Few days ago I wanted to create cold wallet, but needed wallet app to create seed words.

My plan was following:

• 1. Factory reset old mobile phone
• 2. Connect it to wifi and download Blockstream Green wallet
• 3. Disconnect mobile phone from wifi
• 4. Generate seed words and few addresses
• 5. Write down seed words and scan addresses with other phone
• 6. Factory reset wallet again

It sounded great at first until I installed Blockstream wallet and disconnected mobile phone from wifi. To my surprise I got an error "Error connection failed". I was wondering why would wallet need Internet connection in order to generate new wallet? Why can't it pick 11 words and calculate checksum without Internet connection?

To me it sounds like possible security weakness. I'm not saying it is deliberate and don't want to accuse Blockstream of anything, but it does rise a red flag.


At the end I used Bluewallet app which also gave me error when I tried to generate seed offline, but I managed it in the end.

Anyone had similar problem? What could be good alternative to Blockstream app to generate BIP 39/ BIP 44 compatible wallet ?