Derivation of strong Bitcoin keys from lower-than-standard entropy secrets
Seed phrases were introduced in Bitcoin wallets in 2013 as a human-readable representation of cryptographic secrets, intended to be memorized rather than stored. However, most users struggle to reliably memorize even a short list of random words, creating usability and security trade-offs. This talk explores alternative approaches to Bitcoin key recovery based on entropy extraction from human-memorable data sources. The talk includes: - extracting the secret data from biometrics and real-world objects - combining it with the password and PoW to receive a reliable Bitcoin key with enough security bits - constructing the Bitcoin address in the way it can be recovered if the primary key is lost Finally, the talk will present an economic analysis of the system parameters including PoW difficulty, secret length, locktime, and attack costs needed to achieve the optimal solution from both security and time perspectives.