Wasabi Wallet Shows Public Key - Privacey Concerns

[McMurdo]

I've noticed that when you generate a new address in Wasabi, it shows the address' public key next to the QR code. This gives your counterparty an easy opportunity to take a picture of that public key.

Obviously one person seeing one public key isn't the end of all your privacy, but (extra quantum protection aside) is there any privacy and/or security disadvantage to your counterparty learning the public key of the address they're sending to?

Thank you

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[crairezx20]

The public key is just your BTC address once you send BTC to other bitcoin address only the recipient knows your BTC address but if you post your wasabi bitcoin address in public even here in the forum your BTC address is not private anyone can see your BTC address and can monitor your receiving and sending transactions.

That is why they have a coinjoin feature*(It is known as mixing service) where you can send BTC anonymously without using your BTC address from your wasabi wallet.

No one can track your transaction if you use the coinjoin feature.

[McMurdo]

crairezx20:
Right, so normally, your counterparty only knows that's address' pub key along with the rest of the network when you spend from that address.

I've heard how this provides a little bit of extra protection from the threat of future quantum computing, because if you spend from an address only once, then the network only sees that pub key for a few minutes in the mempool before the next block is mined ontop of it.

I'm wondering if there's any other privacy/security concerns coming from your counterparty learning your address' pubkey before you spend from it (besides a little extra protection from the tiny threat of them having having access to future quantum computing). 

and yes, I understand the basics of why mixing is important.

[khaled0111]

The public key is just your BTC address

Actually, btc address or public address is derived from the public key using some hashing algorithms.
I think OP here is talking about the public address since it is it what is being shown when creating a new address on Wasabi. (Correct me if I'm wrong)
I don't think this imply any risk since your public address is meant to be shared. Also, if Wasabi doesn't show your address in plain text, whoever monitoring your screen can simply extract it from the QRCode by using any online decoder.

[McMurdo]

khaled0111:
Wasabi shows the QR code for the address, but right next to that for reference it shows the public KEY for that address.

Since your counterparty is scanning your screen for the address QR code, they can get that public key. also. Obviously that can't steel your coins with that, just wondering if there a some negative privacy effects to them having that public key before you ever spend those coins to the network and reveal the public key.

[Mashfiqun]

You should be more concerned about exposing Private Keys than Public Keys. Your private key is the thing that's sensitive. You can lose your funds if you leak your private key.

[khaled0111]

Obviously that can't steel your coins with that, just wondering if there a some negative privacy effects to them having that public key before you ever spend those coins to the network and reveal the public key.

Yes, your funds are safe and there is no risk regarding your privacy as all they can do with your public key they can already do it with your public address.
Your privacy may be at risk only when your xPUB key is disclosed.
By knowing your extended public key, an attacker can extract all your wallet public keys. Hence, he will be able to know about all transactions you make from that wallet and how much bitcoins you have on it.

[o_e_l_e_o]

Obviously one person seeing one public key isn't the end of all your privacy, but (extra quantum protection aside) is there any privacy and/or security disadvantage to your counterparty learning the public key of the address they're sending to?

No.

It's called a public key for a reason. When using cryptography outside of bitcoin, your public key is generally distributed freely. As you point out, the public key of every address which has ever had an outgoing transaction is publicly known. If there was a security risk to revealing it, then millions of coins would have been stolen by now. The only theoretical security risk is if someone develops a way to reverse the hashing process and turn a public key back in to a private key, which is a potential for quantum computing but not for several decades yet.

There is no additional privacy risk. The public key which is revealed is the public key only for the single address which they are scanning anyway, and not your extended public key to all your address (sharing this extended public key would be a big privacy risk). They can't derive any of your other public keys or any of your other addresses from it. Any information they can gain from knowing that single public key (your balance and transactions from the associated address) they could similarly gain simply by knowing the address (which they will anyway since they are scanning it).

[figmentofmyass]

I've noticed that when you generate a new address in Wasabi, it shows the address' public key next to the QR code. This gives your counterparty an easy opportunity to take a picture of that public key.

"counterparty" implies the two of you are transacting. if a counterparty is sending you BTC then he already knows that public key. that's how bitcoin works, by leveraging public-key cryptography.

this actually isn't limited to wasabi wallet or the bitcoin protocol. even with privacy technology like monero stealth addresses, the sender and receiver of any transaction can still determine where a payment was sent. they will always know because they were party to the transaction.

bitcoin's transparent UTXO ledger does make for additional privacy concerns, particularly where counterparties know your identity. if you don't want your counterparties to be able to perform cluster analysis on your wallets, you need be wary of what you do with the outputs they send you. this is why the biggest customers of bitcoin mixers are exchange users trying to obfuscate where their coins went.

[dkbit98]

I am wondering, if you get you public key exposed in public,
can other people more easily connect all your generated public addresses, and that way reduce your privacy?

[HCP]

"counterparty" implies the two of you are transacting. if a counterparty is sending you BTC then he already knows that public key. that's how bitcoin works, by leveraging public-key cryptography.

That's not strictly true... If I tell the counter party to send to "1PQt7uqFwrrUBKSEo5MxNK355JrFuiV9Tg"... then they have the hash (of a hash + some other bits) of my public key... but they don't have the public key itself. There is no way they can convert from "1PQt7uqFwrrUBKSEo5MxNK355JrFuiV9Tg" to "02BCF1E101DD5DA48A8FE26CE72F22DE8E42BBA39D782FCC1F8FE11745D83068F2" (without other things, like a signature)

Not that it really makes a difference from either a privacy or security point of view. There isn't a lot anyone can do with either unless you've been stupid and linked UTXOs by being careless when creating spending transactions.

But I think it is an important distinction between "public key" and "address".

I am wondering, if you get you public key exposed in public,
can other people more easily connect all your generated public addresses, and that way reduce your privacy?

Short Answer: No.


Longer Answer:
Public Key = No
Master Public Key = Yes

[figmentofmyass]

"counterparty" implies the two of you are transacting. if a counterparty is sending you BTC then he already knows that public key. that's how bitcoin works, by leveraging public-key cryptography.

That's not strictly true... If I tell the counter party to send to "1PQt7uqFwrrUBKSEo5MxNK355JrFuiV9Tg"... then they have the hash (of a hash + some other bits) of my public key... but they don't have the public key itself.

yes, thank you for pointing that out. i was thinking strictly in terms of the privacy implications, not the distinction between pubkeys and pubkey hashes.

There isn't a lot anyone can do with either unless you've been stupid and linked UTXOs by being careless when creating spending transactions.

unfortunately, i think most people are careless when spending. they don't realize that regularly linking outputs together---even just by using default wallet settings---can expose most of their wallet history to outside observers.

[o_e_l_e_o]

Longer Answer:
Public Key = No
Master Public Key = Yes

To follow on from this, if you have somehow leaked your master public key, or someone else has accessed it, then I would recommend abandoning that wallet and transferring all your coins out of it and to a new wallet. Not only is it a big privacy invasion since the third party can derive and link all the addresses within that account, it is also a security risk. If the third party/attacker was to also gain access to a single private key to any of the addresses within that account, the combination of private key and master public key allows them to derive all your other private keys as well.

[McMurdo]

There is no additional privacy risk.

Thanks

[FireBallex]

I've noticed that when you generate a new address in Wasabi, it shows the address' public key next to the QR code. This gives your counterparty an easy opportunity to take a picture of that public key.

Obviously one person seeing one public key isn't the end of all your privacy, but (extra quantum protection aside) is there any privacy and/or security disadvantage to your counterparty learning the public key of the address they're sending to?

Thank you

Public keys is not alarming, i have seen where by a friend received bitcoin with public key and somehow he claimed it, the only thing you must safe from the public is your private keys