 MB asks, please advise on the safety of using only one 12 word mnemonic for all of my wallets. The hot wallets on my phone, my desktop wallet, my cold storage using different strong past phrases to separate them. The reason for this would be to simplify seed storage and create a cleaner inheritance plan and the phone, non-passphrased hot wallets could be a sort of canary in the coal mine at the same time. Is this safe? No. It's not safe, MB. I'm sorry, it's not safe. Part of the reason it's not safe is because you're effectively mixing hot and cold security, which means that if your mnemonic phrase is used for your hot wallet and your cold wallet, then it's not a cold mnemonic phrase. The mnemonic phrase has to be loaded onto an online connected device like a smartphone where it is sitting in the memory of the application, which means that any bug in that application, any bug in the operating system, any mishandling keyboard loggers or anything like that. And that mnemonic phrase is basically now compromised. So if the same mnemonic phrase is used for both hot and cold, it's hot. And then you're relying on the past phrase for basically all of your security. And that's very dangerous for a number of reasons. The primary reason is that your past phrase as a complex past phrase is not going to contain 128 bits of entropy. It's going to contain a lot less. If you make a very, very good past phrase and you know exactly what you're doing, maybe you can get to 128 bits of entropy. But now you've got another problem, which is now you have to still store all of these past phrases back up. And that's actually harder than storing mnemonic phrases because the past phrases do not follow a standard, do not have a check sum in them, are not from a specific dictionary, and you're generating them yourself instead of having a properly configured device generate that entropy for you. So if you haven't generated them correctly, they don't have sufficient entropy. Generally speaking, what you've done is you shifted the entire standardization and security model of the BIP39 mnemonic phrase into the past phrases, which are non-standard, implemented according to whatever mechanism you use, not generated securely as high entropy past phrases. And that's really not sufficient, but you still have to back them up. So you didn't really save yourself anything. What I would recommend is, at least what I do is I have backups of my hot wallet mnemonic phrases and I have backups of my cold storage mnemonic phrases and I have backups of past phrases where I use past phrases. I do not use past phrases on my hot wallet because the mnemonic is enough security and the physical security I have around my mnemonic backup is sufficient for my purposes. Plus, if I don't trust the application and operating system this mnemonic phrase is running on, then I don't trust it for the past phrase either. So the past phrase doesn't really give me anything other than inconvenience and an extra thing to back up. For my cold storage, however, I am absolutely going to use an additional past phrase because that mnemonic phrase sits in cold storage for a while, may not be accessed very often. It's a lot more important that the mnemonic phrase isn't the only mechanism to secure it and I add an additional past phrase which is also backed up and kept separately. So yeah, don't do that with your mnemonic phrases. You can use one mnemonic phrase for several different cold storage wallets, for example, with different past phrases. I wouldn't increase the complexity too much. You can use one mnemonic phrase with different past phrases for several different hot wallets. Again, try not to make things too complicated because you always have to also back up the past phrases and you can also use one mnemonic phrase for multiple different cryptocurrency. So to use it for Bitcoin and Ethereum and Litecoin and whatever else. But I would not mix different categories of risk, cold storage and hot storage on the same mnemonic phrase. That's a bad idea. If you enjoyed this video, please subscribe, like and share. All my work is shared for free. So if you wanna support it, join me on Patreon.