Add BIP85 functionality

[aido]

---
title: One Seed to rule them all - Multi wallet
---
flowchart TB
    1.1 --> |Backup| 1.2
    1 --> |BIP85 Child 0| 2.1.1
    1 --> |BIP85 Child 1| 2.1.2
    1 --> |BIP85 Child 2| 2.2.1
    1 --> |BIP85 Child 3| 2.2.2
    1 --> |BIP85 Child 4| 2.3.1
    1 --> |BIP85 Child 5| 2.3.2
    1 --> |BIP85 Child 6| 2.4.1
    1 --> |BIP85 Child 7| 2.4.2
    subgraph 1[Parent]
        direction TB
        1.1[Root Seed]
        subgraph 1.2[2-of-3 Shamir's Secret Shares]
            direction BT
            1.2.1[Share 1]
            1.2.2[Share 2]
            1.2.3[Share 3]
        end
    end
    subgraph 2[Children]
        direction TB
        subgraph 2.1[Cold Wallet]
            direction LR
            2.1.1[BIP39 #1]
            2.1.2[Password #1]
            end
            subgraph 2.2[Hardware Wallet]
            direction LR
            2.2.1[BIP39 #2]
            2.2.2[Password #2]
            end
            subgraph 2.3[Lightning Wallet]
            direction LR
            2.3.1[BIP39 #3]
            2.3.2[Password #3]
            end
            subgraph 2.4[Phone Wallet]
            direction LR
            2.4.1[BIP39 #4]
            2.4.2[Password #4]
            end
    end

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[dzid26]

For people already having a BIP39 mnemonic, I imagine they could reuse it as a BIP85 root (https://iancoleman.io/bip39/ ShowBIP85)?

This would be beneficial in the context of inheritance simplicity - that is at the very least the heir could discover a valid wallet by treating the root seed as BIP39 and in the future if they figure out how to do BIP85 they could find children BIP39s.

Am I not mistaken?

[aido]

Yes.

Ian Coleman's BIP39 Mnemonic Code Converter is a great tool but it is online so I would never use my real seeds with it. That is why I am thinking of adding BIP85 functionalty to my app, so some of the utilities offered by Ian Coleman's tool can also be performed on an airgapped and secure Ledger device.

I shall be renaming the app from app-sskr-check to app-seed-utils in the not too distant future as this will better describe the apps funtionality

[aido]

@amanone has asked what the ETA is for BIP85.

The latest pull request LedgerHQ#5 presents an "Under Construction" screen when the BIP85 option is chosen on Stax and Flex devices . This pull request is primarily a port of the app to Stax and Flex. Once this pull request has been reviewed by Ledger, merged into v1.8.0 of the app and I am happy all is working well on all devices I will then begin work on adding the BIP85 options.