot about hardware wallets, becoming a fullnode or how to use a paper wallet.

Anyway, he doesn't really expect to break the blockchain's encryption, I think. He just thinks I would be foolish to leave my bitcoins on an exchange, leave traces, execute the procedures on my usual network with no VPN and on my usual computer, save my private keys on a text file or something like that. I bet he is planning to get access to my wallet, recover all the bitcoins and then "forgive" my debt, like a good friend would do. Well, I won't let that happen.

tl;dr: I need to elaborate a procedure to store bitcoins securely, with all the paranoia I can afford to deal with. It needs to be impossible to forget my credentials, to get hacked or to lose everything due to "storage issues".

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[edited]

I have a notebook that I don't use anymore, with a 320GB hard-drive, so the blockchain fits. I will use a bootable tool to cleanse it's hard drive once and for all, and I won't connect the notebook to the internet until I've got Tails Linux running. Anything I do on this notebook will be for opening the fullnode (or eletrum client) and storing my bitcoins.

What do I need to access the bitcoins contained on my paper wallet? Is Eletrum fully trustable? Is there any way I would lose my bitcoins with it, if used with Tails Linux and taking all the necessary precautions?