PQ-single-address-backup - BIP-38 for P2MR (bc1z) - 104-char encrypted backup format

In the realm of cryptographic standards, particularly for wallet interoperability and recovery procedures, several critical considerations emerge. The inclusion of self-describing formats in binary payloads is paramount. Without clear identifiers like version numbers or algorithm specifications embedded within the payload, wallets face challenges in distinguishing between different profiles or recognizing incorrect wrappers. This necessitates the integration of human-readable lines such as ALG/KDF/ENC that are not merely optional but essential for accurate decoding processes.

Furthermore, defining a user experience (UX) for recovery operations is equally important. Features such as checksum validation or typo detection prior to executing Key Derivation Functions (KDFs), along with providing explicit feedback when an incorrect password is entered, enhance security and usability. It's also crucial to include test vectors that address scenarios involving corrupted backups, ensuring robustness across various failure cases.

For paper-based backups, which are intended to be durable over long periods, the reliability of failure responses is as significant as the compactness of the encoding used. A fixed 104-character limit has been suggested to facilitate easier scanning or transcription. However, this approach raises questions about whether the benefits of such a rigid format outweigh the flexibility and additional security that could be achieved by incorporating versioning directly within the authenticated payload itself. These strategic decisions play a pivotal role in shaping effective and secure cryptographic protocols.