BIP352 private key formats

The discussion revolves around the functionality and application of SP descriptors in the realm of cryptocurrency transactions, specifically addressing their capacity to include private key information. It is acknowledged that SP descriptors, in their current public form, operate on a meta-level, wherein the scriptPubKey generated is indirectly related to the transaction inputs rather than being a direct representation of the descriptor's content. This understanding lays the groundwork for considering the inclusion of private keys within these descriptors.

The conversation further explores the notion that output descriptors containing private key material, such as WIP or xprv, are essentially an enhanced version of their public counterparts, which would use a hex pubkey or xpub respectively. The primary difference lies in the added layer of including private key data, serving not just as a method of simplification but also as a means of conveying sensitive information securely alongside the public data. This approach is posited as a logical extension for SP descriptors, suggesting an adaptation to allow encodings that encompass private key material. Such an adaptation would not only maintain the equivalence to the public version of the descriptor but also facilitate the transmission of private keys in a manner deemed secure and efficient within the cryptographic and programming communities involved.