User talk:Ryanc
Suspicious minds
Could you please explain what you found suspicious about my Brainwallet edits?
Same Ryan Castelluci from DEFCON talk?
First, if you're the same Ryan from the DEFCON talk on Brainwallets, thanks for publishing your research and increasing awareness of the issues. Your talk was one of the inspirations for adding Warpwallet to BitKey.
However if you're the same Ryan that leaves me confused, because you recommended Warpwallet yourself in your talk, and you should know the Warpwallet challenge for an unsalted 8 character password lasted for 2.5 years before it expired.
Do you disagree that using Warpwallet with a strong passphrase (e.g., eight diceware words) and an e-mail salt would provide very good security, unlike bitaddress-style brainwallets of old?
The problem with trusting RNGs to generate your wallet keys are very real:
http://www.zdnet.com/google-confirms-bitcoin-theft-vulnerability-in-android-7000019431/
Reply
Yes, that is me. In my talk, my comment about WarpWallet was intended to mean "if you still want to do something like this, at least use warpwallet instead". I regret that it was not phrased more clearly. WarpWallet is merely a bad idea (without a seed, it's about 60,000 times more work to crack on CPU) rather than a catastrophically foolish one.
Even if WarpWallet with eight diceware words is secure, I don't think that should be recommended because I believe people will not follow passphrase creation advice.
I am aware of the challenge wallet the WarpWallet creators made. A large botnet (several million nodes) could crack it in a few months (assume 10 guesses per second per node).
Tools that provide a random seed and do not allow free text entry are fine because it would take a lot of effort to use insecurely. WarpWallet is easy to use insecurely, electrum, armory, and bip39 are hard to use insecurely.
As far as bad RNGs go... I think people are safer trusting the RNG of reputable bitcoin wallets than trying to provide their own entropy. If a widespread vulnerability in those wallets is found, it would pose an existential threat to bitcoin.