To convert your mnemonic phrase into a private key for signing trasactions, each wallet (hardware or software) performs a key derivation. The Oasis Protocol Foundation standardized the key derivation for official Oasis wallets in a document called ADR 0008 back in January 2021. However, the Ledger hardware wallet already supported signing transactions at that time using a custom (we now call it legacy) derivation path which is incompatible with the one defined in ADR 0008. Later, in Oasis app for Ledger v2.3.1 support for ADR 0008 was added so the wallet can request either derivation from the Ledger device.
The key derivation path defined in ADR 0008 has the following advantages compared to the legacy one:
- Derivation path is shorter which results in approximately twice as fast key derivation (and transaction signing) without compromising security.
- In case your Ledger device is broken or lost and you are unable to retrieve a new one, you will be able to import your Ledger mnemonic and restore your private key in any Oasis wallet which implements ADR 0008.
For reasons above, we recommend the usage of ADR 0008. However, since there are no security considerations at stake, Oasis wallets will support legacy derivation on Ledger for the foreseeable future.
If you happen to import your Ledger mnemonic to a software wallet, consider that mnemonic potentially exposed/compromised, i.e. not appropriate for a hardware wallet mnemonic anymore. If you use a new hardware wallet in the future, never restore it from the mnemonic that was previously used by any software wallet!