NIP-06
======

Basic key derivation from mnemonic seed phrase
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`draft` `optional`

[BIP39](https://bips.xyz/39) is used to generate mnemonic seed words and derive a binary seed from them.

[BIP32](https://bips.xyz/32) is used to derive the path `m/44'/1237'/<account>'/0/0` (according to the Nostr entry on [SLIP44](https://github.com/satoshilabs/slips/blob/master/slip-0044.md)).

A basic client can simply use an `account` of `0` to derive a single key. For more advanced use-cases you can increment `account`, allowing the generation of practically infinite keys from the 5-level path with hardened derivation.

Other types of clients may choose to get fancy and use other derivation paths for their own alternative purposes.

Because Nostr uses [Schnorr signatures standard for the curve `secp256k1`](https://bips.xyz/340), public keys have extra compression compared to Bitcoin ECDSA compressed public keys, meaning that the y-coordinate is not only omitted, but parity is not even indicated with the '03'(odd), nor '02' (even) prefixes. In other words, only the x-coordinate is included without any extra prefix marker. This matters in three contexts (there may be others):
 - When borrowing code from Bitcoin public/private key ECDSA cryptography. This will output 33-byte public keys with a 02/03 prefix (compressed) or 04 (uncompressed). The first byte (prefix) needs to be removed.
 - Conversion of a public key, to bech32. The pure x-coordinate value without prefix must be used as the input, not a compressed public key.
 
### Test vectors

mnemonic: leader monkey parrot ring guide accident before fence cannon height naive bean\
private key (hex): 7f7ff03d123792d6ac594bfa67bf6d0c0ab55b6b1fdb6249303fe861f1ccba9a\
nsec: nsec10allq0gjx7fddtzef0ax00mdps9t2kmtrldkyjfs8l5xruwvh2dq0lhhkp\
public key (hex): 17162c921dc4d2518f9a101db33695df1afb56ab82f5ff3e5da6eec3ca5cd917\
npub: npub1zutzeysacnf9rru6zqwmxd54mud0k44tst6l70ja5mhv8jjumytsd2x7nu

---

mnemonic: what bleak badge arrange retreat wolf trade produce cricket blur garlic valid proud rude strong choose busy staff weather area salt hollow arm fade\
private key (hex): c15d739894c81a2fcfd3a2df85a0d2c0dbc47a280d092799f144d73d7ae78add\
nsec: nsec1c9wh8xy5eqdzln7n5t0ctgxjcrdug73gp5yj0x03gntn67h83twssdfhel\
public key (hex): d41b22899549e1f3d335a31002cfd382174006e166d3e658e3a5eecdb6463573\
npub: npub16sdj9zv4f8sl85e45vgq9n7nsgt5qphpvmf7vk8r5hhvmdjxx4es8rq74h