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> Steganography is still security through obscurity. It doesn't have to be. Maybe that's where our misunderstanding is coming from. The method I'm suggesting

by ohazi 6y ago

> Steganography is still security through obscurity. It doesn't have to be. Maybe that's where our misunderstanding is coming from. The method I'm suggesting is this: 1) Generate a good passphrase and memorize it. 2) Use a strong key-stretching algorithm like pbkdf2 to generate a symmetric encryption key from the passphrase. 3) Use a strong encryption algorithm like aes-256 to encrypt your bitcoin wallet using the key from step 2. 4) Use steganographic techniques to hide the ciphertext from step 3 in an image, email, executable, pdf, etc. 5) Walk across the border carrying the hidden ciphertext on a computer or a disk, and with the passphrase in your brain. This is not security through obscurity, this is hiding the fact that you're carrying a bitcoin wallet across a border through obscurity. The actual wallet is still protected using strong cryptography. You'd be perfectly safe publishing the ciphertext from step 3 online, or mailing a copy to the White House, because the protection comes from the computational guarantees provided by strong cryptography, and by your knowledge that nothing derived from key material was ever published or transmitted. It's safer to rely on strong cryptography as your fallback in case the steganography is discovered than to assume that the NSA can't figure out why you capitalized every third word in your last twenty emails to yourself. If they're going to do that anyway, let them discover your ciphertext, not your key.

umvi 6y ago
> 3) Use a strong encryption algorithm like aes-256 to encrypt your bitcoin wallet using the key from step 2. bitcoin wallet private key is 256 bits. Why not just sha256 hash a password and xor it with the private key? Seems like a decent one time pad to me and much simpler than your approach. And before you say how easily sha256 passwords are brute-forced (they aren't if you pick a password longer than, say, 20 characters) the attacker would need to know so many things that it is unreasonable to assume they would even try that. They would need to know a) my bitcoin private key was xored with a OTP b) the OTP was generated using sha256 c) anything else I did > 4) Use steganographic techniques to hide the ciphertext from step 3 in an image, email, executable, pdf, etc. If I were the leader of a totalitarian regime, I would almost certainly make my country's great firewall have extensive anti-steganographic measures. Any common file formats used for smuggling information that pass through the great firewall must first have all of its padding bits zeroed before continuing to its destination. If people start abusing metadata, metadata should be zeroed as well. > 5) Walk across the border carrying the hidden ciphertext on a computer or a disk, and with the passphrase in your brain Didn't GP say they take everything of value at the border? That would include computers and disks. "You could pass the border occasionally to visit family on the other side, but it was risky to take anything."

by ohazi 6y ago

umvi 6y ago

> 3) Use a strong encryption algorithm like aes-256 to encrypt your bitcoin wallet using the key from step 2. bitcoin wallet private key is 256 bits. Why not just sha256 hash a password and xor it with the private key? Seems like a decent one time pad to me and much simpler than your approach. And before you say how easily sha256 passwords are brute-forced (they aren't if you pick a password longer than, say, 20 characters) the attacker would need to know so many things that it is unreasonable to assume they would even try that. They would need to know a) my bitcoin private key was xored with a OTP b) the OTP was generated using sha256 c) anything else I did > 4) Use steganographic techniques to hide the ciphertext from step 3 in an image, email, executable, pdf, etc. If I were the leader of a totalitarian regime, I would almost certainly make my country's great firewall have extensive anti-steganographic measures. Any common file formats used for smuggling information that pass through the great firewall must first have all of its padding bits zeroed before continuing to its destination. If people start abusing metadata, metadata should be zeroed as well. > 5) Walk across the border carrying the hidden ciphertext on a computer or a disk, and with the passphrase in your brain Didn't GP say they take everything of value at the border? That would include computers and disks. "You could pass the border occasionally to visit family on the other side, but it was risky to take anything."