5 ms·

Just as a warning to people that might want to try this, a lot of work has gone into monitoring the addresses tied to private keys created from potential words.

• toomuchtodo 6y ago
  You could also store your private key on an RFID tag implanted under your skin (also MRI safe).
  • umvi 6y ago
    Security through obscurity is best here. Just shift all the digits of your key by some secret (but very simple) algorithm and store in google drive.
    • ohazi 6y ago
      WTF, do not do this. You can use real encryption, like GPG in symmetric mode with a memorized passphrase that gets properly key-stretched. Then store the resulting uniform random-looking blob in image metadata or whatever. Obscurity is to prevent them from asking you what's in an obviously encrypted file like "bitcoin_wallet.dat.gpg," it's not for actual protection if they do happen to focus on you.
      • umvi 6y ago
        > Then store the resulting uniform random-looking blob in image metadata or whatever. Steganography is still security through obscurity. I don't see how it's any more secure than storing a manipulated key in plain text, especially if you are competent. If it were me I would just xor my address with a key of the same length (correcthorsebatterystaple-esque) and then xor it back out on the other side. How would you even know it was a bitcoin wallet address vs. something else? Or even write a letter to someone, where the second letter of the first word of every paragraph form the wallet address.
        • AgentME 6y ago
          >How would you even know it was a bitcoin wallet address vs. something else? The fact you talk about doing that sort of thing would be a big clue. The benefit of using proper symmetric encryption (like GPG, or even better, age[0]) is that even if you talk about or even fully explain your process, then it's still secure as long as you don't post your key. [0] https://age-encryption.org/ https://age-encryption.org/
          • umvi 6y ago
            If you use "proper symmetric encryption" you have the same problem as before: how to smuggle the key over the border assuming they will search your person and online accounts ...?
            • AgentME 6y ago
              Oh sorry, I think I'd lost that bit of context. This scenario of hiding a password during inspection is probably the main place where "security through obscurity" has validity. A big benefit of encrypting your cryptocurrency private key with a password and then hiding/obscuring that password instead of the raw private key itself is that good encryption will apply key-stretching to the password, making it harder to brute-force. If an attacker finds a random-looking value in your stuff, and believes that the value might be your bitcoin private key XORed by a short string, they it's very cheap for them to check whether each result is a valid bitcoin private key. There might even be structure in the bitcoin private key format that helps gives away the XOR key. But if they know your bitcoin private key (or something else) is encrypted by Age, and they find a random-looking value that might be your password XORed by a short string, then because Age uses scrypt on the password, then it will take longer for them to verify each attempt against the ciphertext.
            • ohazi 6y ago
              It's not difficult to memorize one reasonably good passphrase, and there are well-known key-stretching algorithms that are understood to provide however many bits you need of actual security from this passphrase. > Just shift all the digits of your key by some secret (but very simple) algorithm You are basically suggesting that people roll their own crypto here. Or pseudo-crypto, or stego, or whatever you want to call it. Don't tell people to "Just do X" when the ambiguity in the methods that you describe leave >90% odds that the result of their work won't even pass a statistical uniformity test. This leaks the key. Once your adversary realizes that you made some sort of mistake here, they can write software to make their attack orders of magnitude easier than it would otherwise be.
• martinko 6y ago
  BIP39 (https://github.com/bitcoin/bips/blob/master/bip-0039.mediawiki https://github.com/bitcoin/bips/blob/master/bip-0039.mediawi...) mnemonics are the industry standard for deriving keys. If you use enough words (the standard will not let you use less than 12), then you are completely fine.
  • csomar 6y ago
    The problem is if you come up with the words yourself, you are most likely to screw up. So people should be aware that they should use a random number generator.
• pixelperfect 6y ago
  If you wallet is using the BIP39 standard you just memorize the 12-word phrase. The words come from the key, not vice versa. Also, you can get by with just memorizing one phrase, because unlimited addresses are tied sequentially to a single phrase.
• kylebenzle 6y ago
  You are wrong, please remove this comment.
• AgentME 6y ago
  Brainwallets, where you choose the phrase that unlocks the wallet, are a bad idea for this reason. Plenty of people have lost a lot of money from trying clever things like using their favorite line from a piece of media. However, if you have a seed phrase of 12 randomly-chosen words (that were properly randomly chosen by software, not a person), then that's enough to be safe.