Address derivation details of Ledger app

[farukterzioglu]

Address derivation details of Ledger app

[jleni]

That's SLIP0010 and it is known to be problematic for ed25519 when paths are not fully hardened.
SLIP-0010 was actually designed for secp256k1 not ed25519.

Ledger's "NORMAL" derivation approach for ed25519 is to use ed25519+bip32 (cardano like) not SLIP0010

[jleni]

if you are interested in how Ledger derives keys in ed25519+bip32, they published a simplified python example here:
https://github.com/LedgerHQ/orakolo/blob/master/src/python/orakolo/HDEd25519.py

You can also find interesting to look at the paper from Dmitry Khovratovich and Jason Law.

[jleni]

this can also be useful as a reference

https://github.com/LedgerHQ/nanos-secure-sdk/blob/e3293938e5988e1ffa05d1f2ba23db431275f21c/include/os.h#L1169-L1182

[jleni]

I hope this provides a more complete picture.

[farukterzioglu]

Thanks a lot @jleni it helped.