This module explored Peter Todd’s cypherpunk brain wallet method for securing Bitcoin. It demonstrated how five strong, memorable passwords can be memorized, concatenated, and used to encrypt a wallet with high entropy. While this method offers an unmatched level of personal sovereignty, it also carries a serious risk—if you forget, it’s gone forever. The approach is not recommended for most users but remains a legendary example of extreme Bitcoin security. In a world of hardware wallets and multisigs, Todd’s method stands as a testament to the power of the human mind.