Proposal discussion: BIP39 native-language display wordlists

The primary goal is to facilitate non-English speakers in managing their cryptocurrency wallets more efficiently by reducing the errors often associated with using English-based recovery words. This proposal, while maintaining the standard English BIP39 wordlist, introduces a method where recovery phrases can be displayed and input in various native languages, corresponding index-wise to the English list. This ensures that the cryptographic integrity remains intact as PBKDF2 continues to apply to the English mnemonics.

Daniel's concept addresses a significant flaw in the current implementation of BIP39, where using different languages to encode source entropy leads to the generation of different master keys, thereby hampering compatibility. He proposes a solution that allows translation of seed phrases across languages without replacing the original BIP39 standard. This approach aims to preserve cross-language compatibility and simplify digital wallet usage worldwide. However, it necessitates clear differentiation between legacy and new "locale-mapped" seed phrases to prevent potential issues like misderived keys and subsequent financial losses.

In practical terms, the proposal suggests implementing TZUR display mnemonics which would use localized words for user interactions but keep the seed derivation process linked strictly to the canonical English BIP39 mnemonic. Such a structured approach ensures security across different languages and clarifies the distinct encoding systems used, such as legacy French BIP39 and TZUR French display mnemonics. To avoid confusion, wallet identifiers like language codes and SHA256 hashes could be utilized to verify the exact wordlist being deployed, enhancing recovery accuracy and system portability.

The discussion also touches on the broader implications of ambiguous handling of mnemonic wordlists in multi-language setups. It explores strategies for optimizing wordlists to maintain security and clarity, such as employing non-standard sizes or specific word positions to differentiate from standard BIP39 encoding. These measures aim to help users accurately identify and use the correct seed phrase format, safeguarding the functionality of cryptographic wallets.

Finally, the proposal underscores the necessity of establishing a common convention that allows wallet developers to offer a standardized native-language recovery experience while ensuring full compatibility with the canonical English BIP39 phrases. This convention would not only address the UX challenges faced by non-English speakers but also contribute to the Bitcoin ecosystem by simplifying the recovery process across diverse linguistic backgrounds. Daniel emphasizes that this initiative does not seek to overhaul BIP39 but to enhance its applicability and safety, proposing a shared methodology that could be adopted by other wallet developers without altering the fundamental cryptographic framework.