Bitcoin Forum

Bitcoin => Hardware wallets => Topic started by: lecomputer on January 05, 2018, 02:26:27 AM



Title: Ledger Nano S question, changing receive address and offline sends...
Post by: lecomputer on January 05, 2018, 02:26:27 AM
Hi

I have just set up my Ledger Nano S. I have a question...

- Is it ok to store my receive address on my computer so I can send BTC to my Ledger without having it with me? I guess if I dont have the receive address and the ledger is in its safe place there is no way to do it. I know that each time you use the receive address it is changed for security reasons, but does this mean I shouldn't store a receive address for use in the situation described above?

Thanks


Title: Re: Ledger Nano S question, changing receive address and offline sends...
Post by: mk4 on January 05, 2018, 03:25:22 AM
The receive address indeed changes after every transaction, but you can still re-use old receive addresses and receive funds safely.

And yes, you can safely store your receive address on your computer or anywhere, as no one can do anything to your funds with your receive address, besides just looking up how much bitcoin you're holding.


Title: Re: Ledger Nano S question, changing receive address and offline sends...
Post by: lecomputer on January 05, 2018, 03:27:01 AM
Thanks

But if they are changing addresses each time for security is it best not to store an old address to use when I am not near my Ledger Nano?

I'm quite new to all this :)


Title: Re: Ledger Nano S question, changing receive address and offline sends...
Post by: mk4 on January 05, 2018, 03:35:57 AM
Thanks

But if they are changing addresses each time for security is it best not to store an old address to use when I am not near my Ledger Nano?

I'm quite new to all this :)

They're not changing the addresses for security, but for anonymity changing the addresses for both security AND anonymity. It just makes it harder for people to track how much bitcoin you have, using a block explorer like the blockchain.info[1] explorer. Should you re-use an old address? That's completely up to you. Remember: The bitcoin blockchain is public. So if a certain person knows your wallet address, he/she can look it up online to see how much bitcoin that wallet is holding.

[1] https://blockchain.info

EDIT: Thanks Lauda for correcting


Title: Re: Ledger Nano S question, changing receive address and offline sends...
Post by: Lauda on January 05, 2018, 10:04:02 AM
They're not changing the addresses for security, but for anonymity.
No. It's the case for both. Until you spend from an address, you aren't showing your public key to anyone. That is *fine* for now as there is no security flaw in Bitcoin or the relevant algorithms (we can ignore ASICBoost). So what happens when ECDSA is compromised, let's say due to a quantum computer? Any address that was reused, and still has funds on it, is unsafe. Given the exploit, someone could reverse engineer the private key from that public key.

Tl;dr: It's both for privacy and security. Address re-use is not recommended. Avoid where possible.