BIP39 Extension for Manual Seed Phrase Creation

The proposed method aims to empower users in the creation of their seed phrases, mitigating reliance on opaque processes by utilizing a systematic approach derived from a specific subset of words within a predetermined wordlist. This approach generates 16-word phrases, each embodying 128 bits of entropy without incorporating a checksum. The ingenious aspect of this methodology is the dual-purpose utility of each word: the majority of the bits contribute to entropy, while the trailing bits delineate the derivation path. This strategy offers a spectrum of seven distinct derivation paths based on uniformity in the least significant bits across all words in the phrase. Conversely, variability in these bits across the phrase unlocks the potential for encoding up to 48 bits of metadata, introducing an avenue for error detection akin to the functionality of a checksum.

This implementation bears several advantages. Firstly, it simplifies user interaction by reducing the necessity for detailed knowledge about seed phrase composition and wallet compatibility; users need only be aware of the number of words in their phrase and the capacity of their wallet to utilize this extension. Another benefit is its reliance on the same wordlist as a standard 12-word phrase, suggesting that this system could either supplement or revise the existing BIP39 standard rather than introducing an entirely new protocol. Additionally, the method's design inherently discourages random or naive word selection by constraining choices to every eighth word, thereby enhancing security similarly to the role of a checksum in traditional systems. The proposition also highlights the flexibility of this approach, noting the possibility of expanding the format to accommodate phrases of varied lengths—such as a 32-word phrase with equivalent entropy to a conventional 24-word phrase—while simultaneously providing for the incorporation of additional metadata uses.

In essence, the suggested framework not only fortifies the process of seed phrase generation through a blend of simplicity, security, and compatibility but also lays the groundwork for future adaptations and enhancements within the realm of cryptographic currency storage and recovery.