How does ledger generate the public keys?

Question

How does the ledger HW wallet generate the public keys it exports to multi-account wallets like Nami/Typhon?

Based on this post by them, it sounds like it might be:

• Parent private key is derived from master seed
• Many child private keys are generated from the parent private key
• The public keys are then generated - one for each child private key

The reason I'm asking is I want to know if I share my Account#0 with someone, do they have a way of knowing my Account#1...n? I looked at the BIP32 standard and it sounds like the answer is no but wanted to check because an additional twist for cardano is the staking address is embedded in the public addresses.

A practical case for this being important is if you do a transaction with someone using Account#0, you don't want them to know your other accounts.

Answer 1

Before activating the accounts feature, I wanted to be sure I can still access my funds even if the wallets using this feature will all disappear (adalite.io, ccvault.io and typhonwallet.io). So I tested it myself with cardano-hw-cli and my ledger device. The default account starts from the derivation path:

• 1852H/1815H/0H/0/0 for the payment keys, and the last "0" increments for each ne wkey
• 1852H/1815H/0H/2/0 for the staking key. The #1 account starts with:
• 1852H/1815H/1H/0/0 for the payment keys
• 1852H/1815H/1H/2/0 for the staking key And so on: 1852H/1815H/2H/ for the account #2, 3H for the account #3...

I generated a few payment keys and the staking key for the first 5 accounts, then I generated the addresses from them, and compared them with the addresses displayed in the web wallets, and they matched.

Regarding you actual curiosity, I don't think there is any possible way for someone to make a connection between your different accounts. Your payment addresses from one account will be generated from a payment public key and the staking public key, so of course they will be identified by blockchain explorer as being from the same wallet. But I don't see how the different accounts could be linked together.