What is checksum used in BIP-39 and what is it for? I don’t trust programs that generate 12 words, since I don’t know what algorithm they are working on, and for this I wanted to take 12 words from the total 2048 bip-39 word list, but if I do, and after that I want to get using my words to access my wallets, for example using this script https://github.com/iancoleman/bip39 I get an error Invalid mnemonic.

I'm in a dead end, I'm afraid if I use the 12 words that I chose from the general list, because of the checksum error, I will lose my bitcoins in the future, please clarify. I'm at a dead end, I'm afraid if I use the 12 words that I chose myself from the general list of words, I will lose my bitcoins in the future because the programs will not want to accept my words, because of the checksum error. You can help me? How can I convert my 12 words that I chose myself, from a list of 2048 words, into a wallet?

At the moment I can choose any 12 words at my discretion, and Electrum will accept them, but with an unkown wordlist error.

Can you explain to me how the checksum check works, and what is it for in BIP-39?

Using the google authenticator is not secure

Thanks for the answer! I also have an idea how to protect your private key if it falls into the wrong hands so that you don’t lose money. You can change one or two characters in your private key, put a small amount of bitcoins on the changed private key, and keep all your balance in a private key about when you only know one or two characters that you need to change in your private key in order to access your main Bitcoins. In the event that your private key is stolen, the attacker will receive a small part of bitcoins, you can create two backup copies, and in case you know exactly which characters you need to replace, in your case, the private key in order to gain access to your main bitcoins. What do you think about it? It looks very safe, and even if you are tortured with a soldering iron, you can give your private key to an attacker, and then use your second backup in which you will need to replace 1-2 characters in your private key in order to get access to your main bitcoins . If nobody knows about your secret with the replacement

Creating a wallet using bitcoin.org you cannot know with what algorithm the sha-256 key was created, and what was used to create it, and therefore you cannot be 100% sure that your bitcoins are secure if you are not Create a private key from your phrase or characters. If you create your private key yourself, using my method of pressing the keyboard many times, typing absolutely random letters and numbers, and then encrypting your randomly typed phrase into the private key SHA-256, you will be sure that the private key The key is created from a strong phrase that can not be cracked. If I'm wrong, correct me.

People poorly create Brain wallets, using words or phrases that other people can predict, in my case, I just press the keyboard with two hands and get completely random characters that no one can ever repeat and create a private key such as I have.

Will it be safe to create a private key by encrypting absolutely random letters in SHA256, for example 'sdfguhiuwrUISDHGNIUXHIUCV238778dfvhgjhuidsahgfiu', encrypt these random letters and numbers in SHA-256 and use the resulting private-key for bitcoin? I can do this with the Internet turned off, I can encrypt the absolutely randomly typed phrase 'sdfgdhfsuyghuHUDUIHGHIUG878yet7y8bchxujxcbvhidsafhguihuq' in SHA-256, write the received private key and use it to use Bitcoin? Why use some kind of generators, when you can encrypt any randomized characters typed on the keyboard, and use the resulting private-key for bitcoin? After all, in fact, no one will know the phrases with the help of which the private-key was created, and the only way to lose it is if someone other than me gets access to the private key.