Thanks, so I will do the following then, as BIP39 describes:

• Generate the initial entropy
• Create the seed using the mnemonic + a passphrase

With those additional steps:

• Store the mnemonic in a QR Code
• Print it and paste it on the gift

Hello,

I don't want to reinvent the wheel => this is why I tried to start from something existing I knew (the warp wallet) and why I post on this forum, so I can learn about stuff like the extra word in BIP 39 
So, thanks a lot for your feedback.

Pooya perfectly summarized it, right now my algorithm creates 256 bits of entropy and the password only add a bit more.
Actually, this is BIP39 + passphrase but with argon2 instead of pbkdf2 and a QR code instead of a wordlist.

I asked my girlfriend to create a 8+ letters passphrase, let's say I use BIP39, send 100 USD and post here the mnemonic, as if the qr code would have been compromised.
Do you think the cost to brute force would be low enough so people will try?
Do you think it would make a big difference if I use argon2 instead of pbkdf2? (I understand this would break compatibility)

thanks

Thanks for all your replies,


So you think the warp wallet algorithm with argon2 and pbkdf2 does not strengthen it enough?
We are talking about wallets of 20-50 USD. I would have thought that even with the QR code stolen, brute forcing would cost too much.

Yes this sounds a great idea, I should use BIP38 instead of my proposed algorithm, then?



I want to offer this also to my friends, a different present for each of them.
I already offered a funkopop with a QR code to a friend and he was very happy to have crypto money.
Think of a painting for someone, a key chain for another etc. All of them with a QR code.


The random seed is the QR code.
I felt the QR code is more friendly to print on something and more friendly when you scan it.

Yes, I want to open-source the algorithm.
I was also thinking of a website, you load it, get offline and then you can scan the QR code and enter your password, to get your private key.

The idea is not to create a multipurpose wallet, this is more like "my first crypto", so people can enter the crypto world, lose their fear about it and then maybe one day will get serious with other wallets.

Hello Charles,

This is because I want to give her not only the QR code, but a nice object with the QR printed on it.

So she can "feel" it, something she could put in her home and show her hosts she now has bitcoins.

Hello,

I plan to create a brain wallet by doing the following:

* Create securely a random seed and print its QR code
* Use the https://keybase.io/warp/warp_1.0.9_SHA256_a2067491ab582bde779f4505055807c2479354633a2216b22cf1e92d1a6e4a87.html algorithm  with my seed as the password and a classic/human-made/weak password (that my mother can remember) as the salt.
* Instead of using Scrypt, use argon2
* Generate a wallet
* Send some satoshis
* Give the QR code to my mum as a gift

Do you think it is secure enough?

Thanks