Mettre à jour rfc/0019_Duniter_V2_derivation_path_convention_hd_wallets.md

rfc/0019_Duniter_V2_derivation_path_convention_hd_wallets.md

+# Duniter V2S conventions for Hierarchical Deterministic Wallet
 
+## Master seed generation
+
+Master seed should be generated from a [BIP-39-Mnemonic].
+
+## Key derivation
+
+Key derivation should use [Substrate-Derivation-Path] specifications.
+
+## Key derivation scheme
+
+First derivation step should be an hardened derivation and represent an `account_id`.
+
+    <mnemonic>//<account_id>
+
+`account_id` is an integer beetween `0` and `(2^24) - 1`.
+
+There are 3 types of accounts :
+
+| Account type | `account_id` value conditions |
+|-|-|
+| Member | `account_id == 0` |
+| Transparent | `account_id != 0 && account_id % 2 == 0`  |
+| Opaque | `account_id % 2 == 1` |
+
+* **Transparent:** Classic non-member wallet  (even)
+* **Opaque:** A wallet using single-use public keys for each payment received and for each payment to oneself (odd).
+
+### Opaque account derivation scheme
+
+For **self-payment**, it is first necessary to derive the so-called "internal keypair", by derivation `//1` from the opaque account keypair.
+
+    <mnemonic>//<account_id>//1
+
+Then, each single-use public key is obtained by soft derivation of the "internal public key".
+
+    <mnemonic>//<account_id>//1/i
+
+Where `i` is the payment to oneself number, beginning from 1.
+
+For **external payments**, it is first necessary to derive the so-called "external keypair", by derivation `//0` from the opaque account keypair.
+
+    <mnemonic>//<account_id>//0
+
+Then, each single-use public key is obtained by soft derivation of the "external public key".
+
+    <mnemonic>//<account_id>//0/i
+
+Where `i` is the public key derivation number, beginning from 1.
+
+[BIP-39-Mnemonic]: https://github.com/bitcoin/bips/blob/master/bip-0039.mediawiki
+[Substrate-Derivation-Path]: https://docs.substrate.io/v3/tools/subkey/
+
+### Examples
+
+#### Example 1
+
+* **Mnemonic:** `"acquire flat utility climb filter device liberty beyond matrix satisfy metal essence"`
+* **Seed:** `0xc7de9b8c771078445f31b7e7ce0ef58b588ac37f85359527b7267ac3ad2d25f5`
+* **Address:** `5HBUc4C28AWThgPZ47TKoY9RTebMJbkfrLKWveWH6EzfAye4`
+
+* **Account ID:** `1`
+* **Type:** Opaque
+
+* **First External Public Key**
+* **Path:** `"acquire flat utility climb filter device liberty beyond matrix satisfy metal essence//1/0/1"`
+* **Address:** `5CcNUmAo5P4K9LC68fgqFKNDTcxZ7zheLeLgk4mnADXeor2K`
+
+* **Third External Public Key**
+* **Path:** `"acquire flat utility climb filter device liberty beyond matrix satisfy metal essence//1/0/3"`
+* **Address:** `5FpnSswqc97MScQ8cvEjXcT13kNBuNArJKFCxUU6SqeYoBrN`